# When to change Mk1 cambelt?



## emtiem (Jan 17, 2011)

I've heard many say that the cambelt needs changing at 60k even though the manual says 80K, but I notice that the TT Shop also recommend 80K; I'm looking to buy a TT at just under 60K on the clock and need to know whether I'd be justified in getting him to change it or not. I've even called an Audi dealer and they still say 80K; I'm not sure I have much evidence I can show him to get him to change it.


----------



## jamman (May 6, 2002)

Change it


----------



## stefmcd (Feb 27, 2011)

I share op's situation - my 5 year old QS has done 42K miles. Should I bite the bullet and replace or should it have a good bit of life left? Could not changing quickly lead to a massive bill?


----------



## emtiem (Jan 17, 2011)

I know it's best to change it, but I'm trying to get a second hand dealer to change it for me as part of a sale (or offer money off), but I have no way to prove it should be changed; especially as the manual says 80K, and so does an Audi dealer. Is there any *official* Audi statement saying it should be changed at 60K?


----------



## nikos525 (May 15, 2006)

I remember reading that Audi changed the recommended mileage, but IIRC it's either the mileage or 5 years. Just had mine changed due to the 5 year period, there was no wear on the belt & the water pump was fine.


----------



## Portent (Mar 12, 2011)

CUrrently looking for a car and all the I've read point to changing it at 60k miles or 5 years whichever is the soonest (the official Audi advice is 80k). If it were me I'd just assume it needs doing and work out how much the car is worth to me based on that. Then tell the dealer the price you're prepared to buy it for. If he won't take it then walk away and get another car. At the end of the day you don' have to prove to the dealer that it needs doing. You just have to know how much the car is worth to you.


----------



## Craigie Boy (May 22, 2007)

My car has just turned 45k miles and I had it serviced last week at an independant garage. He's a former Audi Head Tech and he suggested I get it done soon. Car is 2003. He also uses only VAG genuine equipment and quoted £250 fitted which I was well chuffed with, so next month it's going in.


----------



## DDcrash (May 5, 2009)

stefmcd said:


> I share op's situation - my 5 year old QS has done 42K miles. Should I bite the bullet and replace or should it have a good bit of life left? Could not changing quickly lead to a massive bill?


Do you feel lucky? Well do you? 8)


----------



## fishface (Nov 25, 2006)

Had mine done at 60K along with the water pump.
The water pump had half the impeller missing, I was pretty glad I decided to do it all then, and for £300 I have peace of mind!


----------



## the_cleaner_1 (Sep 1, 2009)

I tried to get the garage who sold me my TT to change it as part of the deal...car had done just shy of 70k and they didn't want to know. The car was spotless, however, and I bought it anyway, the cambelt was done a week later along with the water pump. 
Peace of mind. Well worth the money.


----------



## wul (Feb 10, 2009)

Craigie Boy said:


> My car has just turned 45k miles and I had it serviced last week at an independant garage. He's a former Audi Head Tech and he suggested I get it done soon. Car is 2003. He also uses only VAG genuine equipment and quoted £250 fitted which I was well chuffed with, so next month it's going in.


Is that price with the relevant tensioners and pulleys? The few cases iv read about on here it's not the belt that snaps it's the tensioner that go,s


----------



## stewram (Sep 18, 2008)

My cambelt went just after 79,000 miles. CHANGE IT! It's a very expensive lesson to learn...


----------



## Clarke (Nov 11, 2006)

If you are planning to change Cambelt there are various other things you might as well do as access to those parts are easier. I got mine done from Audi, was the first thing I done on my car before any mods, my millage was 54k.

I spoke with a few enthusiast who gave me a long list of what to replace during cambelt, like water pump, stretch bolts etc, which was all done.


----------



## SVStu (Dec 11, 2006)

Best to change em just before they snap :lol:

Just because a dealer says they have changed it doesnt actually mean they have  Better to get the cash off and get it done yourself by and indi you trust, plenty will recommend ones on here.

Most people usually "test" their cars when just purchased, possibly stressing the car more than the previous owner, I dont think I'd trust a belt more than 5 years old when giving it some beans  , not worth the expensive risk, its always a good selling point too if you can show you spared no expense when maintaining.


----------



## Hoggy (May 8, 2002)

Hi, Audi latest recommendation is 75K or 5 years which ever comes sooner, Forums is 60K or 5years.
Audi latest price is £399 plus Hyd tensioner plus water pump,which should also be replaced & are not part of the Audi kit & not replaced unless you ask. Find a reliable Indy by asking on Forum with your location.
Hoggy.


