Audi A3 8P - 2.0 TDI 103kw cr - Loud ticking/tapping with cold engine. Only happens under load

[sayn117]

Hi everyone,

My 2010 A3 2.0 TDI (cr enigine) is the first Audi (and diesel car) that I've owned. The engine seems to making a quite loud ticking/tapping noise when the engine is cold.

This only appears to occur when accelerating and the engine is under load (there's no noise when just revving whilst in neutral) and the ticking kicks in when at 2k revs.

Once the engine is warm the noise is pretty much gone.

I don't suppose anyone has any idea what the cause could be?

Thanks in advance.

 

[sayn117]

Any ideas anyone? Its the fact that the noise only occurs whilst the car is under load and accelerating that makes it hard to diagnose.

 

[ch1z64]

Read up on this post . ( https://www.audi-sport.net/xf/threads/a3-2-0tdi-ticking-noise.278499/ )

 

[sayn117]

So I found a YouTube video of someone with an CFFB engine (in a different car) with what appeared to be the exact same issue as me. Theirs was diagnosed with injector problems so I hooked up VCDS and checked the injector deviation.

On an engine that had been run for a couple of minutes (so still cold) I had the following:
Cylinder 1: 0.23
Cylinder 2: 0.18
Cylinder 3: -1.66
Cylinder 4: 1.12

When driving and maintaining around the 2k rev mark Cylinder 2 went really out of balance.
Cylinder 1: -0.98
Cylinder 2: 3.00
Cylinder 3: -1.01
Cylinder 4: -1.02

I'll do a hot engine this afternoon. When is it best to check injector balance (hot or cold engine)? Should Cylinder 2 being at 3.00mg/stroke whilst under load set off massive alarm bells?

Thanks again.

 

[KieranLH]

Having the same issue with mine, only had the car 2 weeks

 

[ScottyP45]

This was a common fault on pug and Citroen HDi engines when they first appeared, and was due to the pilot injection not happening to quieten down the combustion clatter. Could be as simple as swapping the injector and recoding with vcds (which needs to be done so the ECU knows the injector parameters) if it's faulty, or just recoding the same injector only, so the IMA is reset to zero. Don't touch the others.

If you can get a pilot injection relearn done, that might fix it unless the injector is really physically faulty. If anyone has just bought a car, the previous owner could have fitted an injector and not coded it, with similar results.

See here under "Special Functions"

 

[Ath]

Did you get this sorted as got sort of the same sound on mine now with tapping clunky noises when under load in the 1500-3000rpm range any suggestions much appreciated

 

[sayn117]

Faulty injector. Hook up your car to VCDS and check the injector deviation of you can. Once the injector in cylinder two on my car was changed the tapping was fixed.