# Cleaning carbon build up on my intake valves



## leonard_e36 (Sep 23, 2013)

Hello,
after i saw some horror stories about carbon build up and cam follower wear on the forums i have decided to give it a go and see how mines are showing.
the car have 78.000 miles on the clock and i bet it has never changed and cleaned these things.
the carbon build up was bad but not too horror, the part that has scared me was the cam follower which was bold. The anti friction material was all gone and it started scratching my cam. My mechanic told me that now it will wear out more quickly because of these scratches on the cam, so i will change it at every oil change.(not an expensive part just 25 pounds).
I also have to buy the o rings for the injectors as some of them came off with the intake manifold (12 pounds per injector because audi sell them only as a kit with other unnecessary bits).
What i can tell you after i've done this is that it gave me some peace of mind  at least.
I have the impression that the car is more responsive and accelerates a bit faster.
My mileage was 19 mpg (because i was so curious to floor it to see how it goes) but i'm sure it will be higher than before.


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## Templar (Mar 9, 2012)

Very interesting. Ive heard of this several times. It's been said that running the engine over 3000 rpm for min of 15 minutes a week can help reduce this. Suppose to go into a lean burn cleaning mode type of affair.


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## leonard_e36 (Sep 23, 2013)

Thats for the injectors only.
I drive 15 min on motorway at least twice a day , and very spirited city driving and it didn't helped the intake valves.

Now i saw how these modern cars are build to last only when they are under waranty. Neither dealer or "specialists" will tell you to do what i've done , or at least to change that cam follower , which can cause a lot of damage. Thanks that there are forums in the world


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## TT-driver (Sep 14, 2010)

Looks like a top job. Well done.

I'm still wondering though: If one would drive for half an hour or so on the motorway in 4th gear at 4500rpm, would the valves be cleaner afterwards? I can see the oil temperature going to 97-98 degrees C on mine when doing so. (normally just 88-90 degrees). The car also feels more alive afterwards.

I don't do any city driving and I avoid traffic jams by working 'off peak' hours. I spend around 30 minutes on the motorway @ 60mph. But I guess that kind of speed actually puts the engine to sleep.


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## leonard_e36 (Sep 23, 2013)

Like i said before i drive my car up and down M1 several times a day between 3000 and 5000 rpm each time for the past 10.000 miles and my valves were like you saw in the pics . 
This is happening because the back side of the valves are never touched by fuel (which have detergents in them) to wash them out. They are only touched by filtered air and recirculated gases from the crankcase. These gases (carbon) are a bit oily and stick to the metal very well in time. Basically it doesn't matter if you drive at 4000 rpm for 30 min because you don't have a denser substance to wash them out , only fresh air and recirculated carbon (which will be almost inexistent at that speed i'm assuming) , so what you do is only to minimize the carbon build up for 30 min .
On the other side, your injectors will be very happy .

With other words, you cannot clean the carbon build up once it's there , you can just prolong the amount of time in which this will build up by driving at high rpm's .

Don't forget to check/change your cam follower as well as it can cause a lot of damage.


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## TT-driver (Sep 14, 2010)

I wasn't familiar with you're driving style yet. When I was in the UK last month I thought the speed limits on the motorway were on the low side, so no clue as to what RPMs you were doing. 

I'm aware of the direct injection and its consequences. I don't think there is an EGR system as such on the BWA engine, but burned gases may make it on to the intake valves if the valve timings allow for that to happen. The rest could just be burned oil that lubricated the valve stems and indeed oil vapours. (the old catch can and will it help discussion)

My 'school of thought' was that perhaps by heating up the engine, the intake valves would get hot enough to burn clean. I don't know what temperature is required for that and if that temperature is achievable even though fresh air is flowing past them.

One thing is certain: clean injectors means less droplets of fuel and thus less partially burned fuel -> less sooth. Equally good spark plugs ensure optimal ignition. And clean exhaust gas sensors provide good info to the fuel system.