----------



## TT SMITHY (Jan 18, 2011)

this is from JKM website V.A.G now recommended renewal of Cambelt Kit (including tensioners) & waterpump (when applicable) every 60,000 miles or 4years which ever comes first.


----------



## dazzadrew1 (Feb 6, 2010)

bought mine 45k 10 year old no cam belt change [smiley=bigcry.gif]

first thing done new cam belt new waterpump kit sleepin easy at night [smiley=sleeping.gif]

change it


----------



## benfunktion (Jan 24, 2011)

Anyone got any idea of a way of telling if it's been done already with no service history.. i'm about to hit 100k and all my paperwork got burned in a house fire or was it eaten by the dog? hmm


----------



## Hoggy (May 8, 2002)

Hi Ben, Unless replaced very recently, no way to tell without paper work. Audi CS latest is 5 years or 75K miles. Audi dealers price is £429 & that doesn't include water pump or Hydraulic tensioner, so over £500 at Audi dealer, so find a good Indi & make sure Hyd tensioner is replaced as well.
Hoggy.


----------



## pfgascoigne (Apr 7, 2011)

Hi Hoggy,

You and I have had a discussion about the belt "slack side" hydraulic tensioner before. You don't need to change it unless its showing signs of damage.


----------



## gunner (May 18, 2002)

Originally, when first built, Audi recommended cambelt changes at 115k (and that what is quoted in my 2001 TTC service book). However after a spate of failures and threat of class action law suit in the US, the change interval was reduced to 60k.

Either way, if the belt is over 5 years old it should be changed and in addition, its not only the belt which needs changing. The following additional items should be renewed when doing a cambelt :-
- water pump, whilst its all apart its well worth changing this, they cost anywhere from £25 to £60 
- Tensioning damper, these allow some flexibility in the belt but have a habit of seizing causing excess tension in the belt and ultimatley failure
- tensioning roller, simply a ball bearing roller allowing the belt to change route, these can also seize
- engine mount bolts, there are four 'once use' stretch bolts which should be changed
- aux drive belt, used for air con & alternator drive
- G12 coolant
- Power Steering fluid

As already mentioned, many garages dont include the tensioning damper in the quote, so try to get one that does.


----------



## st3v3 (Apr 9, 2007)

gunner said:


> Originally, when first built, Audi recommended cambelt changes at 115k (and that what is quoted in my 2001 TTC service book).


I read the very same in my TTR handbook which bothered me ALOT as my car had 75000 on the clock and is an 04 plate with no evidence what so ever of a cambelt change.
So after £325 was taken from my wallet im all happy now.


----------



## pfgascoigne (Apr 7, 2011)

gunner,

Can you please explain your statement about the tensioning damper.


----------



## jakon316 (May 22, 2011)

Ours is on 67000miles and has been changed 3 times already first time the owner before us never got proof so we asked the dealer who we bought from to fit again just incase they had lied and then they fitted the belt a tooth out so needed it redoing


----------



## Hoggy (May 8, 2002)

pfgascoigne said:


> Hi Hoggy,
> 
> You and I have had a discussion about the belt "slack side" hydraulic tensioner before. You don't need to change it unless its showing signs of damage.


Hi, Yes I remember, but still don't agree that Hyd tensioner does not need replacing. It may look O.K. at belt change, but what about in the following years. Saving £75 approx is not worth the risk. 
I know Audi have faith in it, but would they replace engine FOC, because it failed & they didn't replace it. 
Hoggy.


----------



## wireless (Jan 24, 2012)

Hoggy said:


> pfgascoigne said:
> 
> 
> > Hi Hoggy,
> ...


pfgascoigne I would have the damper replaced if I were you or there could be a serioulsly bill later on if it does fail big time as Hoggy has stated.

Good luck


----------



## higsta (Nov 29, 2011)

So rather than spend ages looking for a car with the cam belt and water pump just done it would probably be better to get one that hasn't (with appropriate price reduction) and then get the following done:



> - water pump, whilst its all apart its well worth changing this, they cost anywhere from £25 to £60
> - Tensioning damper, these allow some flexibility in the belt but have a habit of seizing causing excess tension in the belt and ultimatley failure
> - tensioning roller, simply a ball bearing roller allowing the belt to change route, these can also seize
> - engine mount bolts, there are four 'once use' stretch bolts which should be changed
> ...


I'm sure lots of people have had the cam belt done as they say but I wonder how many went the whole 9 and did all the above.


