2005 TDI Passat excessive drive train vibration

redmax

Active member
Joined
May 8, 2005
Location
NE, USA
TDI
2005
OK, I purchased a new automatic passat TDI 2.0 L in May 05. About two months ago, the car fuel filter plugged at 25K. The book said to change at 20K and I drained the water separator by mistake.

Anyway, the car was towed to the dealer and left in the shop. At first I thought the fuel gelled and it would be a matter of thawing out. But the dealer found the problem and replace the fuel filter.

While driving home, I immediately notice high vibration during idle modes for example at stop lights. The vibration was worse if idling on a hill.

I finally had the car serviced and they replaced the motor mounts. I asked the technician and he has not seen motor mounts changed at 30K. No VW tech specs either.

The vibration has been reduced but it still vibrates more than it originally did.

Can anyone tell me other things that I should checked? I am considering buying some fuel injector cleaner and try. When the car in moving, it is smooth. Again only in idle and especially when in gear.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Does it do it all the time, or after the car sits and idles for a minute or so? The EGR valve is open at idle, but after a minute or so it shuts, and the engine sound/vibration does change noticably (although more pronounced outside the car).

You may also have a prematurely gunked up intake or EGR/throttle valve assembly. If your fuel filter got gunked up at 25k I'd suspect you are getting some pretty bad fuel. I've never ever had a diesel fuel issue in any of my cars, but I change the filter every 20k religiously on everything.

The EGR is relatively easy to remove and check.
 

Dimitri16V

Top Post Dawg
Joined
Jan 30, 2005
Location
DE
TDI
01 Golf, 04 Golf
there is a service bulletin for this. Flashing of the ECU and adding some grounds on the ECU harness. I would have them check the tandem pump too, for leakage. my 04 golf vibrated like that at idle. Did the above and it is all good now.
 

redmax

Active member
Joined
May 8, 2005
Location
NE, USA
TDI
2005
To answer you questions, the vibration really picked up after the fuel filter was plugged. And it occurs at idle while the car is in gear. If I am on a grade, the vibration is worse verses a level street setting. I travel via highway and the mileage is reasonable between 38-40mpg depending on the amount of equipment I need to carry.

The replacement of the motor mounts made a substantial difference. I had the car towed and wonder if the hitching and loading process had something to do with it.

It is under warranty and the technician check the for any codes. I just hung up the phone and will stop in with your recommendations;
- checking the EGR Valve
- flashing the ECU
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Ah, the TOW COMPANY! That's the key! They clamped down on the subframe when they hooked the car up I'll bet and tweaked something.

If it is put up on an alignment rack, I bet the whole story will come out. The lower control arms are attached to the subframe, as are the engine mounts....I'll bet you'll find they mangled something.

Makes sense since you said it started right after the fuel filter gunked up!

That sucks!:mad:
 

redmax

Active member
Joined
May 8, 2005
Location
NE, USA
TDI
2005
I still have the high vibration. The dealer is pulling in a VW master mechanic in a few weeks. I will post the results.
 
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