Has anybody any experience with these 2.5 v6 bdg engine code. Had it on vag com today to check fuel pump timing as car is idling low at 719rpm plus gives a puff of smoke when starting cold. So far have changed all glow plugs, timing kit and water pump, full service plus egr and inlet manifols has been cleaned out. Theres no fault codes stored. Any ideas what could be causing the low idle and smoke

Smoke might be due to retarded timing, on an old 2.5V6 BDG you really want it around 0.2ATDC+-0.2deg for clean starts, even new ones needed less than 0.8ATDC.

 

Has the low idle been there before timing belt change? If yes, it might just need adjusting, login 35342, and I think 2nd adaptation  (idle speed) with VCDS.

 

I would check basic timing with VCDS (measuring blocks - start of injection then switch to basic settings ad look at the "late" timing values, should be 0.2deg ATDC, after adjustments "early" should get to 15deg BTDC), then adjust idle.

 

But if low idle and smoke appeared only after belt change,likely the belt jumped by 1 tooth and the engine needs to be retimed.