a4 tdi PD Engine...how true is this??

[vw754]

I was told by an independent audi/vw man that when engine oil cap is taken of a running pd diesel engine,smoke puffing out is normal,all pd engines do it!

He showed me a 53 plate doing the same,he said this is normal for a pd engine. On an older (non-pd) engine its a bad sign,but not on a pd.

Just wanted to know how true this was,maybe he's right 37 years in audi!

 

[Macduff]

I've never taken the cap off a running engine but whenever I've checked the oil on a hot engine there was always a *little* bit of smoke when I removed the cap so I think it's nothing to worry about .

 

[A3-frankie]

how come you were taking it off a running engine? just curiosity...

 

[Karcsi]

I believe you do it to check sump pressure - you are supposed to blip the throttle as well (a bit messy). I remeber by Dad saying something about it yonks ago. Now, I can't remember whether having oil forced out is good or bad...

 

[Caesium]

Evey engine will puff out smoke when the cap is removed if it is hot, the crank case is full of oil smoke and when you remove the cap is escapes. this is why there is an engine breather that leads into the intake manifold, it captures the fumes and combusts them in the cylinder.