Audi A4 tdi 1996 - Power Loss?

Honest John Back Room » Technical matters
View Threaded
Tue 12 Sep 2006 13:29
Audi A4 tdi 1996 - Power Loss? - hm
Hello all,

My wife Audi A4 1.9tdi (90BHP) seems to have an intermitten problem which I have now felt for myself. I have only experienced it in 4th and 5th.

Situation 1: driving in 5th gear, engine underload (motorway slip road) accelerating.....the car got to 70MPH @ approx 2500rpm, then just lost all it's power.......changed to 4th...no power, changed to 3rd..no power, allow the car to slow down, back off the accel pedal, then she drives fine.

The same thing happen in 4th, but this time the car was at 3000rpm?.........does this sound familar to anyone?...........the car is serviced regularly (by myself)......

The car is currently driving fine, and I can not get it to replicate the issue everytime??

Also, is there a way of re-setting the ECU without a VAG Com?

Any idea's?? futher more (pls note this has always been there) I can here a good whoosing noise from behind the steering/dash...I know t must be the turbo but I can not see any leaks etc....and the car appears to have the pull from the turbo..I mean it is only a 90BHP, but is goes plantly well enough.

Many thanks...........laters H
Reply | Report as offensive | Link
Tue 12 Sep 2006 23:11
Audi A4 tdi 1996 - Power Loss? - Nige 101
HJ mentions a hose that runs from the exhaust nr the turbo to the ECU in his car by car breakdown. Look under "Whats bad". In my experience unlikely to be an ECU fault.
Reply | Report as offensive | Link
Thu 14 Sep 2006 20:01
Audi A4 tdi 1996 - HJ question - hm
The only hose I can work out is the one coming from the diaphram ontop of the turbo...HJ can you explain which hose it is?
Reply | Report as offensive | Link
Thu 14 Sep 2006 21:22
Audi A4 tdi 1996 - HJ question - tewby
had a similar problem on a octavia tdi which might help........ and it turned out too be an intermittant fault on the air flow meter which was giving false readings to the ECU which in turn stopped the car from boosting...
maybe something different but symtoms were the same..
Reply | Report as offensive | Link
Fri 15 Sep 2006 17:28
Audi A4 tdi 1996 - HJ question - hm
I'm thinking may be something similar...I would assume that all these faults would be logged in the ECU...I'm off the states tomorrow, planning to hit an Auto store and bring back a VAG Com.......then I will check the error codes etc......

How did you determine it was the Air Flow Sensor....did the garage 'plug it in'
Reply | Report as offensive | Link
Fri 15 Sep 2006 20:38
Audi A4 tdi 1996 - HJ question - tewby
yes i run a bodyshop which also does mech work..
any reasonably equipt garage should be able to scan the ECU its not expensive
although it can sometimes be indefinate..
its a regular fault on this engine..
Reply | Report as offensive | Link

Our honest used car pricing is a little bit different to all the others. You can get to our values through make or model - you don’t have to follow a prescribed route. Plus, it’s live, which means we can react to changes in the market quicker than any printed price guide.

Honest Used Car Prices

From which small car to buy at which price point to the best UK-built cars, our Top 10s have the lot. Click now for your shortlist.

Unsure of what to buy? Our Top 10s are here to help you....