Turbo Trouble

mccleveinator

Member
Joined
Dec 10, 2013
Location
West Haven, UT
TDI
2002 Jetta
I don't know if this is the right section for issues, so let me know if I need to post this elsewhere.
I have a 2002 Jetta with about 215k miles and I've had an increasing lack of power for the past few years. I got my timing belt replaced a few weeks ago and the mechanic told it was time for a new turbo. I bought a New VNT-15 and installed it ( it's a China made, the mechanic said he hasn't had issues with those yet). I spent all day installing this turbo only to find that the car behaves the SAME as before. I'm thinking it might be a different issue. So help me out.
Symptoms: when the car starts up and I drive down the street it feels like there's no power at all, I can put my foot on the floor in first gear and it slowly gets up to 15 mph, and at 3000 rpm the power suddenly kicks in (turbo delay or something?) after that it appears as though there is a semi-working turbo, but it still accelerates slow, and driving on the freeway is about as much fun as driving a school bus. I've had a few tdi's and I have no idea why this one is such a slug. I'm thinking maybe a vacuum issue? I don't know, any help is great. I'd love to avoid taking it to a shop.
No limp mode, no signs of smoke, check engine light only on because of my EGR delete and a faulty glow plug.
 
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Ol'Rattler

Top Post Dawg
Joined
Jul 3, 2007
Location
PNA
TDI
2006 BRM Jetta
Probably a boost control issue, not necessarily a bad turbo. Was there damage to the old turbo or was there any play in the compressor? Did anyone put vacuum to the VNT actuator to see if it moved the vane plate?

You should probably remove the Chinese turbo and throw it in the trash before it damages your engine. I have read here about some of Prothe's Chinese turbos puking oil past the bearing causing a runaway and destroying engines on first startup after instalation.
 

Nevada_TDI

Top Post Dawg
Joined
Aug 17, 2008
Location
Reno, sort of...
TDI
2001 Jetta TDI
Really appreciate the above posters point of view, but that isn't going to help your problem it's the new turbo acted like the old Turbo you have a vacuum issue going to the turbo. You might have a couple sections of a vacuum hose you might have a broken solenoid and or you might have a bad N75 valve.
 

Ol'Rattler

Top Post Dawg
Joined
Jul 3, 2007
Location
PNA
TDI
2006 BRM Jetta
Sure. but It will help the OP from having a runaway from a Chinese garbage turbo. I agree. more likely the OP's problem is a control issue and not necessarily the old turbo.

The OP putting a garbage turbo on his car will only compound the OP's problem because it will bring problems of it's own.
 
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UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
There's a sticky on diagnosing low power issues.

Really have to get VCDS on it to see what's happening. Also, get a new mechanic.
 

Nevada_TDI

Top Post Dawg
Joined
Aug 17, 2008
Location
Reno, sort of...
TDI
2001 Jetta TDI
Can we try to be more help here guys? I agree it is possible the turbo he now has may not have the life span of one not made in China, but busting his chops doesn't do a thing to help diagnose what the real problem is. Okay, so the first problem he has was a bad mechanic, lesson learned. Now let's direct him to where the answers to his questions are can we please?
I will admit I don't have much luck using the VCDS lookup, but will someone else please look in his general area in Utah for someone with VCDS?
 

martin33100

Veteran Member
Joined
Oct 13, 2015
Location
UK
TDI
VW T5 2.5
You could always temporally Tee a vac gauge into the turbo actuator hose to see if the actuator is getting a vacuum to close the VNT mechanism.
 

turbovan+tdi

Top Post Dawg
Joined
Mar 23, 2014
Location
Abbotsford, BC.
TDI
2003 TDI 2.0L ALH, auto, silver wagon, lowered, Colt stage 2 cam, ported head,205 injectors, 1756 turbo, Malone 2.0, 3" exhaust, 18" BBS RC GLI rims. 2004 blue GSW TDI, 5 speed, lowered, GLI BBS wheels painted black, Malone stage 2, Aerotur
Hook up a vacuum gauge and look for changing vacuum. Diagnosed a BRM today with no boost. Guy put the vacuum lines on wrong-no vacuum at actuator, of course. :p
Funny how it has boost now, :p
 

