Carbon Build-up at 26K Miles

I do not idle my car a lot. I spend relatively little time in stop-and-go traffic as I try to avoid Houston freeways during rush hour. I am definitely well below average in that area (especially for an urban dweller). My office is less than 10 minutes from my house. I do have to drive 25 miles downtown 2 or 3 times a week but it's usually at posted speeds.

darkorb said:

those are late oil changes!
5k miles then change

If your fully stock, it should be covered. My dads Audi got it at 70,000KM and it had carbon build up, dealer covered it.

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Seeing as VW recommends 10k mile (15k km) oil changes now ... his intervals are ok. I always recommend to do an oil change in between the regular interval, at 5k miles (or 7500-8000km).

Edit - Ask the dealer if they can have VW goodwill the cleaning for the carbon build-up.

Most of the carbon build-up is from the oil seepage at the valve stems. Catch cans will do absolutely nothing to prevent carbon build-up. They only keep your IC and piping clean of oil from blow-by gases.

And people have seen significant carbon build-up after 20k or 30k miles. It's the compromise for DI.

Double's Dub said:

This is extremely common for a direct injected engine. The only real option is to get it cleaned either yourself or through a reputable shop. Catch cans do nothing to avoid this problem. I just recently ran meth/water injection in my car, which cleans the vavle head and manifold, completely eradicating carbon build up. Although i did do this early, my car only has 7k miles on it

In sum, the only mod to give you piece of mind is meth/water injection, my kit cost me 300 clams and is a stage 1 Snow performance kit . And once again CATCH CANS DO NOTHING FOR OUR ENGINES!

i bought it from BSH
http://www.bshspeedshop.com/bshstore/

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Well this has opened my eyes. I haven't looked up catch cans in a long time, i just remember everyone swearing by them. But now that you say it, water/meth really does make way more sense than a catch can. The reason these engines are dirty is because there's no fuel or anything going through the intake runners. Water/meth takes care of that... genius! And you make better power from it too. Thank god i didn't blow money on a catch can. lol

haymest said:

My dealer just told me that I need to do a cleaning at 26K miles. When I asked why it was building up they said it was gas or driving conditions. I don't really buy that given that I have yet to see anyone who needed it this early. They claim it's so bad that it's causing misfirings on three cylinders. They are replacing the intake manifold under warranty.

I've always put 93 octane premium in the car from reputable gas stations. I drive aggressively but don't redline it with regularity. Anyone else have this come up so early? Any other theories (preferably warranty-related) that might cause carbon to build up so quickly? They want $800 to do the cleaning. Is that excessive?

Any input would be much appreciated.

Thanks,

Tom

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Have the dealership take pictures of the carbon! I would want to see it for myself. You wrote misfire on three cylinders. What is the link to the carbon build up? Are they implying the carbon build up is so bad that the intake valves no longer seat properly and you are getting backfires? Again, have them take pictures. And what was the deal with the intake manifold? Why are they replacing it under warranty? That is pretty major. Did it crack? Why? And gee, maybe that might cause a misfire too.

As an aside, gasoline has absolutely nothing to do with carbon build up on the topside of the intake valves. If that is the carbon buildup they mean, the dealership is talking out of its ass. Carbon build up on the top of the valves can ONLY be created by contaminants suspended in the “intake” air stream. The gasoline is directly injected into the cylinder. How would that affect anything in the manifold or ports? Most likely the carbon build up is from the PCV valve.

If by chance the carbon build up is genuinely this bad, that is a symptom of another problem. Does this mean you have excessive blow by? Are your rings bad? Are bad rings covered under warranty? Have them run a compression check. This whole thing smells fishy to me, unless of course you are Stage 1 or 2. That would explain excessive blow-by.


And on the subject of catch cans, I have a homemade one that cost a whopping $20 total (can, tubing, connectors, etc.) It works flawlessly. Each month I remove at least 4-5oz. of fluid. To me, that is a lot. I know several people here claim catch-cans do nothing, but common sense tells me that much oily fluid can only be bad for the car. Aside from EGR gas, which is not oily, what else could cause the carbon build up anyway? Cheap insurance.

I have not noticed any backfires or even performance issues. The reason I brought it in was that the Catalytic Converter warning light came on. They say that is why they are replacing the intake manifold.

Again, the car drives fine and I haven't noticed anything weird going on as far as performance or engine/exhaust sounds. I have noticed a lot of carbon buildup on the tailpipes, though - not sure that is related.

One other thought. Why $800 top clean the valves? Most of the cost to clean the valves is the labor to remove the intake manifold and get to the valves. But they are doing that already under a warranty claim to replace the manifold. Why charge you AGAIN for that labor? Can you say rip-off? At a floor rate of $120/hr, $800 equals 6.67 hours of labor…just to clean the valves? Maybe they should charge an extra hour of labor to clean the valves. Those guys sound like crooks.

Why on earth is everyone over-reacting? :iono:

The only question that applies to the OP, is why, on earth, would you pay out of pocket for something that is happening under warranty?

If it is indeed that bad, it should be covered. Demand it, nicely.

PS, 65k miles on my TSI, zero carbon issues. Drive it like you stole it, get it hot, and abuse it.

If possible, have them explain the link between the catalytic converter and a faulty intake manifold. And if something is wrong with the manifold that adversely affects something as far downstream as the catalytic converter, who’s to say the manifold isn’t affecting everything else in between?

ClapperHighs said:

Well this has opened my eyes. I haven't looked up catch cans in a long time, i just remember everyone swearing by them. But now that you say it, water/meth really does make way more sense than a catch can. The reason these engines are dirty is because there's no fuel or anything going through the intake runners. Water/meth takes care of that... genius! And you make better power from it too. Thank god i didn't blow money on a catch can. lol

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Yea man, it works wonders. Not to mention that it cools your engine down DRASTICALLY! Twas, a reasonably simple DIY install, took me a few hours to get it in. I also have it controlled manually, and activate it when i need to. Its a cheap piece of mind indeed. Well worth the money:thumbup:

I haven't modded the car in any way other than tinting the windows and putting a Longhorn on the rear glass.

Wow.

Well, I know a catch can does nothing from all my research but W/M is the only other option to prevent it? I'm not willing to go that route with my car, personally.

That's the only other preventatives? I was planning on keeping this car for the long haul but that means facing this issue every 50k miles? I bought my car in March and already have 6k on it.. I drive a lot for work unfortunately.

NOLA-Ron said:

Wow.

Well, I know a catch can does nothing from all my research but W/M is the only other option to prevent it? I'm not willing to go that route with my car, personally.

That's the only other preventatives? I was planning on keeping this car for the long haul but that means facing this issue every 50k miles? I bought my car in March and already have 6k on it.. I drive a lot for work unfortunately.

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Blasting the valves should cost something like $400. Depending on your mileage you shouldn't have to do this more often than say every 4 to 6 years.
It's still cheaper than a DSG service.

Baldeagle said:

One other thought. Why $800 top clean the valves? Most of the cost to clean the valves is the labor to remove the intake manifold and get to the valves. But they are doing that already under a warranty claim to replace the manifold. Why charge you AGAIN for that labor? Can you say rip-off? At a floor rate of $120/hr, $800 equals 6.67 hours of labor…just to clean the valves? Maybe they should charge an extra hour of labor to clean the valves. Those guys sound like crooks.

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Excellent point. Notwithstanding that this should be under warranty, the cost over changing the manifold shouldn't be over $200.