# Loss of turbo power



## simon_h (Jul 31, 2007)

My tt has been running fine since I bought it in September this year...... until today 

Driving home from work today I was experiencing a loss of turbo power. Everything is fine up to 3000 rpm but when I accelerate the revs spin up really quickly but with no power.

Checked the hoses (in the dark) when I got home and everything seems to be okay. Any thoughts?

I don't do too much tinkering under the bonnet, so an idiots guide as to what to check would be appreciated.

Thx.


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## .s3steve (Jun 21, 2007)

get someone with vag-com to scan your car!


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## audi975 (May 6, 2007)

simon_h said:


> My tt has been running fine since I bought it in September this year...... until today
> 
> Driving home from work today I was experiencing a loss of turbo power. Everything is fine up to 3000 rpm but when I accelerate the revs spin up really quickly but with no power.
> 
> ...


Sounds like the clutch is fooked!!


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## mattyR (Sep 14, 2006)

My first thought was clutch....especially since you say the rev's are rising really fast but no power


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## simon_h (Jul 31, 2007)

D'oh! Sounds expensive


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## acmurray (Jun 28, 2007)

If you want to test the clutch put it in first, pull the hand brake and try to drive off with the clutch fully engaged. If the car digs in and the engine nearly dies the clutch is fine. 
Could also be an inter cooler pipe that has blown off, gives the same effect you describe. :wink:


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## simon_h (Jul 31, 2007)

** Update **

Drove my TT for the first time this morning since my 'loss of turbo power' and the problem was not there! If anything, the delivery of power when the tubro kicks in seems a lot smoother :?

I will have a decent dual carriage run on my way home so I will be able to see if the problem has completely gone or is intermittent.


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## simon_h (Jul 31, 2007)

** Update 2 **

Well the drive home was interesting. My car performed fine most of the time except for the odd occasion when the revs raced up again.

Hopefully the fact that my fault is intermittent means that it is not the clutch but I now need ideas of what to check next.

I should have a couple of spare hours tomorrow so I will crack out my unused vagcom cable to see if that sheds any light. Is it possible that I have an intercooler hose that is collasping intermittently?


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## simon_h (Jul 31, 2007)

** Update 3 **

I now have no (or at least very little) boost  Not good but at least it should be easier to diagnose.

My plan of action is as follows;

1) Run a VAGCOM check (if I can get it to work!) to check for error codes.
2) Check hoses and clips.
3) Clean the MAF.
4) Clean the N75?

Is there anything that I have missed?


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## Wak (May 6, 2002)

simon_h said:


> ** Update 2 **
> 
> Well the drive home was interesting. My car performed fine most of the time except for the odd occasion when the revs raced up again.


if you have definitely not put any pressure on the clutch pedal and are in gear accelerating then a symptom like this sounds like a clutch or flywheel. :?

If it mostly occurs in the 3000-4000 rev band or in high gears on pressing the throttle to accelerate?

Peak torque is usually around 3200 mark on a 225


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## chrishTT (May 14, 2006)

has your car been mapped?


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## simon_h (Jul 31, 2007)

No I don't have a remap. I think that my 'racing revs' symptom have have been a red herring. I think that possibly the revs were rising at the normal rate but as there was no boost the increased revs were more noticeable. My plan is still vagcom (awaiting registration code) followed by cleaning of the MAF and checking the hoses.


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## simon_h (Jul 31, 2007)

** Update 4 ** - For those who are interested

Ran vagcom 'auto checks' and no faults were found. Cleaned maf (those screws are a bugger to get to with the arb in the way!) and checked hoses. Issues still persist.....

Plan is now to go for a drive with my laptop plugged in and log groups 115 (boost), 118 (N75) and 120 (torque) as suggested on Wak's website.


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## mlingram (Jan 28, 2005)

Simon,

Spooky, I just logged-in today to find out more about this becuse my car
is also showing the same symptoms and saw this thread.

I've had the symptoms since this cold-snap has hit the country (
purely co-incidental I guess)
Some days the turbo cuts-in (mine been re-mapped so you can easily
hear the Turbo when spooling-up) but other days you accelerate and
the car simply acts like a normally-aspirated car ?

Not sure what is causing this and havent as yet done any investigation
but will be interested to see how you get on.

The fact it's intermitted implies no Hoses can be loose. Could somehow
the ECU detect an issue and aviod using the turbo to protect the engine ?


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## ttmanz (Aug 21, 2007)

same thing happend to me last night & just what i was thinking it was! after speakin to wak & comfirmed!. phoned rac!! 45mins sorted!! number 2 coilpack!!