----------



## simononly (Aug 16, 2011)

Looking to get my cambelt changed, but bulked at the Audi price of £429, esp if I need to get water pump etc done at further cost.

Happy to go to an independent, but can anyone do these? Not sure about local indies around Oxford area. Anyone have any advice?

End of the day if it's easier/better to go to Audi I will just pay it, just it seems a lot of money!


----------



## wireless (Jan 24, 2012)

One of the specialists in the forum can do it as I've read a lot about him on other posts and have read many interesting things on his web site regards mods etc etc.

Wak box mod, double brake light mod.

They call him Wak and hes probably not too far from you either.

Up to you at the end of the day.


----------



## bobclive22 (Apr 5, 2010)

This is an email I received from the Sytner group, not timing belt change.

To [email protected]
Good Morning Mr Leeson,

Further to our telephone conversation earlier today, please see below the details of the 05 plate Audi TT Roadster,

Owners:
The car has had 4 owners the last change was 11/11/05 and the car moved from Bury to Sheffield.

Mot:
The car has MOT until Feb 12 so as per our Sytner Select standard it will be supplied with a new 12 month MOT certificate.

Service History:
Pre Delivery inspection - 31/03/05 - 0miles - Lincoln Audi
Service - 1/12/06 - 5800miles - Smith Knigh Fry Audi
Service - 16/10/07 - 9605miles - Huddersfield Audi
Service - 22/09/09 - 25082miles - Sheffield Audi
Service - 29/03/11 - 33706miles - Walter Cutting

This is due a service now so when sold it would come fully serviced, the cam belt on the TT is due on mileage not time so is required to be changed at 60,000 miles

Business Manager
Tel: 01865 863221
Fax: 01865 864883
Mobile: 07517 989819
Email: [email protected]


----------



## st3v3 (Apr 9, 2007)

bobclive22 said:


> This is an email I received from the Sytner group, not timing belt change.
> 
> To [email protected]
> Good Morning Mr Leeson,
> ...


Remember he is a business manager and needs to make money, on that basis i would push for a cambelt change as it has been nearly 7 years from new, regardless of mileage.


----------



## straut (Aug 31, 2011)

Well i think every single person on here has been through this and the answer is simple
1,cars before 2004 timing belt change 115,000 miles (miles)its in your book audi will not make you change it any sooner its up to you,they will however "recommend" you to do it.
2,cars after 2004 they changed it to 75,000 miles or 5 years and that is thier stance right now(it was changed to this due to some failures) this is all Audi talk not mine

http://www.audi.co.uk/owners-area/maint ... nance.html

click cambelt change and have a read

pre 2004 115,000 no time limit ??

2004 75,000 miles or five years

or the recommended interval by good indies and this very site which i think is 60,000 or 4 years (sounds good to me)

personaly on an engine that can destroy itself if it snaps\slips i will change it sooner rather than later
do what i did and phone the dealer it was serviced and ask them if its been done and if it hasnt then toss the coin
but before you buy an exhaust,wheels,filters etc the first thing you need to do is make suree its been done

bobclive22 you need to contact the last dealer that serviced the car as because its an 05 car it SHOULD of been done on the 5 year basis regardles of mileage
steve


----------



## DuTTchNL (Sep 18, 2010)

I bought mine with a snapped belt!

Took 2700 euro to return it running...

My mechanic works for Audi, for about 20 jears now.

Sorry for the metric.. System he says change it at 120 tot 140.000 km

Any later is asking for trouble (Audi reccomends 160 tot 180.000) most have snapped by then


----------



## Hoggy (May 8, 2002)

Hi, I wonder why a cambelt on a pre 2004 TT doesn't deteriorate with time. The Audi statement doesn't make sense.

Vauxhall cambelt replacement for VXR Corsa is 100k miles or 10 years which ever comes first. I wonder if that will change, if they do start to fail earlier.

Hoggy.


----------



## gunner (May 18, 2002)

pfgascoigne, I will try to explain what my understanding of the cambelt tensioning mechanism is on the 225 TT :-

The cambelt is driven by the crank pulley and drives the camshaft pulley which inturn drives both camchafts.

The cambelt is routed to the camshaft pulley via the tensioning roller which is mounted eccentrically. This mounting allows either tension or slack in the belt depending on the position of the roller.

In order to provide sufficient tension on the belt, the tensioning damper pushes on the tensioning roller. The damper will also allow some slack if there is too much tension. This is all done automatically by the tensioning damper which is basically a spring with oil damping.

Over the years the tensioning damper can seize thereby preventing any slack in the belt, alternatley they can leak and not provide any damping effect, this is why it should be changed.

