Any help much appreciated!

[Nth95]

Hello just joined and looking for some help or advice if possible, thank you!

Audi a3 2005 2.0tdi (bkd 140) 119k turbo reconditioned & dmf + clutch replaced in November car is completely standard.

Car ran absolutely perfect with no smoke or loss of power at all up until recently..

First I noticed some light black smoke when revving the engine then the following week..

Started getting rough idle when reached temp (90) with black smoke and a awful rattling noise with a brief loss of power if I put my foot down I'd have to limp it some yards and it'd 'sort itself out' the rattle would go away and power would come back til I tried putting my foot down again. The rough idle is always there when temp is at 90

Eml light comes on the dash when this happens but vagcom shows no codes

Thank you

 

[34stuey]

Hi and welcome to the forum.
I’ve not come across the issue you describe so I’ll share my thoughts.
First a few questions - when starting from cold what are the symptoms, the same as described or none? Are the symptoms you describe the same when starting with a hot engine?
Based on your description it may be due to a faulty temperature sensor so ECU thinks engine is still cold and is delivering a rich mix hence black smoke. ‘Rattle’ could be result of poor combustion due to rich mixture. From my previous VAG vehicle experience a faulty temperature sensor may not show up on VCDS. I think there maybe two temperature sensors on the TDI but I might be wrong on this. Hope this helps.

 

[Garrett 69]

Funny that there's no codes logged, I'd expect a faulty sensor to record one.

Worst case scenario I'd suspect either injectors or HPFP.

 

[Nth95]

Thanks for thr replies!

Cold start runs absolutely lovely starts straight away with a little vague puff of blue smoke. When warm again it'll start straight away and run lovely but except soon as the temp reaches 90 it'll idle lumpy, hot or cold if you try out you're foot down it backs off and starts rattling.

Ok so today eml flashed. Plugged it in straight away and it gave number 2 injector + abnormal readings on the MAF?