05 passat problems

[bako]

having problems with the turbo overboosting when climbing a hill

[DeliveryValve]

What codes are you getting on the VCDS?


It could be a number of things like a bad N75, stuck VNT, leaking vacuum lines, etc.



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[bako]

have a problem when the car starts up a hill the check engine light comes on. scan it says turbo over boost then it goes into limp mode turn the key off reboot runs ok agian until you gas it hard anybody have any idel whats up

[Lug_Nut]

No, but I have exactly the same symptoms.
If I drive for 15 seconds or so (100 yards the other way and turn around) before trying the hill, no problem.
If I use tip mode and hold gear until 3k rpm, no problem.
If I try to brake-stand (foot on the brake AND hard accelerator pedal application) for about 5 seconds, then drive normally in full auto, no problem.
If the car has already been driven that day, no problem.
If I use full auto and WOT, no problem.
Let me know if you find any solution.

[bako]

The only code that came up was turbo over boost and the emission light comes on goes in to limp mode turn off restart runs ok.up a hill or hard acceleration it goes into limp mode.

[aja8888]

Are we sure it's not turbo underboost? Check vacuum lines and turbo hoses for leaks, etc.

[bako]

I try smoke test tomorrow

[bako]

Originally Posted by aja8888

Are we sure it's not turbo underboost? Check vacuum lines and turbo hoses for leaks, etc.

I will smoke test it tomorrow what vacuum line should I look at.

[aja8888]

Originally Posted by bako

I will smoke test it tomorrow what vacuum line should I look at.

The N75 valve is located at the front of the engine, passenger side under the air box inlet. Check the hoses there and the one that goes up from there to the turbo actuator.

[vwztips]

I have not had this problem on my Passat TDI but have had it with 1.8t's and it was definitely the N75 causing my non-chipped 1.8t to spike to chipped boost levels and then go into limp mode rather abruptly.

[Lug_Nut]

Here's the start of this request:
http://forums.tdiclub.com/showthread.php?t=329908


Replacing my N75 did not change my cold start, moderate hill within 30 seconds of start limp mode.
If the car idles for about 45 seconds before I attempt the hill, of if I floor it through 1, 2, and 3rd gear going up, or I use manual tip mode and delay shift to 3000 rpm, there is no limp. No, the N75 is not my culprit.


other posts of my identical problem:
using "limp" as the key word:

post #5 here: http://forums.tdiclub.com/showthread...highlight=limp

When I thought I had it fixed post #13 here: http://forums.tdiclub.com/showthread...highlight=limp

Still 'fixed' in post 27 and 33 here: http://forums.tdiclub.com/showthread...highlight=limp

and here in post #13: http://forums.tdiclub.com/showthread...highlight=limp

using "tip" as the key word:

post 2 here: http://forums.tdiclub.com/showthread...&highlight=tip

post 25: http://forums.tdiclub.com/showthread...&highlight=tip

posts 18 and 22 here: http://forums.tdiclub.com/showthread...&highlight=tip


Some of those make it look like the problem is solved? Nope. It was gone for a few months then came back.

[tlbo]

I too have the 'limp mode' syndrome, except mine will accelerate slow, then accelerate as normal, left in Drive it will sometimes take longer to go through the gears, if done in gear mode, does fine in the acceleration, for a hill, change to the gear mode, and let it climb naturally may loose 2-5 mph's. If you push toooo hard then it will go into 'limp mode'.....no fun turn on 4-ways so will not get run over...... Did ask VW dealer about the issue......shop foreman, tech, and instructor has NO idea on what would cause the issue except, a $1500 ECM (Electronic Control Module), that being a 50/50 chance THAT MIGHT FIX IT............ At first got the car back it would act like it was being starved of fuel......sucking air......fuel filter.......it then asked me to STOP at that time I did, so I could try again. Now it start every time, except for today twice it baulked - not as long as the other times - but started....Of course I did try to convince VW (Park Cities/Boardwalk) that something else was the issue.... I work on PC's just trying to show them (VW) on thinking outside of only what the manual states........ So does anyone have a better thought about the 'limp mode' issue. I reside in the DFW area and someone has mentioned in a post about a good TDI mechanic in this area, does any one know? Currently I am chained, but will drive slow and have that DFW mech do the fixin'......

[s4phillips]

Originally Posted by tlbo

snip... So does anyone have a better thought about the 'limp mode' issue. I reside in the DFW area and someone has mentioned in a post about a good TDI mechanic in this area, does any one know? Currently I am chained, but will drive slow and have that DFW mech do the fixin'......

Look in this thread for DFW area shops that work on VW TDIs and have experience with BSM replacement/upgrade: http://forums.tdiclub.com/showthread.php?t=293773
You might also contact a member here that goes by jetta ,97 for diagnostic help. You can find many of his posts and reviews of his work in the Meetings/GTG/Regional Discussions ->South Central Regional States section. I have no personal experience with any shop as I have done everything myself except for one re-flash for one of the glow plug changes.

I have to think these limp mode events are caused by leaking vacuum hose or connections, a charge hose leak on the intake track, bad N75 valve, sticking vanes on the turbo, or perhaps the tandem pumps is not creating the proper vacuum when cold.

[aja8888]

Ft Worth/DFW Guru's:

Jetta ,97
mtbr297
Alphasenior

All very good.