When I changed the cambelt on my 2001 TTC last year, I found the tensioning damper had seized. Given that the car is now 10 years old and it hadnt been changed before, this wasnt a big suprise and so I would recommend getting it checked when the cambelt is done.


----------



## straut (Aug 31, 2011)

Hoggy said:


> Hi, I wonder why a cambelt on a pre 2004 TT doesn't deteriorate with time. The Audi statement doesn't make sense.
> 
> Vauxhall cambelt replacement for VXR Corsa is 100k miles or 10 years which ever comes first. I wonder if that will change, if they do start to fail earlier.
> 
> Hoggy.


well it didnt till 2004 they do after 4 years of age though ha ha
But on another note would you leave a vxr for 10 years with no belt change.........


----------



## pfgascoigne (Apr 7, 2011)

Hi Hoggy,

You (and most others!) and I disagree on this subject. However I have the might of Audi on my side, they don't change the tensioner as part of a cam belt change unless you ask and pay. And if you believe that they would fit you a free engine if something happend after they had done the job.....then you faith in the main dealers is greater than mine.

wireless,

I did my cam belt but I didn't change the hydraulic tensioner. Time will tell, but we're at 10000 miles and all is well so far.


----------



## Hoggy (May 8, 2002)

Hi pfgascoigne, No I *don't* believe Audi would replace engine FOC, which is why I believe Hyd tensioner should be changed with cambelt. If you have Audi on your side, will they replace your engine FOC, as you believe as they do, it doesn't require replacing with cambelt.
Hoggy.


----------



## wolff1 (Jul 25, 2010)

I don't believe in the - expensive on the crumbs, cheap on the bread. For a 40£ more, not changing the tensioner is an extra headache for me, we're driving TT's not 300£ crap, not to care, anyway...


----------



## wireless (Jan 24, 2012)

pfgascoigne said:


> Hi Hoggy,
> 
> You (and most others!) and I disagree on this subject. However I have the might of Audi on my side, they don't change the tensioner as part of a cam belt change unless you ask and pay. And if you believe that they would fit you a free engine if something happend after they had done the job.....then you faith in the main dealers is greater than mine.
> 
> ...


pfgascoigne, I have repaired Vag Turbo'ed cars that have had replaced the cam kits but left the the damper out of the replacement and "poof" there go the valves!. £12-£16 each valve when you know who but then its a case of timing belt off and advisory replace, head off cams out, damaged valves out and refit which is a very costly process and I do wish it doesn't happen to you as you haven't had the tensioner replaced by the word of the Audi who we all know to be called "stealers" for a very good reason!. :wink: :lol: 
I replaced all components for a good reason, to be sure there is no extra expense where it is not necessary and more to spend on mods :roll: :wink:

Best of luck for the future


----------



## jqhn80 (May 21, 2011)

Hi, is there anyway to tell if the hydraulic damper is on its way out? The previous owner of my car had changed belt, water pump, hydraulic tensioner but not the damper.


----------



## Hoggy (May 8, 2002)

Hi jqhn80, Hydraulic tensioner/damper is the same part, if you are sure it was a Hydraulic part, then will be O.K. 
There is a tensioner in Audi cambelt kit, but that is just a roller.
Hoggy.


----------



## jqhn80 (May 21, 2011)

Hi Hoggy, to be sure i'll have to look again at the service history booklet, but from memory i think it said just "tensioner" among the other things and i presumed (wrongly?) it was the hydraulic one. The cambelt change was by an indy garage, not the dealers. I'll get back to you on this one.


----------



## TT-TOM (Feb 15, 2012)

Hia, I've just bought a 2003 TT 225 quattro with 62K on the clock. It had the cambelt and tensioner changed at 40K about 2 and a half years ago.

This make me a little angry because now for piece of mind i think i'm going to have to do the job properly this summer and change the lot again but this time do the water pump and hydraulic damper aswell.

Do you think its worth doing or am i just being paranoid?

EDIT: or i could just inspect the hydraulic damper and see if its seized. I think i might do this first


----------



## Hoggy (May 8, 2002)

Hi Tom, I'm sure it's worth doing, the problem is now you know, you will worry about every time you start her up.
There must be 1000s of TT with Full Audi service, who are still using the original hyd tensioner.
Hoggy.


----------



## TT-TOM (Feb 15, 2012)

Thanks for the reply Hoggy, What I might do first is do an inspection on the damper to see if its seized or leaking. If its looks ok i might postpone the cambelt change till it gets to 4 years. (as i'm a 60k or 4 years kind of guy)

Does anybody have experience on how much resistance there should be in the damper, should i be able to move it by hand or will i need some leverage?


