2012 GTI Turbo noise / Oil leak and possible low boost

[Brett0712]

So, to make a long story short, I don't drive my GTI that often and have started hearing some strange sounds while under boost. Its a 2012 4dr autobahn 6spd that I bought new back in November of 2011 and have a total of 2936mi on it now.

When I bought the car (from what I can recall) the turbo was never too loud and most certainly didn't make the high pitch howling sound that I am now hearing. When I go WOT, especially in the lower gears, I've noticed that the turbo is much louder and I hear what almost sounds like a boost leak. But it is hard to isolate due to the damn wastegate rattle that the dealer refused to repair. So, today I decided to install the wastegate clip, and take it out to run some logs to see whats up. First off, not having that damn rattle is amazing. Literally took about 15sec to install.


So, I did a pull in 2nd gear from 1500rpm up to redline (6500rpm) and it doesn't seem to pull like it used to. When I got home, I checked out the log and the peak requested boost was only ~8.55psi ((1590mbar - atmospheric pressure)*0.0145 = 8.55psig) While the actual was about the same and settled down to around 6-7psi. So I decided to get under the car again and check the boost pipes and things of that nature for any leaks and came up with nothing. Everything was nice and tight. Next I figured I'd take a look at the DV and to my surprise, there is oil seeping from it. I am going to assume that this is not normal, correct? The car is always in my garage at night and i have NO oil spots on the floor so it cant be leaking that bad, but it still doesn't seem normal.

Notice the oil on the stainless line and on the DV bolts?

So I guess my questions are:

1: What should I be seeing for stock boost values? My searching has turned up a peak boost value of about 11psi. Is there a simple way of determining if I have a boost leak. (going to run some more boost logs)

2: The oil on the DV, is this ~normal? Should I take it out and check it out or just take the car to dealer telling them I have been noticing some oil spots on the ground?

I am going to take the car out again and do another pull and get some better values.

Thanks in advanced for any help!

[ViRtUaLheretic]

The oil you are seeing is from the PCV gases, you have a leak/tear in your DV and the PCV gases are coming out of said hole.
Replcae your DV with the latest Rev and you should be good to go

If you want to clean up the PCV gases you should install a Catch Can as well.

[Brett0712]

Isn't the Rev "C" diverter valve a piston type? I know that people prefer the Rev "D" as they are piston type as well, but is the "C" still susceptible to failure under stock conditions?

Either way, a DV leaking oil doesn't seem good. I have an appointment tomorrow morning at the dealer so we'll see what happens.

Thanks for your help!

[sfdxsm]

Your problems sound just like mine - including a rattle. Where did you snag that clip from? Also had my car in the dealership and they didn't find anything wrong.

I also believe my DV is failing only after 6000 miles but can't really figure it out. I'm just a little low on boost like you based on my logs.

Not a GLI but 2011 A3.

[90crvtec]

Actually, that oil is probably from your oil feeder line to the turbo. My GTI had a pinhole in the line and it had to be replaced, it was also right around 3,xxx miles if I recall. Several other MK6 owners have had this same problem.

Like me, it looks like you've caught it early enough that it probably hasn't done any damage. I would take the car into the dealer and specifically request that they look into the turbo oil feeder line because you suspect that it's leaking. I found the leak under my car while doing an oil change and it looked exactly like what you have posted in the pictures.

[Brett0712]

I bought the clip from ECS after taking my car to the dealer and having them refuse to install it. Technically there is nothing ~wrong with the car, it just rattles. VW put out a TSB for dealers to install a clip that elimates the rattle if a customer complains about it. Some dealers have no problem installing it, other wont do it.

Here is a huge thread about it: Wastegate Rattle

I believe the TSB number is: 2024061 and the part number is: 06J145220A

In regards to the oil leak, I took it to the dealer on saturday and they are replacing the DV. They had to order the part so it will get installed mid-week. The only reason I asked them to specifically look at the DV over the oil feed line is because it seems like I have a boost leak and it makes sense that oil seeping from the DV and a small loss of boost pressure would be a result of a failing DV. I didn't mention the boost leak or oil feed line because my local dealer is as soft as puppy poo after a rainstorm and I'd rather take things one step at a time instead of getting them all flustered and having them screw things up.

I will report back when they install the DV.

[90crvtec]

I hope they get you back up and running soon.

I would still keep an eye out on the oil leak after they replace the DV. That oil feeder line is naturally pressurized by the rest of the oil supply being pumped in the engine. In my case it was spraying a very fine oil mist all over the back of my engine. It was a huge fire hazard, I was lucky that I caught it early.

Strangely, my car had just been in for an unrelated warranty service at the dealer, and they didn't catch it! When I got the car home I got under the car and was double checking their warranty work and I found the leak! Seems like quality, attentive dealer service is hard to find.

[Brett0712]

That's the plan. I'm pretty anal about people working on my car so I usually inspect everything after the dealer touches it.

I try not to go into the dealer and tell them whats wrong with my car, but instead try to "steer" them in the right direction. They usually look at me like I'm an azzhole that's trying to tell them how to do their job; which is totally understandable.

But, thanks again for the advice and help. I shall keep an eye on it and report back once its been fixed. Or if it hasn't...

[GeoffB]

Did this fix the problem as i have the same problem with mine.

Thanks for any info and help

Geoff