Yo guys
i was running a turbo bluetop in ae86 ... it went kaput ..was still running but heaps of smoke was coming out of oil breathers on head.
My question
i pulled the engine apart and was sure it would be a piston skirt broken ... but ... all pistons were fine bar one that had a little crack in it on the skirt ..but it wasnt the one giving the pressure test reading of 100psi all the others were 200psi ...what do you guys think was the problem ?
my second guess is rings ..but could something have run a muck in the head ? valve seats ? ...
how do you check to see if rings are worn ?
and what tests can i do on head myself to check whats wrong ?
also 200,000kms motor ..and bearings were still mint
Usually they do two compression tests a "wet" and a "dry" one. The difference is in the dry on you just crank the engine over, but with the wet one you add some oil into the cylinder to seal the rings, if it still leaks then the problem is (usually) in the head.
Maybe a valve stem? Or a cracked valve? Not too sure man, did it happen when you were driving it, like it went "BANG"?
oh ..at the time i added some oil to the cyl ..about 1cap full amd it made about 10psi difference ..thats it ..it didnt go bang .. it occasionally puffed a little white smoke out the breather ...then about 1 week after the first smoke ..heaps came out ... i drove it home ..and fearing it had met the same end as the motor in my old car i just pulled it straight out rather than much round with the head ... cyl pressures were 1:200 2:200 3:125 4:200 ..dry test and wet test number 3 went to 135psi ..it was gradual but very rapid ..i spend a long time with my old engine trying to diagnose it ..changed head gasket etc ..so this one i just pulled the whole thing out
Thu, 20 February 2003 08:22
