6% fuel dillution 2008 GTI 2.0 FSI

[rodrigolara]

Hi guys. This is my first time posting,

I sent an oil sample to Blackstone. Everything turned out fine, except for 6% fuel dillution. I wanted to know what could be causing this, so I called Blackstone.

Since my car's ECU is upgraded, they said the fuel mappings might be programmed incorrectly. So I called Revo and they said they were certain that was not correct.

I called the dealership and their service advisor told be to call VW of America customer service...really? I'm under warranty but I don't know were to start...should I replace fuel pump, filter, injectors? Where could I start the process of elimination... Also, I had carbon build-up (cylinder misfire) before so I may be symptom of ongoing fuel problem. It seems like dealership doesn't really want to do any preventative maintenance, rather just wait until something goes wrong. What do you suggest I do?

Thanks for your help!

 

[greenjp]

Is the ECU upgrade a VW-sourced thing? Unless it's "approved" or whatever VW is going to tell you to take a hike on any engine related problems, whether you're still in the warranty or not.

I'd recommend sending your UOA results to Terry Dyson for a more comprehensive review & discussion of potential issues & solutions. It might seem expensive but if the alternative is a poor running car and/or throwing parts at it it would certainly be worth it.

jeff

 

[Quattro Pete]

Originally Posted By: greenjp
Is the ECU upgrade a VW-sourced thing? Unless it's "approved" or whatever VW is going to tell you to take a hike on any engine related problems, whether you're still in the warranty or not.

Yeah, don't even mention an aftermarket programming to your VW dealer. Return the car back to stock programming before you take it back to the dealer for any warranty work. Actually, it'd be interesting to see another UOA sample when running the stock programming to ensure it's not Revo's problem.

As it is, these engines tend to deliver higher than normal fuel dilution numbers on UOAs. With more aggressive programming that pumps more fuel through the injectors, this probably just gets even worse. Still, something is not right because I'm pretty sure we've seen other UOAs from chipped 2.0 FSI engines that did not have such high fuel content.

 

[rodrigolara]

Thanks for your input. I'm going to reset the programming and wait till my next oil change to see if there's improvement.

 

[Quattro Pete]

Also, what are your driving patterns? Do you do lots of short trips?

How long did you warm up/drive the car prior to drawing an oil sample?

 

[SubLGT]

How many miles on this car?

 

[Artem]

Originally Posted By: Quattro Pete
Actually, it'd be interesting to see another UOA sample when running the stock programming to ensure it's not Revo's problem.



I think the use of UOA is a GREAT way isolate the cause of this fuel issue. If by running the stock tune, the UOA shows no fuel, it will be clear that the MAP provided by the chip is flawed and causing the car to run rich.

 

[robertcope]

I would probably not change anything and run another sample. It isn't like Blackstone has never been wrong before or a sample been "off" before. One sample is hardly scientific.

robert

 

[rodrigolara]

You guys are very helpful. Thank you for all your responses. I think I will.

1. Flash my ECU to stock specifications.
2. Take another sample at my next oil change.

 

[addyguy]

Why post in the UOA section, if you are NOT going to post a UOA?

There is a section for 'general UOA questions'.

If you have a UOA report, post the numbers - yes, you've highlighted your concerns, but more concrete conclusions can be drawn the more info you supply.

 

[Jim Allen]

Also, if this is very recent, Blackstone may still have your sample and they will usually rerun it if you ask. The fuel test is a pretty straightforward one, however, and seldom wrong.

Custom tunes are often the cause of fuel dilution. But a bad injector can cause it too.

From what I understand VW is even more hyper sensitive to custom tunes than most OEs. For that reason, remove the tune before you show up at the dealer. Also, dealers will sometimes overwrite your custom tune if they are working on the car and you can't get it back. Most of the companies that do custom tunes will charge you something to get it back.

Also bear in mind that a custom tune isn't foolproof and the company that sells it is always going to assume it's not their problem... or at least try to pass it off that way.

 

[INDYMAC]

Originally Posted By: greenjp
Is the ECU upgrade a VW-sourced thing? Unless it's "approved" or whatever VW is going to tell you to take a hike on any engine related problems, whether you're still in the warranty or not.

I'd recommend sending your UOA results to Terry Dyson for a more comprehensive review & discussion of potential issues & solutions. It might seem expensive but if the alternative is a poor running car and/or throwing parts at it it would certainly be worth it.

jeff


I second sending a sample to Terry. He is becoming very familiar with the GTI now, since his new test mule is a 2011 GTI.

 

[vinu_neuro]

Cookie-cutter tunes almost always run on the rich side to be safe. Combine that with DI and this is the situation you end up with. I confidently predict that the next UOA will be normal for a DI engine.