White smoke, but a black engine bay
Q My Lister SR2 starts fine and runs happily, but produces continuous white smoke. Also, the engine bilge is very oily and fuller than seems good, plus there is a fair bit of sooty deposit around the engine bay. Any thoughts?
PETE SEDDON, via email
A TONY REPLIES… As far as the oily bilge is concerned, it’s common with old engines, cleaning it is a horrible mucky job and far too often such things are ignored. It might or might not signify an oil leak, but the only way to find out is to clean it and see if it starts to fill with water or oil.
At least the SR is air-cooled so it won’t be a coolant leak, but it might have resulted from a leaking stern gland or loose weed hatch.
Sooty deposits could be from an exhaust that is broken under the lagging; rubber dust from a wearing alternator belt; a blowing exhaust manifold; or maybe a slight blow on a head gasket. If it starts easily and runs happily, I would not worry about a slight head gasket blow, as there is no oil or coolant near the gasket.
White smoke could indicate injectors needing overhauling, faulty injector pump timing, or incorrectly set pump clearances, but the latter would probably give rise to poor starting.
Lister engines have a lot of internal fuel pipes and when these develop leaks the sump starts to fill up, resulting in high oil level, thin oil that smells of diesel, low oil pressure, exhaust smoke, potential seizure or runaway. This could be the cause of your smoke.