Audi A3 TDI Power Loss

Noticed this a couple of times now, whilst I’ve been driving it’s felt like the car has temporarily hit limp mode whilst I’ve been driving. My Audi A3 has been developing a power loss.

I’m not worried about engine timing, VCDS shows the torsion value around 0.5′ advanced, and the timing belt was only changed about 1000 miles ago. So the problems aren’t related to engine timing

What I suspect the problems are, is either due to clogged injectors, or possibly a clogged up fuel filter. I’ve done a quick scan of the car and there’s only Electrical faults in the loom. Nothing related to Engine Misfire, either that or it hasn’t logged a hard fault with the engine yet

I’m going to run some diagnostics with VCDS and follow it up.

It tends to happen around 3300rpm when I get to around 3rd or 4th gear. It’s not limp mode, just feels like it’s temporarily struggling and then goes again. It doesn’t stop the car, it continues pulling hard. Just feels like it’s a sudden loss in fuel delivery

I suspect the car hasn’t had it’s fuel filter replaced, but I’m going to run through some injector cleaner in the tank to see if it cleans it up. If not I’ll replace the filter as a precaution. The VCDS tests will help pinpoint any issues with the injectors on the car


More to come…



So, did a power run. Didn’t see to have any issues on the 1st run, but the second run was obvious. The engine felt really laboured to pull hard and became iffy a few times. The first run the engine was cold, the 2nd run the engine was operating temp

The VCDS logs don’t show any obvious problems with the Mass Air Flow Sensor or the Fuel Injectors during the runs. At least going by injection quantity. I’ll be looking at the figures further to see if there’s an Electrical problem with an injector somewhere. Although that would cause a misfire I would imagine.

I’m also thinking along the lines of a possible boost leak in system somewhere, potentially opening up when warm

I’ve uploaded the two data loggings I did to a website (TuneZilla Log Viewer), the only thing I can see is that when I run out of power the engine appears to want negative timing. Not sure what this means yet, but it appears to coincide with every time I lose the power. So possibly is hitting a temporary limp mode.

Fuel cleaner didn’t seem to do much. I’ll check the filter as a precaution as these cars can have Tandem Pump issues too.



To be added when identified

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