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Has anyone cleaned their valves? (Carbon Build Up)

18889 Views 22 Replies 15 Participants Last post by  MrAl
The dealer recommended the service but I wasn't familiar with their methodology. My service rep wasn't there so I didn't get to talk to them. I know the consequence of direct injection is more carbon build up, but was wondering if anyone has done anything to clean their valves?
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I plan on doing an intake valve cleaning, at the same time I strap on my Trifecta supercharger kit..

How many miles do you have on your car ??
I plan on doing an intake valve cleaning, at the same time I strap on my Trifecta supercharger kit..

How many miles do you have on your car ??
35K, I'm sure there isn't a lot of build up yet but not sure how they get cleaned without pulling the heads.
they typically clean it through the intake or they clean it through the vacuum line for your brake booster. Im assuming they probably use GM top engine cleaner.
35K, I'm sure there isn't a lot of build up yet but not sure how they get cleaned without pulling the heads.
This is how you clean the engine without pulling the heads:

http://www.gixxer.com/forums/showthread.php?t=164315
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Since the 3.6 engine has been around for a long time and in many different models, is there decent history that shows the extent of the problem?

Assuming he is planning on using some type of solvent sucked through the intake, do you know what it is and if there is information (someone besides the manufacturer) that is works? What does it cost? I would want to understand what would be done and with what product before paying for it.

There's a lot of them on the market but not sure how well they actually work. Good news for them is you use it and really don't have any idea if it worked -

Thought this is an interesting article from 2011. I have no idea if it is right or wrong, just posting research. If anything, I would assume the current engine has gotten better - http://www.edmunds.com/autoobserver-archive/2011/06/direct-injection-fouls-some-early-adopters.html

All Engines Not Designed Equally
Many automakers’ gasoline DI engines do not appear to exhibit any carbon build-up issues at all, however. Digging into online threads about Cadillac’s 3.6-liter DI V6 in its popular CTS lineup does reveal some owner concerns about carbon build-up, but it’s difficult to find even a single report that any build-up has actually occurred – a record that is notable considering that Cadillac has sold more than 200,000 CTS models with DI V6s (Audi sold fewer than 2,000 RS 4s in the US during its two-year sales run).

Haider, GM’s V6 assistant chief engineer, explained how GM has designed its DI engines to combat carbon buildup: “We maintain great engine function and performance in our all our DI engines through an optimization strategy with our valve events,” he said. “Our intake-cam timing, injector targeting and timing of the injection events are optimized to avoid direct fuel contact on the intake valves. This strategy keeps smoke and soot formation to an absolute minimum, which in turn prevents excessive deposit formation.”

For instance, Audi’s new 3-liter supercharged V6, used in the S4 and A6 models, has so far been free from carbon-related complaints – a far cry from the 3.2 liter V6, which has numerous threads dedicated to the condition.

If Ford and GM engineers and Chick are correct, the carbon-buildup problem now may be relegated to previous engine designs that were not well-adapted for DI. But that’s probably little consolation to some early adopters like Boyadjiev, who must add regular carbon cleaning services to their cars’ ongoing maintenance requirements – a cost that, for now at least, they are expected to absorb entirely on their own as they grapple with the “dirty” secret of this emerging technology.
The BMW guys use a walnut blaster. Google bmw intake valve cleaning and it will pop up.

If the CRC stuff works, that would be great.
To tell you the truth, to me, this stuff is no better than snake oil unless I can see "real" proof that it does what it is supposed to do. And by proof I mean independent testing that visually shows before and after results with a turbo engine. I get the same "I doubt you until you can show me" feeling as I do when I can't find any real proof the K/N filters or nitrogen in street tires do anything beyond standard equipment.
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I've had the BG service performed on other cars (around 70k) and had noticeable results. There are also some before and after videos on you tube that are impressive. I just don't know how early it should be done on the DI engine. I use mostly top tier and run a tank with Tecron every 3 to 5k. Confident injectors are clean but its the valves I'm concerned about.
I doubt the chemical treatments work, especially if you use it after the buildup is significant. Take a look at this video to see just how nasty the buildup can get. You need some abrasive, like Ragtop99 mentioned, walnut shells are frequently used for this.

