sudden...immediate....consistent loss of acceleration

2003 Jetta TDI Turbodiesel.
I was passing someone this morning at 110km/h, when all of a sudden there was a loss of acceleration. I was in fourth, shifted to 5th, and then there was ....nothing.
I'm talking 5 tonne tandem axle truck slow.
No warning lights, no overheating, just a loss of acceleration. I don't mean that the car has become slow..... I mean it has become dangerous-to-pull-out-in-front-of-oncoming-traffic slow.
What's my first places to check? Blown turbo? Suddenly clogged fuel filter? New to these motors, so I don't know all their quirks yet.
Thanks.

Unplug the maf and see if some performance returns.

BeeselDietle said:

Unplug the maf and see if some performance returns.

Click to expand...

Good first test!

After that, go over the "Limp Mode" troubleshooting thread:
http://forums.tdiclub.com/showthread.php?t=179589

All the best,

Yuri

Okay, I'll check that out, but it seems to be better already. I stopped off at one school, typed out the first message, then left for my next school I teach at.

Got in the car and it seemed that immediately the performance returned.

I second the limp mode suggestion.
If the car goes into limp mode bacause of boost issues it will reset when the engine is turned off. You could turn the engine off and then back onn again while moving to reset it.

Definitely sounds like 'limp mode'. I had this problem several times but not all of the time. It always went away after the ignition was cycled and it never kicked on the MIF. After about a month of this happening maybe a total of 10 times it did light the MIF. The source of the problem was a low boost condition caused by a leak at the EGR cooler. These are known to fail and some were recalled. The situation with mine was that someone replaced the bolt with an incorrect one and stripped it out.

As for the power loss you describe...I could not get my 04 Jetta over 55mph on flat ground when this cropped up. Best of luck with this!

dunl said:

What's my first places to check? Blown turbo? Suddenly clogged fuel filter? New to these motors, so I don't know all their quirks yet.
Thanks.

Click to expand...

Just do a search on "limp mode". If it happens again, just push in the clutch or shift to neutral and do a quick restart.

If it starts to happen frequently, then you'll need to start troubleshooting.

One thing you might do: if you're climbing a hill and trying to pass someone at the same time, downshift. Limp mode is more likely to occur if your engine is at low rpms in a high gear, and you try to accelerate briskly, and especially uphill.