Chemical cleaning for turbo vs removal?

AndyBees

Top Post Dawg
Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
You might contact Wallace now that it has been a few months. I wonder mainly about the seals, and potential corrosion on the shaft leading to seal issues.


The post you quoted is almost 14 years old (May, 2009). And, the guy (Archer) hasn't visited this forum since May, 2015.
 

Sting

Active member
Joined
Jan 20, 2004
I have no idea how any of you who did this got it done. I'm amazed and equally frustrated that I can't. The back nut on the exhaust side has some weird corrosion on it (of course it does 🙄) I could tell right away I won't get much purchase on it with the 12mm and I'm more likely than not to just end up rounding it out. The other two are fine (of course 🙄).

But seriously, how did you even turn a ratchet in there? There's barely any clearance if the CV shaft is still in. 🤷🏼‍♂️ I even put an extension on, which helped get the socket seated better, but turning the ratchet still seems really difficult, especially for the back nut.

So here's my situation... I did get an over boost code, but no CEL or limp mode. Power was down for that drive but next time I drove, things seemed normal.

Over the last couple days before I tried doing this, I put the 150L size of Powerservice in my fuel and a can of Seafoam into the fuel too. I've been driving it hard, keeping it in 2nd and 3rd (4th when my speed is high enough), generally driving her harder. No other apparent issues since. Power is back to where it was before.

Could this have been just a random thing? Since I honestly don't feel confident about doing the chemical cleaning as it is, what else could I do to help clear things up? More Italian tune up's? Anything else I can add on the fuel side (or otherwise) that could help? I'm well aware of NOT putting ANYTHING through the intake, so I know that's out.

I still have my EGR in... Anyway I can go through the pipe underneath? I'm reluctant due to the fact I'm not sure what that long cylinder part is made from, the rubber hoses, etc.

Some further advice would be appreciated. Thanks!
 

P2B

Top Post Dawg
Joined
Jan 11, 2006
Location
Toronto & Muskoka, Canada
TDI
2002 Jetta, 2003 Jetta, 2003 Jetta Wagon
So here's my situation... I did get an over boost code, but no CEL or limp mode. Power was down for that drive but next time I drove, things seemed normal.
Power was down because the ECU detected an overboost and triggered limp mode. Limp mode is reset when you cycle the ignition.

There are a number of reasons for an overboost code other than a sooted up VNT mechanism. Have you performed any diagnostics on the boost control system? Do you have VCDS and/or a vacuum pump?
 

Sting

Active member
Joined
Jan 20, 2004
No I haven't. Never had any kind issues before. I'm unsure how to proceed. I do have VCDS and I think you mean something like a Mittyvac?
 

P2B

Top Post Dawg
Joined
Jan 11, 2006
Location
Toronto & Muskoka, Canada
TDI
2002 Jetta, 2003 Jetta, 2003 Jetta Wagon
No I haven't. Never had any kind issues before. I'm unsure how to proceed. I do have VCDS and I think you mean something like a Mittyvac?
First step is to run the VCDS boost control test with engine idling as shown in this video. The VNT lever should cycle smoothly through it's full range of 3/4"


If this test reveals an issue, follow the steps in this thread:

 

Sting

Active member
Joined
Jan 20, 2004
Thank you, I'll try the test tomorrow.

I took her on a solid drive this afternoon, giving her a good uphill thrashing in 3rd and 4th gear. Haven't been able to recreate anything from the other day. 🤷🏼‍♂️

I also neglected to post my original code... (I did not get a CEL, BTW)

16618 - Boost Pressure Regulation
P0234 - 35-00 - limit exceeded (overboost condition).
 

Sting

Active member
Joined
Jan 20, 2004
Test complete. Looked good to me. I could see the movement in my mirror, looked to be about that 3/4" you mentioned.
 

Sting

Active member
Joined
Jan 20, 2004
Just cleaned my VNT17 by spraying Oven Cleaner through the EGR port of the exhaust manifold. Easier than taking the turbo off and apart when I have a bazillion more important things to be doing
I'm assuming you have the EGR deleted?

Although in my case, I think it was a one off. Things seem to be working fine now.

Just scanned with VCDS, overboost code gone (didn't delete it previously). I did notice the IQ was a touch low (around 2.8) from when I replaced the injector seals, so I bumped it back up with VCDS a bit to get it up to around 3.8.
 
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