https://youtu.be/4Pd2aYxW-QM?t=23m41s
I doubt the chemical treatments work, especially if you use it after the buildup is significant. Take a look at this video to see just how nasty the buildup can get. You need some abrasive, like Ragtop99 mentioned, walnut shells are frequently used for this.

https://youtu.be/4Pd2aYxW-QM?t=23m41s
I had the 2.0T in my 2006 A3 (I am not as familiar with Tiguan but I believe same engine as in the video), had the valves manually cleaned by Audi at about 120k miles. The 2.0T in the 2006-2008.5's VW/Audi's had a lot of problems with buildup. Later VW/Audi 2.0T don't seem to have as much of a problem with it.

I am not going to worry about it unless I see more proof (anyone??) that it is a problem on this engine.
I had the 2.0T in my 2006 A3 (I am not as familiar with Tiguan but I believe same engine as in the video), had the valves manually cleaned by Audi at about 120k miles. The 2.0T in the 2006-2008.5's VW/Audi's had a lot of problems with buildup. Later VW/Audi 2.0T don't seem to have as much of a problem with it.

I am not going to worry about it unless I see more proof (anyone??) that it is a problem on this engine.
I'm pretty much on the same page. Some early DI engines (Audis come to mind) had problems with buildup, but since then, automakers have been well aware of the issue and have taken steps to prevent it. I'm fairly confident that on our 2.0T motors GM has worked hard to address it by addressing things like injection timing to help reduce the possibility of buildup. GM has produced millions of DI engines in the past few years (mainly 3.6 and the new V8s) and I haven't heard much of on this issue so far. Not worth the mental energy to worry so far.
G
Plenty of documented proof with the 3.6 by the Rx guy in the 2nd gen CTS forum with pictures.
Me I had an big fight with GM with my GM 2.4 Ecotec that had multiple misfires and dealers couldnt figure out how to fix it, My b.f. was a Gm tech for 11 years he used a scope to prove the valves were gunked up which forced them to change the cylinder head.

He said when the GM direct injection engines would come with Misfires with certain codes they would pull the intake and ect, soak each valve while closed and then clean it, vacuum it out,
Turn the engine by hand until the next closed and repeat.
My friends 3.6 DI Camaro with 36k just threw the dreaded codes and they did the soak just as CTSCHICK described.
With the hundreds of thousands of DI 3.6's they have produced over the years (maybe millions?) if this is a widespread problem they should be lined up being fixed. I think dealers would have a hard time keeping up with the problem considering how many different cars have used the 3.6 (throw in all DI engines and they would be fixing them them like the production lines the engines are coming off on). Someone reporting they know someone that had this problem isn't the same as it being likely to be a problem for me.

With my 2.0T (tuned) it eventually started to stutter under full throttle at about 4-5k rpm.

Edit: Wasn't clear, my 2.0T was my Audi A3 mentioned above and stuttering was valve deposits.
My 2012 SRX with the 3.6L engine needed cleaning at 57000 miles because there was no compression in two cylinders (one of which actually had a broken valve spring). Engine ran really rough before cleaning.
The thread has been dead for 2.5 years.

The cleaning service is nothing more than a labor time cash cow for dealerships and Oil Doodles. If you're worried about "carboned valves" or other mythology, dump in a 20 oz. bottle of Chevron TECHRON with your next fuel fill and then habitually use a TopTier gasoline. (Google both names)

The DI engines do have a problem with oil vapor intrusion and, because there's no direct fuel mist washing the intake valves, tend to get dirty.
I had a first gen 3.6DI in my 2008 CTS and it had over 70K when I traded it in for the ATS in 2014. Fuel economy was identical to new, no perceived loss of power, and the engine operating/smoothness was fine.

Some DI engines definitely had an issue with buildup, notably several models from VW and BMW but GM was a little later to the market and did a pretty good job of addressing this potential problem in the engine design and refined it in the second gen and subsequent engines.

The same question has been asked on other GM forums and here is the response from the chief Corvette platform engineer about intake valve buildup with DI engines: https://www.corvetteforum.com/forums/ask-tadge/3687191-answered-di-impact-on-valves.html

And you will find plenty of vendors happy to sell you a catch can to solve what is a non-problem for the rest of us :)
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