The cam follower is on the list of things to do. I know it's a part that is under a lot of stress and that the engine oil can't prevent wear.


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## Alexjh (Oct 10, 2012)

sorry 'm not reading.. what did you use to clean them? I mean if fluid like brake cleaner or petrol then doesn't all the crap fall into the engine?

so.. just wondering what process was for cleaning them up.

thanks!


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## Pippyrips (Jan 26, 2012)

That build up isn't that when compared to my old b7 RS4. My car was the first one MRC did a clean up job on. At 17k miles the build up was a lot worse. I think they still have the pics of what was inside on the mrc website in the development section.

It was done of the main reasons why I sold the car in the end, as well as a strong havering for a GTR


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## Templar (Mar 9, 2012)

Is carbon build up is a common issue with the TFSI engine how come we don't hear of many/any failures or running problems. 
Just a thought.


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## Essexaviator (Jan 10, 2012)

I am presuming VPOwer fuel won't help? I have run mine only on Shell Vpower from day one and its now on 24k
Steve


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## Jamie3184 (Sep 12, 2013)

Templar said:


> Is carbon build up is a common issue with the TFSI engine how come we don't hear of many/any failures or running problems.
> Just a thought.


I have heard of quite a few rough idle issues and misfires with the TFSI engine due to carbon build up, although that was in the VW Golf.


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## Jamie3184 (Sep 12, 2013)

Essexaviator said:


> I am presuming VPOwer fuel won't help? I have run mine only on Shell Vpower from day one and its now on 24k
> Steve


Not for the valves, the additives in the fuel won't help as they won't touch the valves or at least the outside of them.


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## Templar (Mar 9, 2012)

Jamie3184 said:


> Templar said:
> 
> 
> > Is carbon build up is a common issue with the TFSI engine how come we don't hear of many/any failures or running problems.
> ...


Similar engines so you would have thought similar problems. I did come across an interesting art on this a little while back, will see if I can dig it out again. Pretty sure it was related to the burning of oil.


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## Jamie3184 (Sep 12, 2013)

Templar said:


> Jamie3184 said:
> 
> 
> > Templar said:
> ...


Similar engines so you would have thought similar problems. I did come across an interesting art on this a little while back, will see if I can dig it out again. Pretty sure it was *related to the burning of oil.[/*quote]

That would make sense as people have swapped from the PCV system to a catch can system.


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## suffeks (Jun 16, 2010)

its getting better, rs4 FSI was the worst, the newer TFSI's are better, they run oil at 100C instead of 90C which helps, also make sure you use 504/507 oil, NOT 502 spec. the latest 1.8TFSI fixed the problem for good, as they put back a port injector which fires from time to time

i like autobahn runs, nothing beats 7k @ 300kph for 10 miles straight lol oil gets up to 128C i def burn all that shit out


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## Templar (Mar 9, 2012)

suffeks said:


> i like autobahn runs, nothing beats 7k @ 300kph for 10 miles straight lol oil gets up to 128C i def burn all that shit out


Chance would be a fine thing. :wink:


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## tti608 (Sep 4, 2013)

leonard_e36 said:


> Thats for the injectors only.
> I drive 15 min on motorway at least twice a day , and very spirited city driving and it didn't helped the intake valves.
> 
> Now i saw how these modern cars are build to last only when they are under waranty. Neither dealer or "specialists" will tell you to do what i've done , or at least to change that cam follower , which can cause a lot of damage. Thanks that there are forums in the world


Very interesting read as my TT has similar mileage and truth be told I wanted to get the cam follower checked out having never seen it changed on the service history.

- Did you do all this work yourself or take it to a garage? 
- What products did you use to clean up the valves or was it done by a garage/specialist?