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## simon_h (Jul 31, 2007)

A coilpack failure should be pick up by vagcom though shouldn't it?


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## ttmanz (Aug 21, 2007)

not sure about vag-com :?


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## simon_h (Jul 31, 2007)

mlingram,

This certainly is a strange one. Like you my car runs perfectly smoothly now just with no turbo.

I will post my findings from my data logging runs but I may not get round to it until tomorrow night.


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## acmurray (Jun 28, 2007)

A dud coil wil not always show on Vagcom.


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## simon_h (Jul 31, 2007)

Would a faulty coilpack allow the car to run completely normally (i.e. not lumpy, no misfires) apart from the turbo?


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## ttmanz (Aug 21, 2007)

my car felt fine up to 3000 rev's then aftre 3000 was very lumpy splutering allover the place


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## mlingram (Jan 28, 2005)

Simon,

It does sound like we have the very same issue.

As with you, there is no hesitation when accelarating through the rev
range at all. It simply feels like the Turbo has been dis-connected.

Perfect timing with Xmas on top of us and me having just shelled out
for a Brake Fluid, Haldex oil & Filter change !!!

Matt


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## rico (Sep 25, 2006)

Guys,
This may sound strange, but i also have this problem. Car has been performing really well since the cold weather, turbo pulls hard and car goes really well.

When i start the car up the next day after a hard drive..... no turbo, my boost guage shows 5psi and wont go any higher. Turn the car off and on again, boost is back.... really strange. Have been getting an intermittent pressure lost between DV and induction, so vagcom says. But surely turbo would always be without boost if there was a leak. My car has a p-torque remap and a few other bits.

Rico


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## audi975 (May 6, 2007)

rico said:


> Guys,
> This may sound strange, but i also have this problem. Car has been performing really well since the cold weather, turbo pulls hard and car goes really well.
> 
> When i start the car up the next day after a hard drive..... no turbo, my boost guage shows 5psi and wont go any higher. Turn the car off and on again, boost is back.... really strange. Have been getting an intermittent pressure lost between DV and induction, so vagcom says. But surely turbo would always be without boost if there was a leak. My car has a p-torque remap and a few other bits.
> ...


I had EXACTLY THE SAME fault,!!!!!
Only happened since the Remap?? yes?!
Cure?? get rid of P-Torques map!!! got a REVO on mine and its never done it again. Will at P-Torque continued to deny that any of my problems could be due to the remap


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## simon_h (Jul 31, 2007)

Went out for a drive last night to log some vagcom data. I am finding it difficult to draw any conclusions from my data. I was logging groups 115 (Boost), 118 (N75) and 120 (Torque) on one run and 115, 118 and 003 (MAF) on another.

What is the best way to get good data to diagnose? Flat road, 4th gear, accelerating from below 3000 rpm to 6000?

What it the maximum pressure that I should see at the intercooler? The most that I have logged is 1770 mbar (approx 770 after removing atmospheris pressure).


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## Stav (Jan 7, 2007)

I'm no expert, but my understanding is that if it feels like you don't have a turbo you are in "soft limp mode" where the car has shut things down to prevent damage due to extreme engine conditions.

I recently had this and seemed to have particularly erratic boost pressures over 3,000 rpm, sometimes it would pull like a train and sometimes be flat as a pancake. For me it was down to a sticky N75 valve which was causing the turbo to go into an overboost situation and the ecu would push the car into limp mode to prevent any harm. I would imagine that this would be more pronounced on remapped cars as well. I've changed the N75 for Â£45 from vagparts and all is well with the world!

Although I didn't do it I understand that the way to test for this is to plot requested boost against actual boost on Vagcom.

Hope that helps


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## simon_h (Jul 31, 2007)

Apologies for posting data rather than graphs but I thought that this was quite interesting (to me anyway!) There seems to be a lack of boost request although the actual boost does increase :?

rpm req actual
2520	1030	1170
2960	1030	1190
3200	1030	1170
3360	1030	1170
3520	1030	1200
3680	1030	1210
4040	1030	1340
4440	1030	1300
4600	1030	1300
5080	1150	1430
5640	1060	1410
4160	1680	1590
4760	1650	1510
5160	1030	1430
5360	1030	1380
5560	1030	1380
5760	1030	1360


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## Naresh (Nov 22, 2004)

Those of you encountering problems recently can you tell us if you have a remap, and if so with who company? Maybe then we can see if this is an isolated incident a particular remap or perhaps a case or replacing the DV, N75 etc.


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## simon_h (Jul 31, 2007)

My TT is completely standard apart from cosmetics (although a new DV is on it;s way from Forge )


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## rico (Sep 25, 2006)

Naresh,
P-Torque remap,
AMD hyperboost DV,
Original N75.

