Benny4294

So my newly purchased wrx sti developed a miss fire,
After diagnosing the fault it turned out to be low compression on cylinder 3,
Carried out a cylinder leakage test and it showed the exhaust valves to be leaking,
Have today removed the engine and both heads,
Cylinder 3 exhaust valve seats black with combustion gasses,
Cylinder 1,2 and 4 starting to go black but still sealing,
Have reground all valves,
Replaced all stem seals,
And tomorrow will fit back together with all new gaskets,
Has any one else experienced this?

blackvenom

Good luck, hope this sorts your issues. Shame to have issues with a new purchase

ianbott

Be nice to know how you get on with it. Completely unrelated I have a ride on mower that is suffering from loss of power and it is down the valves being coked up! Abybody have any advise to stop this happening as I don't have time to regrind valves every couple of dozen hours!

Cheers Ian.