----------



## wolff1 (Jul 25, 2010)

TT-TOM said:


> Hia, I've just bought a 2003 TT 225 quattro with 62K on the clock. It had the cambelt and tensioner changed at 40K about 2 and a half years ago.
> 
> This make me a little angry because now for piece of mind i think i'm going to have to do the job properly this summer and change the lot again but this time do the water pump and hydraulic damper aswell.
> 
> ...


Do it, because of the water pump mostly, it can become a problem. If I'm you, I'll change everything anyway, dayco says, if you change a part of the cambelt system, you have to change the belt also...


----------



## TT-TOM (Feb 15, 2012)

I wouldn't change the damper without changing the rest of the system. I just think its pointless changing it all if the damper is ok.

However you do have a point about the water pump. I know they are common for failing as a pump with broken impellers causing overheating but that's not really a huge concern as you can soon turn off the car as soon as the needle goes up.

But is the bearing/pulley prone to failing/seizing. This is my main worry about running on the original water pump.


----------



## Hoggy (May 8, 2002)

Hi Tom, Never heard of a water pump bearing failing/seizing & a disintergrating impellor could cause overheating or perhaps a part of it jamming thermostat open, but nothing disastrous.
I'm told most impellors break when removing pump, because of the very tight fit, if true, I don't know.
Hoggy.


----------



## wolff1 (Jul 25, 2010)

Change whatever you want, it's your cars...


----------



## TT-TOM (Feb 15, 2012)

hmmmm, Wolff1 is probably right. with the amount of stuff you have to take off to even get to the timing belt to look at it, its probably worth going in and doing the job right and replacing everything.

Its just annoying when Audi should do the job right in the first place. :x They think its acceptable to replace half the timing belt components yet i bet if i went to my local garage they would advise me to replace everything.

Its times like this i wish i had no mechanical knowledge, it would be so much nicer being worry free from everything. Well, until the timing belt snapped and i had to buy a new engine!


----------



## wolff1 (Jul 25, 2010)

TT-TOM said:


> hmmmm, Wolff1 is probably right. with the amount of stuff you have to take off to even get to the timing belt to look at it, its probably worth going in and doing the job right and replacing everything.
> 
> Its just annoying when Audi should do the job right in the first place. :x They think its acceptable to replace half the timing belt components yet i bet if i went to my local garage they would advise me to replace everything.
> 
> Its times like this i wish i had no mechanical knowledge, it would be so much nicer being worry free from everything. Well, until the timing belt snapped and i had to buy a new engine!


Audi think from the manual stand point, they don't care and they're not thinking from practical stand point. As I said, I did all the components on my car and for now, knock on wood, it goes without a flow. You did a lot of mileage on the pump, it can go any moment now, also did some mileage on the other parts. as I said, I 've talked to dayco and they said that. You'll replace one or two parts, the other ones will have mileage on them and you'll be worried. it's a thing you're replacing, once every 5 years, for a £100 more I wouldn't bother the headache, as you wish... [smiley=thumbsup.gif]


----------



## pfgascoigne (Apr 7, 2011)

gunner,
The hydraulic tensioner does not tension the cam belt in the way many people assume. It provides tension for the "slack" side of the belt.
Think of a pedal bike. The upper part of the chain between the pedal sprocket and the wheel sprocket is always tight when you are pedalling. The lower part of the chain back to the pedal sprocket can be as slack as you want so long as you keep pedalling. Stop pedalling and a slack chain comes off. The hydraulic tensioner is there to stop the slack side of the cam belt from flapping around, which would cause damage to the belt. It does not provide tension that would affect the cam timing.
You say that the tensioner can stick in whilst tensioning the cam belt. So oil pressure pushes the tensioner out and tensions the belt. It then sticks in the position and all of a sudden that position which has originally been set by the tensioner is too tight. You'll need to explain that one to me as well. It would be interesting to know why you think the tensioner would stick in the out position, the piston is well lubricated with a constant supply of engine oil.

Wireless
Are you are saying that every replacement cam belt failure is caused by the tensioner? My experience is that a lot of failures are caused by idiots who don't know how to fit a cam belt properly and damage them fitting them!