Cheers
Rich


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## tiTTy (Feb 15, 2006)

Same problem:

Forge DV

No remap :?


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## cb (Feb 18, 2007)

same problem with and without all the mods.
had new maf sensors and coil packs spark plugs only thing i havnt changed yet is the n75.
also had a focus that did the same thing


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## cad monkey (Jun 13, 2007)

I have a similar problem. The car will drive like the turbo is not working at all, then next time i drive it you can feel the turbo kick in and it pulls like a train (well at TT really!)

Mine is a standard 225 (2002)


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## mlingram (Jan 28, 2005)

Same issue here :

P-Torque remap 
Forge DV
Original N75

Matt


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## simon_h (Jul 31, 2007)

cb said:


> same problem with and without all the mods.
> had new maf sensors and coil packs spark plugs only thing i havnt changed yet is the n75.
> also had a focus that did the same thing


My previous car was a focus and my turbo stopped working due to a faulty wiring loom. Had the loom repaired and everything was fine.

There seems to have been a large increase in boost problems since the weather has got colder. Surely this can't just be a coincidence.


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## cb (Feb 18, 2007)

simon_h said:


> cb said:
> 
> 
> > same problem with and without all the mods.
> ...


this was a non turbo focus with only a induction kit but every now and then it felt wrong


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## Stub (Mar 17, 2005)

hmmm strange, I am to having this issue, my car does this when not giving it full throttle, if I push it through the boost progressively sometimes say 40% of the time the boost is off and on like a yo yo, if I push it hard it pulls through it, I thought it was a coilpack or could be the maf so I had those changed, it is still there but to be fair the car feels better for the change, I am in at VAGTECH tomorrow getting a new N75 so fingers crossed it will fix it?

Just for a note my car should be pushing 290 ish now and the boost came on to max at 28 psi, now it will go to about 23 24 but when the juddering appears it feels very severe as it is trying to boost so hard?


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## audi975 (May 6, 2007)

Stub said:


> hmmm strange, I am to having this issue, my car does this when not giving it full throttle, if I push it through the boost progressively sometimes say 40% of the time the boost is off and on like a yo yo, if I push it hard it pulls through it, I thought it was a coilpack or could be the maf so I had those changed, it is still there but to be fair the car feels better for the change, I am in at VAGTECH tomorrow getting a new N75 so fingers crossed it will fix it?
> 
> Just for a note my car should be pushing 290 ish now and the boost came on to max at 28 psi, now it will go to about 23 24 but when the juddering appears it feels very severe as it is trying to boost so hard?


For me even a new N75 & a N279 valve, new DV, new MAF, new Coil packs etc etc did not cure this but after a REVO remap its never been there,


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## cb (Feb 18, 2007)

seems every body is having the same problem. have had the car for 2 years now starting to think it maybe the petrol. i dont put the same fuel in it every time . ECU has to adapt every time??


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## audi975 (May 6, 2007)

cb said:


> seems every body is having the same problem. have had the car for 2 years now starting to think it maybe the petrol. i dont put the same fuel in it every time . ECU has to adapt every time??


Cant be petrol, when it happens within the same tank of fuel m8.....


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## Stub (Mar 17, 2005)

Update on mine, ITS FIXED!!!!

Like I said for the last few months the drive has been getting worse, I thought that because I'm running such high boost that it meant that I could no longer drive it progressively through the gears as unless I slammed the accelerator and pushed it through to max boost it felt juddery and crap, pulling out from junctions onto traffic used to be fine, for the last few months it has been hit and miss, either it was dam quick and fine or it was all over the joint juddering and with big dry flat spots, Today I went back to VAGTECH Top guys there (and girls :wink: ) and they did my N75 and lamda sensor (or what ever its called) last week they changed the coil packs and the MAF but the issue was still there, the car felt much better from the coilpacks and MAF but still juddery, oh one thing the first round did was sort my POOOOR MPH, well after driving home tonight the car feels like a new beast, progressive, holds boost, feels strong all the way and all in smoother feel to the power!

I had KW2's, new back disks/ pads and new R32 ARBS as the old ones where creaking, I will write up when I get 5 about these other mods as they too have changed the car 

I was thinking about getting rid of it as it was pissin me off to drive, now Im soooo happy it feels great


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## Stub (Mar 17, 2005)

The issue I have stated in this thread is comin back 

I have changed everything so imâ€™ lost?

