Exhaust query

[wrenko]

Off and on noticed occasional smell exhaust fumes in cabin. Only happens briefly at start up and then goes. Different dealers had couple of goes but found nothing. However, cold weather proved useful because when cold noticed that sometimes when starting up in morning nothing comes out of exhaust and instead seems to be come out from under centre of the car. After couple of minutes it's like a switch is flicked because exhaust kicks in nicely with expected white vapour.

Will try exhaust specialist next but is there any logic here when starting from cold??

[jimbof]

I heard from somewhere that if the plenum bungs have been removed to stop the water accumulating, while stood still you may get some exhaust odour into the cabin.

[jimbof]

I heard from somewhere that if the plenum bungs have been removed to stop the water accumulating, while stood still you may get some exhaust odour into the cabin.

It was here:

http://www.vwaudiforum.co.uk/forum/archive/index.php/t-120965.html

Quite the heated little debate. And of course it is all true; if the plenum is kept clean the bungs wouldn't be a problem. But reality says it isn't kept clean and so they are a problem!

[CRC]

My V6 does exactly the same, and has done for the last 4 years.

There are two schools of thought on this one. When I first tried to hunt it down, it seemed as if exhaust fumes were coming up into the engine bay from somewhere in the vicinity of the turbo. One there, they get sucked into the fans on the climate control unit and then you smell them.

The other possibility is that if (like me) you start the engine up and reverse out, (rather than going forward), then, as the exhaust exits downwards onto the tarmac, the cold exhaust sits under the car and then gets picked up by the intake fans as you reverse back over this cloud of low level exhaust gases.

I've just learned to turn off the climate control before I start the engine on a cold day, and while I can still get the odd fume into the car, once I've travelled 20 yards, all is fine and I just turn the climate control back on again.

Bit of a bind, but no real problem.

[wrenko]

Thanks folks. Appreciated. Will check out Plenum and adopt CRC's technique as yep I reverse out. Last year with her anyway replacement time is here.

[oh_superb]

I have exactly the same issue, doesn't bother me at all... many TDis have this... love Vee Dubs....