Hi Hoggy,
Owners are free to change whatever they like, whenever they like. If you want to spend an extra £75 on a tensioner and it gives you peace of mind, that's fine. 
Because its received wisdom on this forum to change the tensioner with the belt, some people become very worried about their car, and there is really nothing to worry about. Replacement cam belt fails, it must be the tensioner. This "expert" has seen this damage, and another "expert" has seen that damage, but VW/Audi have seen it all, and more. The basic fact is that VW/Audi don't think that it is necessary to change a tensioner that is showing no signs of wear. If anyone on this forum is arrogant enough or stupid enough to think that they know more about a VW/Audi engine than VW/Audi themselves, then tell me, I'll send out the men in the white coats.


----------



## wireless (Jan 24, 2012)

Hi pfgascoigne, I am just pointing out one of the causes as the rest of us are.
Failure can result from other things such as water pump seizing, tentioner, roller guide but it all depends on if they have been replaced when the belt was done previously or not!.

I told a young lad that his water pump was on its way out as you can hear the rumbling from it which was why he came to me with his 1.8 Golf Turbo, he didn't like the price I had given as I told him that I would need to replace the T-belt as a kit and the water pump so he left and a few days later I had a call from the lad who told me his car failed on driving and he needed a tow to the garage.

This was when I found the the water pump had literally seized up and torn the belt apart which also caused serious damage to the engine ie valves had bent so in the end, he needed a cylinder head overhall.

Anything is possible!.

Thank you

Ps no one is telling you what you should or shouldn't do when getting your car parts replaced as its as you say piece of mind that you will have safe driving without the headahce of worrying that something may go wrong!.

Audi/VAG are no one special as with any other dealership and the mechanics or tech's working are just the same as any normal garage worker with a little more knowledge as they have the master computer system to guide them though their work.
Audi or any other dealer will not help you once something has gone wrong unless you have a nice credit card to flash at them :wink:


----------



## Hoggy (May 8, 2002)

Hi pfgascoigne, You keep stating the tensioner does not tension the cam belt, of course it does. The timing between crank & cams is *fixed* because of the number of teeth on belt between the crank pully & the cam pully & the fixed positioning of the pullys in the process. The other side, the slack side as you call it is kept in correct tension by the hydraulic tensioner.Without the tensioner performing correctly, the teeth will jump the pullys or strip the teeth from belt.
Every one can replace as much or as little as they like, most of us believe its more economical to replace all at once. 
Hoggy.


----------



## TT-TOM (Feb 15, 2012)

On another note..... Just had a look at the invoice for the cambelt work on my Audi and theres no mention of the engine mount stretch bolts. TBH I can think of plenty of times where Autodata or Haynes manual has said to replace bolts like on calipers and its never come back to bite me.


----------



## corradoman (Sep 11, 2010)

My local dealer laughed at me when i asked them for the hydraulic tensioner as a part of the kit saying they never replace them and brought a technician in to me who said they have never seen them fail and they laughed even more when i asked for the stretch bolts for the mountings! I told them it was my money!! I was naturally curious at what they told me and spoke to my brother who is a mercedes technician with 35 years experiance and he told me you can be lucky and the tensioner wont give up or unlucky and it will so just change it to be on the safe side he said but did say the bolts were going a little over the top! needless to say when i started the job and took the old tensioner off and set about retensioning it it started to leak and was shot! so good job i had bought the new one


----------



## gunner (May 18, 2002)

pfgascoigne, your comparison of a bike chain whilst peddaling and a cambelt with an engine under power is reasonable. This analogy shows that one side of the cambelt will be under tension whilst the engine is being driven. On the TT, since the engine rotates clockwise, its the right hand side (i.e. waterpump pulley side) which is tensioned. The left hand side may well be slack and this is why the tensioning damper needs to be there to take up any excess play. However, I wonder what happens when the engine is under deceleration? It may be that the left hand side of the belt then becomes tensioned and therefore the tensioning damper will have to allow for this.

By the way, I dont think the tensioning damper uses engine oil pressure to regulate itself. As far as I remember, its completley independant of the engine oil and as mentioned earlier is basically a spring loaded piston with built in oil damping.

I cant imagine why you wouldnt want to replace this, its not expensive and if you buy a complete cambelt kit from Conti or SKF (check eBay) its included anyway as well as the stretch bolts.

Heres a good picture of the cambelt mechanism










And another one of the tensioning damper itself, note the ring pull which must be pulled out after fitting to tension the belt


----------



## corradoman (Sep 11, 2010)

Correct the dampener is pressurised by oil and over time it seizes in one position as mine did and then it fails and leaks the oil and then is fooked and in turn leaks onto the belt contaminating it and then failure!! Change it simple :lol:


----------



## Hoggy (May 8, 2002)

Hi Gunner, thanks for the cam belt run pic, looked for one on Google last night & was unsuccessful. 
Hoggy.