Another added issue is before I had the n75, coils, dv maf and other bits done to sort the issue the boost went up to over 25 and held at 25 for a while on overboost, now its only boosting to 25 quickly and then stays at 20 on over boost then drops off,

When I first had all these changes done it seemed fine again I could drive it up through the gears and it was smooth, I'm wondering if it may be the weather as it has turned a bit cold again? Maybe its my turbo on the way out? Maybe its extreme lag but why is it very intermittent?

The main symptom is when you accelerating on half throttle the boost starts a little then stops then starts and this can lead to a big dry patch all the way up to say 4k, if I plant the accelerator I can seem to pull through it but I donâ€™t want to plant my foot after every gear change?

Any Idea's


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## wrekTT (Jan 11, 2008)

Stub said:


> The issue I have stated in this thread is comin back
> 
> I have changed everything so imâ€™ lost?
> 
> ...


It sounds like the DV is not holding pressure and dumping it too early

If you have a Forge DV, try changing the spring in it to a yellow one if your car is remapped, which is slightly stronger, and hold the pressure better, these are available from Forge motorsport,


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## starski4578 (Aug 24, 2007)

Stub said:


> The issue I have stated in this thread is comin back
> 
> I have changed everything so imâ€™ lost?
> 
> ...


All i can say is my 180 had this prob in the end i just sold it as i couldnt get to the bottom of it and like u say it wasnt such an issue if u wanted to boot it. I changed MAF temp sensors cleaned the throttle body changed the dv but it wouldnt cure it. I was going to try spark plugs coil packs lambada probes etc but where do u draw the line! Thankfully ive never had this issue with my 225. Hope u get it sorted soon.


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## cb (Feb 18, 2007)

think iv solved the problem in my car at least. if i let it warm up until the revs drop below 10k every thing is ok. had this problem for so long now and all it took was to warm it up before driveing off
hope it help for every one else


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## Stub (Mar 17, 2005)

I travel 20 mins into work does this mean that I have to wait 10 mins every day before I can pull out at junctions with confidence it wont splutter?

Do people think If I got a hybrid turbo or somin it would solve it?

Maybe I could get her in the garage every night to help :!:


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## chrishTT (May 14, 2006)

ive go the same problem guys
when you put it on vag com what codes does it bring up?


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## Stub (Mar 17, 2005)

what remap have you got chris?

is it like the turbo wont spool smoothly but intermittently doing this?


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## chrishTT (May 14, 2006)

i have a p torque remap
its hesitant at about 3000 then pulls through change hesitation like this
too scared to put your foot down
just in case i go through the windscreen


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## Stub (Mar 17, 2005)

hmmm try and warm it up and then see if it does it?

I reset my throttle body today and will see if it does any good?


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## wrekTT (Jan 11, 2008)

chrishTT said:


> i have a p torque remap
> its hesitant at about 3000 then pulls through change hesitation like this
> too scared to put your foot down
> just in case i go through the windscreen


theres alot on here on TT's with power losses and although a relative newbie on here, a fair few are remapped with P torque and a couple of others


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## lloydie999 (Dec 15, 2007)

There are loads of cars in this thread that a not mapped and several that have different maps, the only common theme is they are all TT's :?

I know its a bit obvious but has anyone thought it could be a weak hose closing under the pressure but not actually splitting? or some other hard to recognise fault. Think everyone has come up with the usual answers, maybe someone should put their car on a rolling road to check it out properly. It seems like its a common probem and the cold has made it worse..........


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## chrishTT (May 14, 2006)

well vagcom has brought up a 17705 code

drove for about a mile or so and coils blew
before this the car was running fine pulling hard

it just hasnt been the same since this happenedput new coilsn plugs in oil and filter change

still nothing


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## Stub (Mar 17, 2005)

Chris do a throttle body reset, prob wont help but worth a go I did mine yesterday?


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## p-torque.co.uk (Sep 12, 2006)

wrekTT said:


> chrishTT said:
> 
> 
> > i have a p torque remap
> ...


No.....one guy was completely unfair, and jumped on every thread to bad mouth the P-Torque map. Do a search for 'P-Torque' and read our reviews :wink:

There over 100 members running the our map.

Chris has had our map for a year now, and it was perfect. What he is saying is that the engine has developed a hesitation


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## TTCool (Feb 7, 2005)

Who'd be in business? Thank God I'm retired. Mind you I had 47 years of it 

Joe


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## p-torque.co.uk (Sep 12, 2006)

TTCool said:


> Who'd be in business? Thank God I'm retired. Mind you I had 47 years of it
> 
> Joe


 :lol: :lol:

I know, it is wearing me out now :wink:


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## TTCool (Feb 7, 2005)

p-torque.co.uk said:


> TTCool said:
> 
> 
> > Who'd be in business? Thank God I'm retired. Mind you I had 47 years of it
> ...


