Newby help with limp mode!

linsChaho

Member
Joined
Aug 16, 2021
Location
New York
TDI
101
I bought a 1997 Passat TDI wagon for $600. Test drove it & no issues but on the way home it went into limp mode. When I started the next day, issue was gone then came back on. I believe it has happened 3 times & all at freeway speeds. No check engine lights. The motor has 267k on it. Power on it when not acting up I am more than impressed with. I took my Edge 2 controller and plugged it into the TDI but it does not seem to read the boost and was no VW to select, just had to clic VidMate k "other". Not sure if there is an upda Mobdro te that can do more, I will look. The car had some motor work a little over 30k ago: Crankshaft, rod bearing set, crackshaft gear, front & rear seal, main bearing set, lower timing cover, clutch disc, release bearing, oil pan gasket, boot, connecting rod bolt, seal/flange, timing cover. There was some screws, bolts & lube too. The other thing is 5th gear is out. Where do I start on troubleshooting? I will buy a code reader if it helps. If so what would be a good one with out breaking the bank?
 
Last edited:

Mozambiquer

Vendor , w/Business number
Joined
Mar 21, 2015
Location
Versailles Missouri
TDI
1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI
I bought a 1997 Passat TDI wagon for $600. Test drove it & no issues but on the way home it went into limp mode. When I started the next day, issue was gone then came back on. I believe it has happened 3 times & all at freeway speeds. No check engine lights. The motor has 267k on it. Power on it when not acting up I am more than impressed with. I took my Edge 2 controller and plugged it into the TDI but it does not seem to read the boost and was no VW to select, just had to click "other". Not sure if there is an update that can do more, I will look. The car had some motor work a little over 30k ago: Crankshaft, rod bearing set, crackshaft gear, front & rear seal, main bearing set, lower timing cover, clutch disc, release bearing, oil pan gasket, boot, connecting rod bolt, seal/flange, timing cover. There was some screws, bolts & lube too. The other thing is 5th gear is out. Where do I start on troubleshooting? I will buy a code reader if it helps. If so what would be a good one with out breaking the bank?
Try over in the B4/Mk3 section, the B5 Passat TDIs were a completely different animal.
 

Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
Use / borrow VCDS, log and graph boost requested vs actual. Determine if you are under or over boosting.

Common items are boost vacuum (really pressure) hoses which fill with residual oil, weak N75 valves, and wastegate actuators which can also fill with oil. All of the above typically inhibit the wastegate, and will cause an overboost condition and limp mode. VCDS is the only way to know for sure.
 

Vince Waldon

Top Post Dawg
Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
Canadian Grizzly's low-power step-by-step (linked in my sig) is a good methodical guide to troubleshooting.

As posted above, for best/fastest results you'll want to track down VCDS for logging boost actual vs. requested.
 
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