Date: 8 May 1998 00:13:24 GMT From: "Simon " <swellernopsamral.co.uk> Subject: Re: Cure for smoking 900i (1985) ???
Robert, When an engine smokes under power it tends to be rings, either compression but more probably oil control (as Colin stated) But smoking on the overrun points towards valves. As your car is stored this would lead me to think that the valve seals have 'dried' out and are no longer sealing properly. . . But they've been changed. . .Correctly?? Still on valves, the stems/guides could be worn. Especially if it is a short trip car and stored. Black sludge forms, as does condensation (white mayonnaise) neither of which are renown for their lubrication properties. Hence accelerated wear of the valves/stems. Simon Brighton UK > > > Robert Clark wrote: > > > I have a Saab 900 1985 (8-valve injection). The car spends long periods out > > of use (sometimes several months) in a basement garage. > > Recently, on starting after standing for about five months, it started > > smoking badly from the exhaust - a cloud of bluish-white smoke when going > > back on to the throttle after being on the overrun (eg after a downhill > > stretch). The car has done 120,000 miles. Obviously it is burning oil. > > A Saab-trained mechanic changed the piston rings and honed the bores. He > > also fitted special seals to the valve stems. When the engine was put back > > in the car it still smoked. > > The mechanic then had the head pressure-tested. The test confirmed that it > > is not cracked. But it still smokes. > > Can anyone suggest a possible cause? > > > > Thanks > > Robert Clark > > England > > > >