On Alfa number 15
AO Platinum Member
Join Date: Dec 2005
Location: United Kingdom
There are 3 possible causes I can think of.
One is that one of the oil seals inside the clutch housing have become damaged. This will most likely be the input shaft oil seal on the gearbox. This will often also cause a slipping clutch.
Another is a damaged drive shaft oil seal. When the driveshafts are removed it is easy to damage the sealing lip. This can result in oil leaking onto the exhaust pipe, and usually a puddle under the car.
The other could just be down to oily hands getting onto things like the exhaust and the residue just burning off
Either of these problems could cause smoke in the cabin if the heater is on.
I would take it back to whoever changed the clutch and ask them to look at it if you are worried.
You will never be cool driving a Vauxhall.