I have an 01 Jetta TDI 1.9. Have a loss of power now and then. Turn the power off and back on everything is good for a while. Engine check light comes on after this happens enough times. Have replaced the air mass flow sensor several times, problem keeps coming back. Many mechanics just want to keep trying things, way to expensive! One says around 160,000 miles the arm to wastegate can stick but you can only replace the whole turbo, way to expensive!! I found a website that sells an after market arm for $195.00 but still uncertain this is the problem solver. Anyone having the same problem with an answer please let me know. Thanks.

 

I had the same problem and it was the MAF, but apparently this does not seem to be yours since you have replaced it more than once. My suggestion is to go to "dieselgeek.com" it has some pretty sharp diesel gurus. They will show you how to check the turbo wastegate arm and free it. They may also give you some guidance on checking the vacuum lines to make sure that the arm is being energized.

 

Correction to my reply. The website to go to is "tdiclub.com" not "dieselgeek.com" Sorry about that.

 

Hey kvwgrindle,

Glad I checked in today - I had EXACTLY the same problem (even have the same car). After lots of diagnosis and guessing, it turns out it was a bad "boost sensor". Every now and then, I'd start up and have no boost (also, the check-engine light would go on). Turn it off and on again and I'd have boost. The sensor was going bad and re-starting the car essentially re-booted the computer.

The dealer replaced the boost sensor and rechecked all the connections. It's been fine ever since (hope I'm not jinxing myself - we thought I was going to have to replace the entire computer!!??!).

The check-engine light should give you a hint with the code, but it makes sense it's electronic (not mechanical) since it's going away with a re-boot. If your turbo works sometimes, my guess is it's fine.

To get it accurately diagnosed, I had to get it into the dealer WHILE the problem was happening. Maybe the same would be true for you.

Good Luck!

 

KVWGRINDLE....I'm having a similar problem... I know this is an old post but I'm hoping you fixed your problem! I'll be driving and the power goes out...turn key off and back on...power is back. It happens every few minutes or even seconds sometime and it's driving me NUTS. It happens mostly on the highway but will happen elsewhere if I floor it. Was 'jettadriver' right? Did you ever figure it out?
If jettadriver reads this...how much was the sensor? and where is it?
Thanx!! Please let me know