BamaB4S

Veteran Member
Joined
Oct 28, 2011
Location
AL
TDI
1996 Passat
Functionality of the N75 often degrades over time before failing completely. If yours is original it's probably time for a new one.
 

mccleveinator

Member
Joined
Dec 10, 2013
Location
West Haven, UT
TDI
2002 Jetta
Here's the update. The VAC out line of the N75 solenoid was only pulling 15 mmHg. I replaced all the lines and bumped that up to 18. I bought a new OEM N75 and installed that and now I'm up to 20. It's supposed to be >25. It's still behaving as I mentioned in the beginning. I'll check the lines again. I'm thinking I'll just follow the lines and measure the vac. pressure at each branch to see if I can find the drop.
The vacuum pump is pulling exactly 25 mmHg (measured from the hard plastic output line) I hear that is the MINIMUM, what is everyone else measuring right there?
 

Nevada_TDI

Top Post Dawg
Joined
Aug 17, 2008
Location
Reno, sort of...
TDI
2001 Jetta TDI
25" is the "recommended" amount of vacuum in the system.
Have you checked/replaced the check valve and the vacuum ball?
If you have 25" at the pump/brake connector you should have 25" all the way to the passenger side.
 

flee

Veteran Member
Joined
Sep 19, 2011
Location
Chatsworth, CA
TDI
2002 Jetta GLS wagon
Here's the update. The VAC out line of the N75 solenoid was only pulling 15 mmHg. I replaced all the lines and bumped that up to 18. I bought a new OEM N75 and installed that and now I'm up to 20. It's supposed to be >25. It's still behaving as I mentioned in the beginning. I'll check the lines again. I'm thinking I'll just follow the lines and measure the vac. pressure at each branch to see if I can find the drop.
The vacuum pump is pulling exactly 25 mmHg (measured from the hard plastic output line) I hear that is the MINIMUM, what is everyone else measuring right there?
You mean inHg, right?
 

mccleveinator

Member
Joined
Dec 10, 2013
Location
West Haven, UT
TDI
2002 Jetta
25" is the "recommended" amount of vacuum in the system.
Have you checked/replaced the check valve and the vacuum ball?
If you have 25" at the pump/brake connector you should have 25" all the way to the passenger side.
The check valve is good, how do I check the vacuum ball?
I keep getting the P0101 code too. I just cleaned my MAF, and I really don't want to buy a new one, but if there's a way I can confirm that is the issue then I'll do it. Should I rent a VCDS? The nearest shop that does work on tdi's is an hour away and I'd like to just solve this beast myself.
 

turbovan+tdi

Top Post Dawg
Joined
Mar 23, 2014
Location
Abbotsford, BC.
TDI
2003 TDI 2.0L ALH, auto, silver wagon, lowered, Colt stage 2 cam, ported head,205 injectors, 1756 turbo, Malone 2.0, 3" exhaust, 18" BBS RC GLI rims. 2004 blue GSW TDI, 5 speed, lowered, GLI BBS wheels painted black, Malone stage 2, Aerotur
Unplug it, if it drives better, then the MAF is done.
 

Nevada_TDI

Top Post Dawg
Joined
Aug 17, 2008
Location
Reno, sort of...
TDI
2001 Jetta TDI
I don't know if there is an electronics store near you, but if the MAF shows up bad,you can use the diode mod to see if it works well on your engine. Some people have great luck with this mod and some do not
 

mccleveinator

Member
Joined
Dec 10, 2013
Location
West Haven, UT
TDI
2002 Jetta
Unplug it, if it drives better, then the MAF is done.
Yep, that did it. Unplugged the MAF and there's no more lag upon startup. I took it out and cleaned it with the MAF cleaner but it didn't change a thing. It looks like I'll be buying a new one.
I'll report how it performs as soon as I get it installed.
 
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