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smoke under compression

Posted: Tue Jul 01, 2008 4:26 pm
by Taff
Just picked up a new sierra. Engine idles great, revs great, has heaps of power (for a mighty 1.3) and starts fine but under compression braking it seems to puff alot of smoke. Any rough ideas on the smokiness? im assuming the worst and thinking rings are worn? havnt had it long enough yet to tell if its using much oil. It also coughs and splutters a fair bit under compression too, is this due to way too much fuel getting in or something to do with the exhaust? There is a light greyish buildup on the plugs.

Posted: Tue Jul 01, 2008 5:44 pm
by Mike_1324
If its sucking oil on roll on, its the valve stem seals, its a n easy fix.

They are probably rock hard.

MF

Posted: Tue Jul 01, 2008 5:54 pm
by joeblow
or the bores could be very glazed.

Posted: Tue Jul 01, 2008 6:11 pm
by want33s
I'd say valve stem seals too if it only smokes with NO throttle on.

Posted: Tue Jul 01, 2008 6:37 pm
by Taff
ill do a compression test on the weekend and see how i go.

Posted: Tue Jul 01, 2008 9:31 pm
by 83jack
i would say it is valve stem seals as well, if it was smoking on acceleration then it would be rings. a compression test wont really tell you if its the valve seals.