I have a 79 with a SB400 and I am getting some oil smoke. I figured that it was the valve guide seals, so I had those changed out. That fixed the problem, and two days later I got on it pretty hard in 1st and she started to smoke again. What do you think could be wrong, maybe valve guides, rings, or look elsewhere??? Also, when it is just sittin, it blows a little smoke, and when you romp on it, it blows a HUGE cloud. I don't know??? /forums/images/graemlins/1zhelp.gif /forums/images/graemlins/thinking.gif
CK5
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Oil Cloud???
- Thread starter earlthek5
- Start date
TrcksR4ME
1/2 ton status
Probably rings, how many miles on it? Sounds typical of an engine thats about used up, have you lost some power as well?
It could be the rings--or a piston--my six cylinder died rather suddenly with no real warning,started huffing oil out of the breather,pushed the PVC valve right out of the valve cover,and smoked like a chimney out the tailpipe--all I could find wrong upon teardown was a small chunk of the #6 piston was missing at its outer edge--you could see the top ring!.I assume spark knock had beaten the piston so much it finally cracked a peice of it off. /forums/images/graemlins/confused.gif
I'd check and make sure the PCV valve has good vacuum,and its hoe isnt collapsed,kinked,or blocked at the nipple where it goes to the carb or intake before blaming the rings--a compression test may help pinpoint a problem in the rings,but I've had a few chevy motors that showed excellent compression,but still smoked pretty bad--I concluded the oil control rings were worn,but the compression rings werent.Or maybe the pistons were too sloppy a fit in the cylinders,making the rings work overtime keeping the oil down in the crankcase.
I have seen more than a few engines start using oil or smoking after the owner put a set of aftermarket vale covers on that didnt have a breather hole,causing the PVC valve to suck air past the rings,bringing oil with it,and it burns in the combustion chamber--makes lots of smoke.Bad intake guides will let enough oil down onto the piston to make a good cloud when you first start it up,then it will subside after a minite or two--even new valve stem seals wont cure loose guides,but this is usually more of an annoyance than a serious problem--the 86 305 I put in my 79 C10 does it every time I start it--I'm not too concerned--the "chevy puff" is common among many small blocks. /forums/images/graemlins/crazy.gif
I'd check and make sure the PCV valve has good vacuum,and its hoe isnt collapsed,kinked,or blocked at the nipple where it goes to the carb or intake before blaming the rings--a compression test may help pinpoint a problem in the rings,but I've had a few chevy motors that showed excellent compression,but still smoked pretty bad--I concluded the oil control rings were worn,but the compression rings werent.Or maybe the pistons were too sloppy a fit in the cylinders,making the rings work overtime keeping the oil down in the crankcase.
I have seen more than a few engines start using oil or smoking after the owner put a set of aftermarket vale covers on that didnt have a breather hole,causing the PVC valve to suck air past the rings,bringing oil with it,and it burns in the combustion chamber--makes lots of smoke.Bad intake guides will let enough oil down onto the piston to make a good cloud when you first start it up,then it will subside after a minite or two--even new valve stem seals wont cure loose guides,but this is usually more of an annoyance than a serious problem--the 86 305 I put in my 79 C10 does it every time I start it--I'm not too concerned--the "chevy puff" is common among many small blocks. /forums/images/graemlins/crazy.gif
Mreetz
1/2 ton status
my 305 has the puff!
mr_beer
1/2 ton status
Sounds like rebuild time /forums/images/graemlins/doah.gif
