350 chev problem

**thatotherguy** · 10-03-2012, 04:15 PM

hi all i have a 350 chev was a crate motor and has done very few ks but has been sitting for 14 years and only taken around the block occasionally, it has great compression and even on all cylinders and runs really well but the problem is it blows blue smoke out of the exhaust and only after it warms up ,no smoke at all when its cold. so before i pull it down and rebuild it has anyone got any ideas as to what it could be besides oil rings thanks

**green taxi** · 10-03-2012, 04:37 PM

could be valve stem seals

**HK1837** · 10-03-2012, 10:15 PM

Agree. Gone hard.

**adam perth** · 10-03-2012, 11:43 PM

you don't have to take engine apart to change valve stem seals.. put compression fitting in the spark plug hole and take collet off valve.

vale stem seal kit is about $1.50

**wbute** · 11-03-2012, 07:51 AM

I could be wrong but don't valve stem seals let oil into the bores when the engine is not running, then blue smoke on start up which goes away when the engine warms up? No doubt it is the valve stem seals, but I don't know if it has a PCV valve, but it could be blocked up making it suck oil out of the sump as well. Is it blowing the dip stick out as well?

**thatotherguy** · 11-03-2012, 01:12 PM

no it doesnt blow the dipstick out and i took the pcv valve out to make sure it wasnt that and it has a single system on it so i dont even know if it is just one bank and i thought if it was valve stem seals it woud smoke when cold not hot . i am just looking for ideas before i waste money rebuilding it thanks for all your help at least i wont be bored this winter

**mrsandman** · 11-03-2012, 02:59 PM

i run an engine shop(warbuilt) it sounds to me like valve stem seals. at idle the engine has vacuum and will suck oil past seals if they have gone hard. as the engine heats up the oil thins out making it easier to suck past. as others have mentioned , it is easy and by far the cheapest fix to try. failing that it could be intake manifold gasket.

**HK1837** · 11-03-2012, 03:02 PM

Could also be the modulator on the auto transmission if it has one. When these go the engine sucks up tranny fluid via the vacuum pipe.

**thatotherguy** · 11-03-2012, 03:58 PM

thanks guys i need to take the inlet manifold off as it looks to be leaking so i will go from there and it has a T700 in it so no modulator thanks again