Chin up. I didn't get where I am today without...etc etc

This is what I had printed on my P & L

"Semper in Excretia Sumus Solum Profundum Variat"
(roughly...Always in the shit, only the depth varies :lol: )

My accountant used to say " Don't let the Bar Stewards get you down, no offence intended or implied, but I know he only said that to ingratiate himself so that he could justify the huge bill he used to send me. MORE LAUGHTER :lol:

Joe

PS Do you now feel better on this miserable Sunday afternoon, weather wise that is?

PPS There's no charge for the therapy, unless you would like to give me a discount on a re-map. Stop there Joe before it's too late.


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## p-torque.co.uk (Sep 12, 2006)

Words of wisdom!

The weather does get everyone down I think! Its very miserable out there


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## luciferlee (Aug 3, 2005)

i too am suffering from "loss of boost" sometimes it feels like its pulling, most time it does not

I have Custom Code remap

its doin my head in

Wak changed my DV and MAF at time of remap beggining of 07'

:? :? :? :? :?


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## UK225 (May 12, 2002)

luciferlee said:


> i too am suffering from "loss of boost" sometimes it feels like its pulling, most time it does not
> 
> I have Custom Code remap
> 
> ...


Hi Lee,

The issue with your boost is not the 17705 "bug" most seem to be suffering from in this thread.

Your ECU hard/soft revision is not an affected variant.

You need to pop over for some diagnsotics I am sure it wont be hard to isolate what the problem actually is.

Cheers
Morgan


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## Stub (Mar 17, 2005)

Morgan can you PM me or put it here how much diagnostics will cost and how long it will take?


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## UK225 (May 12, 2002)

Stub said:


> Morgan can you PM me or put it here how much diagnostics will cost and how long it will take?


Hi Stu,

We charge Â£30 per hour for targetted diagnostics.

How long it takes to isolate is dependant on the exact fault/symptom.

PM me all your issues 

Thanks
Morgan


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## chrishTT (May 14, 2006)

ye done the throttle body reset
also took it off and gave a thorough clean


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## chrishTT (May 14, 2006)

so what could it be ive vaggd it and has come up with 17705
check dv between turbo and throttle bod

says symptoms are throttle bod dirty
or split hose


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## chrishTT (May 14, 2006)

anyone had anyluck with this problem in resolving it?


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## Colin240sport (Jan 17, 2008)

strange i picked up my 06 plate QS last saturday, and on a trip to newcastle 3 hours later it did this several times...then again the next day...but hasnt done it since

car is totally factory standard....where the boost should really be at its max from 3000-4500 there isnt any boost at all....back off a few times..it sorts itsself and then your away working fine again

gonna ring audi and get this N75 thingy doo dah changed under warranty first i think 

very very annoying problem when your playing with clio 172 cups at the time.... :roll:


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## chrishTT (May 14, 2006)

it is annoying had a megane at the side of me the other day and couldnt do much as i was hesitating at 3000rpm

going to change the dv spring and n75 also


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## chrishTT (May 14, 2006)

bringing this thread back as i still havnt solved it
ive come to the conclusion that i have the bug 
after changing everything
2xN75, MAF , new coilpacks plugs new hosing boost and vacuum, new PCV system, n249 many throttle body resets and cleans
ive contacted the tuner who was nice enough to say he would sort it FOC as im running his software
asked when i could bring to him no reply in week and half and 3 emails later nothing.

my symptoms are as ive read are exactly as the bug described
cold start 
17705 code under 5degrees
no spool up
hesitation

anyone have the same symtoms lately


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## roddy (Dec 25, 2008)

chrishTT said:


> bringing this thread back as i still havnt solved it
> ive come to the conclusion that i have the bug
> after changing everything
> 2xN75, MAF , new coilpacks plugs new hosing boost and vacuum, new PCV system, n249 many throttle body resets and cleans
> ...


i've been getting it for a year now and every time i get fed up enough to get it fixed ,,it sorts itself !!!!!!, must say i am a bit diss that the n75 has not sorted it, it thought it must be that on mine !!!


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## chrishTT (May 14, 2006)

roddy said:


> chrishTT said:
> 
> 
> > bringing this thread back as i still havnt solved it
> ...


is yours standard

whats your software coding?


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## roddy (Dec 25, 2008)

eh Chris,,,     ,, i dont know,, sometimes i think it has been mapped, ( it is very fast and revs very high ??? !!.   ) tho not by me .   and have only done a vag on it with no faults showing ,, tho have not managed to get vag while it has been playing up,,,    ,, ( hope less case !! )


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