----------



## gunner (May 18, 2002)

corradoman, no on the BAM 1.8 engine, the tensioner is not pressurised by engine oil !

As far as IM aware its completley independant of the engine oil, the tension is provided by a spring and there is internal oil damping to stop any harmonic vibrations.


----------



## corradoman (Sep 11, 2010)

gunner said:


> corradoman, no on the BAM 1.8 engine, the tensioner is not pressurised by engine oil !
> 
> As far as IM aware its completley independant of the engine oil, the tension is provided by a spring and there is internal oil damping to stop any harmonic vibrations.


Yes thats what i was saying


----------



## corradoman (Sep 11, 2010)

corradoman said:


> gunner said:
> 
> 
> > corradoman, no on the BAM 1.8 engine, the tensioner is not pressurised by engine oil !
> ...


its pressurised in the tube


----------



## John-H (Jul 13, 2005)

Oh dear cam belts again! It's an interesting subject, causes a lot of worry and a lot of damage when it fails, hence the worry.

The first thing I would say is that indeed Audi have changed their minds on the recommended mileage. They first, in common with other manufacturers were trying to reduce the service cost by asking the belt manufacturers to increase belt lifetime. This resulted in the 113k mile service requirement.

It's important to realise that failure is rare. The recommendations result from experiments on a number of samples run to destruction in accelerated lifetime tests. A statistical bell curve is produced which predicts the percentage failures against lifetime and a decision is made that 0.01% failures will happen beyond a certain mileage/years and this is set as the service period considering the number of warranty claims they are likely to have to handle set against the extra profit from sales due to the service period extension.

The trouble is that in accelerating a lifetime test certain assumptions need to be made and things can get overlooked. The water pump was one such example where the key factor was thermal expansion and contraction and ageing for a plastic that could only just cope with the operating conditions resulting in cracked impellers requiring a belt change.

Another overlooked factor was the bad publicity when people post on forums about their once in a blue moon cam belt failure and every concerned owner then decides to change early for peace of mind. This puts pressure back on dealers and the manufacturer resulting in the panic that not only are they going to get claims within warranty but also have to handle out of warranty claims as a "goodwill gesture" - this makes future customers happy that they will be looked after.

When the publicity started to rear it's ugly head the reaction was to reduce to 40k miles or four years whichever is sooner. Dealers started to send out these letters (a copy can still be provided) which helped the unfortunate few who had suffered failure to make a claim - "Look Audi know there it's a problem!"

We've seem a few cases of ~80k and even the odd 60k failure which has resulted- through our help - in the owners receiving a new engine from Audi free of charge aa gesture of goodwill.

That was a while ago though. Since then cars have got older and Audi have become less queued about the 0.01% "bell end" (curve!) failures, which It'd suggest is the reason why older cars still have a 113k mile service interval but newer ones are 75k - it's a breakpoint for; "Well your car is old sir" and the likelihood of you and others accepting this. Mere cars are more likely to be embarrassing.

So don't lose sight of the fact that this is a very rare event. People only post bad news on forums and warranty claim departments never heart about things that continue to work!

Having said all that I changed mine myself three times now, twice on my TT and once on the S3. The TT at 6 years amd then 50k miles, the S3 at about 60k it having perennially been changed at 80k. The first time on both cars the water pumps were cracked. The S3 was an original that had done 140k miles and it almost feel in two. Later Audi pumps are a current plastic that withstands a higher temperature and ageing - they do not need 22nd - hence my second water pump change on the TT was a waste of money.

The hydraulic damper was leaking at 120k on the S3 but only seepage and it still worked. I swapped it for the last one I changed on the TT which was as go od as new and also a premature change at 50k miles.

Incidentally, the damper can appear seized but in fact it is not - due to the oil damping, to compress the piston back in from the extended state you need to apply a sustained constant pressure for many many seconds in a vice. A quick press with your thumb and it hels as solid as a rock. Without oil inside it's am easy press press with your finger - this is a good way to test 

You can change too frequently and wear out your engine mount bolts. Mine failed the second time on the TT - well actually the alloy casting failed. As revealed in absolutte magazine, the design calculation for the thread strength shows it to be a marginal design. You'll find that the larger console to engine bracket bolts do NOT stretch - the casting does instead! The console to body bolts do stretch noticeably however.

