Low power - Sometimes.

jimmy0000

Active member
Joined
Nov 23, 2006
Location
san francisco
TDI
2003 jetta
Hi All,


I have 2003 TDI, 274k miles, 5spd manual, there is no check engine light.



I have weird low power issue where sometimes when i start the car it might be at 25% power, barley able to idle, or run just fine.



If the engine power is low i will just pull over turn it off wait 5 seconds, turn the key on until the glow plug light goes off it normally then runs fine.



Recently its been happening more and more.



Any troubleshooting suggestions or info would be helpful.


Thank you
 

GlowBugTDI

Veteran Member
Joined
Jul 20, 2018
Location
Cambridge, MN
TDI
2001 Beetle GLS TDI (BIODSL). 01 original Glow Bug TDI (sold)
few things to check. 1 small boost leak causing limp mode. 2 failing MAF sensor. 3 clogged egr/intake (sounds to be least likely, but could check it out anyway sense your in there...).
i had the same thing happen in both of my cars 1 was the brake booster cable had a crack, and the 2nd was a bad maf sensor.
 

GlowBugTDI

Veteran Member
Joined
Jul 20, 2018
Location
Cambridge, MN
TDI
2001 Beetle GLS TDI (BIODSL). 01 original Glow Bug TDI (sold)
Perfect time to spend with family, and do maintenance!

Sent from my SAMSUNG-SM-G890A using Tapatalk
 

Vince Waldon

Top Post Dawg
Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
I'm going to take a contrary view and say that it doesn't sound like limp mode to me, if it's causing idling issues and happens right after you've started and before you're really asking the turbo to do anything.

My internet guess is EGR valve sticking partially open now and then. Cycling the power forces it to attempt to close, which it is able to do the second time.

In any event, a scan with a quality VW-specific scanner is probably a good starting place... turbo issues will be pretty evident.
 

jimmy0000

Active member
Joined
Nov 23, 2006
Location
san francisco
TDI
2003 jetta
Hi Vince,


I tend to agree, I haven't used my scanner because there is no check engine light (i assume no light = no codes). The EGR is $200 (non vw) I think I'll get a can of carb cleaner and see how that goes on helping the situation. I did replace all of the 3mm vacuum hoses, need to order some 5mm hoses and replace those next. Thanks to TDIJarHead for the limp mode post that had links to order vacuum hoses. (no change with the 3mm hoses updated).
 

Vince Waldon

Top Post Dawg
Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
A couple of further thoughts:

1) it's possible for there to be pending codes without the CEL being on, so a VCDS scan could still be helpful

2) since you have VCDS you can pretty quickly test your EGR to see if it's closing all the way every time

- physically remove the EGR (two hex bolts)
- clean it, if required
- reconnect its wiring harness and place it somewhere on top of the engine where you can easily see it
- after turning the key to "on", run the EGR output test using VCDS (right hand side of the Engine module screen, IIRC). The EGR will open and close, and you should be able to confirm that it closes all the way every time. You may want to shine a light on it while it's moving to confirm.

As the bushing wears or if it's jammed up with carbon etc it can jam the plunger slightly open, causing bypass airflow that hidden from the ECU and power/driveability issues.
 

jimmy0000

Active member
Joined
Nov 23, 2006
Location
san francisco
TDI
2003 jetta
It still has intermittent low power after EGR cleaning:



I removed and cleaned the EGR. It wasn't very dirty, the piston seems to be free and actuate with me pushing on it with a wood wire brush (which i used a little to clean the housing).



I am going to order 5mm ID vacuum hoses now.
 
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