Nick


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## leonard_e36 (Sep 23, 2013)

Alexjh said:


> sorry 'm not reading.. what did you use to clean them? I mean if fluid like brake cleaner or petrol then doesn't all the crap fall into the engine?
> 
> so.. just wondering what process was for cleaning them up.
> 
> thanks!


i used carb cleaner from euro car parts (3 pcs). Its like a spray.
You have to make sure the valves are properly closed.(2 or max 3 will be closed at a time and 1 will be open).
In worst case scenario you will get some carb cleaner inside which will burn off as it is pretty much like petrol . No chances for other stuff to get in.


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## leonard_e36 (Sep 23, 2013)

suffeks said:


> its getting better, rs4 FSI was the worst, the newer TFSI's are better, they run oil at 100C instead of 90C which helps, also make sure you use 504/507 oil, NOT 502 spec. the latest 1.8TFSI fixed the problem for good, as they put back a port injector which fires from time to time
> 
> i like autobahn runs, nothing beats 7k @ 300kph for 10 miles straight lol oil gets up to 128C i def burn all that shit out


128 degrees is a lot , if you have a look into GTR forums , Nissan is claiming that you have to change the oil almost imediately if it gets over 120 or 130 degrees (i dont remember exactly) and also about the gear box oil. I'm wondering if Nissan is the only manufacturer who is aware that his customers will drive the GTR like they stole it and admit that they have to take special care of the car/oils because of it, or is GTR such a special car and is more "sensible". (needs only fresh oils, not burnt off over a certain temp).


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## leonard_e36 (Sep 23, 2013)

npm108 said:


> leonard_e36 said:
> 
> 
> > Thats for the injectors only.
> ...


Hi, i have a friend who is a good mechanic (not a specialist) and i did this job with him. I used carburetor cleaner from euro car parts. 
I hate going to dealers/specialists as they don't let you see what they are doing and on top of that you pay a lot of money, don't learn anything and you are not sure if they did a good job or not as well.


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## Jamie3184 (Sep 12, 2013)

npm108 said:


> leonard_e36 said:
> 
> 
> > Thats for the injectors only.
> ...


If you don't want to take the car apart and clean it yourself you could use Seafoam or take it to a terraclean dealer.

I have never used either so can't say how effective they are.


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## Templar (Mar 9, 2012)

I remember seeing Terraclean used on Wheeler Dealer sometime back on Jag. Wonder if its really that effective at cleaning out the combustion system. Could be quite a find for our carbon prone TFSI engines.


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## leonard_e36 (Sep 23, 2013)

Lets suppose these products work , where do you think all that crap will go?


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## Templar (Mar 9, 2012)

Dissolved, burnt and blown out of the exhaust I imagine.


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## tti608 (Sep 4, 2013)

Thanks for the info Leonard. I'm like you....I like to watch but most garages don't allow it.


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## leonard_e36 (Sep 23, 2013)

Templar said:


> Dissolved, burnt and blown out of the exhaust I imagine.


Not so simple , carbon build up is like charcoal , cannot be burned again  . I left the carb cleaner to sit there for around 1 hour and i hardly could scrub that shit out with a metal brush, this shows how hard is to "dissolve" it.
if a piece of it detaches for example , it doesn't have time to fall into the cylinder because of the fast movement of the valves , it will probably get stuck and will not let one of the valves to close, then the piston will hit that valve .

What i'm trying to say is that there is no method to get that crap out of there safely , only to wash it and take it out with your hand .


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## leonard_e36 (Sep 23, 2013)

npm108 said:


> Thanks for the info Leonard. I'm like you....I like to watch but most garages don't allow it.


This is why is good to have a mechanic friend


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## Templar (Mar 9, 2012)

leonard_e36 said:


> Templar said:
> 
> 
> > Dissolved, burnt and blown out of the exhaust I imagine.
> ...


valid argument I agree. Still believe that there is more to this new system that is not immediately obvious. Will see if I can find more out but on the face of it I can see where you're coming from.


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