I'm not going to mention camshaft oil seals


----------



## corradoman (Sep 11, 2010)

Great post john, and thats exactly what hapened to my tensioner i put it in the vice and gentle pressure then pop and the oil came out and at only 65k


----------



## John-H (Jul 13, 2005)

You didn't squash it too quick did you? Due to the fine clearances and the oil it only goes in very very slowly and you could easily develop tonnes of pressure if you tighten a vice too quick. If you expand the alloy casting it will effectvely burst past the piston. You know how you can crack a cylinder block if one of the block's cylinder head bolt holes has oil in it? :wink:

It took me several goes as it kept slipping out of the vice and I was convinced it had extended too far and got stuck like some Ford ones do. It just felt so solid and I was putting too much force on the vice handle for comfort - then I'd rest and the next time I tried it would fall out. I think it was slipping out when it went slack actually but I didn't realise.

Come to think of it now I think I eventually compressed it with a G-clamp with little pressure (the spring is only little) - slowness is the key.

I took the circlip out and took it all apart to see how it worked and there are two concentric bores in there and a one way valve with a spring and ball bearing. It works quite cleverly to keep an average spring pressure on the tensioner roller - it comes out slowly but goes back in super slowly. Very fine tolerances in there with no oil seals just metal pistons mean the oil is still held in place even if it were upside down in stores for years. Without oil the air can leak past and of course compress and then it becomes quite easy to push in.


----------



## corradoman (Sep 11, 2010)

John-H said:


> You didn't squash it too quick did you? Due to the fine clearances and the oil it only goes in very very slowly and you could easily develop tonnes of pressure if you tighten a vice too quick. If you expand the alloy casting it will effectvely burst past the piston. You know how you can crack a cylinder block if one of the block's cylinder head bolt holes has oil in it? :wink:
> 
> It took me several goes as it kept slipping out of the vice and I was convinced it had extended too far and got stuck like some Ford ones do. It just felt so solid and I was putting too much force on the vice handle for comfort - then I'd rest and the next time I tried it would fall out. I think it was slipping out when it went slack actually but I didn't realise.
> 
> ...


Ha Ha yes john i probably did overdo it with the vice but like yours it just wouldnt budge then all of a sudden bang :lol:


----------



## bobclive22 (Apr 5, 2010)

John-H,

Regarding water pump impeller,
I had mine changed at 36,000 on a 2005 car at 5 years, the impeller broke when being extracted, the intact part of the impeller was totally brittle, it broke in pieces with little effort.
We have just had a pump changed in an 04 at 72000, the impeller was in exactly the same condition as the 05, this indicates that a plastic impeller should not have been used by Audi, the cost difference of using a metal one must be peanuts.


----------



## John-H (Jul 13, 2005)

The original plastic impeller used to go brittle and crack that's true. A few years ago Audi changed the plastic to a much higher temperature grade type. These last so recently replaced ones shouldn't need replacement.


----------



## logan81 (Aug 3, 2012)

Sorry to bring up an old post but figured it was a better idea than starting a new one!

I've got a 52 plate with 62.5 k on the clock but not a great deal of history prior to 2010, other than the stamps in the book which go up to 2010, i dont have reciepts etc (i bought it from a chap who bought it as a certified used car from Audi in 2010). Dealers listed in the service book (including Audi) have been reluctant to give me invoices because of data protection (ie they will have the previous owners details on) but they have been helpful in answering specific questions and I am 99% sure the belt hasn't been done as a result. (As an aside, is it due to data protection that they dont pass on previous invoices etc after they have certified it as a used car?)

I've spoken to Audi directly and just like is said here they have said that while it does say 115k in the book, they would reccomend i change it.

Anyway i've got a price of £429 and the girl i spoke to said this was the belt and tensioner and also the v-belt, which seems a good price to me? However I read this thread from top to bottom (and some others) before I rang them and it's not really in line with other comments raised...so I would appreciate some input

I asked about water pump and mentioned a few other minor issues and they have offered a free health check (and are throwing in a courtesy car for the day!) to confirm any other bits and bobs that may need doing, so I have booked it in

Any advice appreciated 

Cheers


----------



## Hoggy (May 8, 2002)

Hi Logan, 5 years or 75k miles is Audi recommendation,which ever comes first. TTF recommends 5 year or 65k miles which ever comes first.
The Audi kit contains a tensioner, but that is just a roller, you also need to replace Hydraulic tensioner/damper which is extra cost. Replace water pump at the same time, extra cost again. 
Hoggy.


----------



## DuTTchNL (Sep 18, 2010)

Change it! I bought mine with a snapped belt.

It snapped way to early


----------

