batchik2

My 86 z28 is smoking out of the cranck case ventalation hose into the air filter. can anyone tell me some possible problems with my engine

crucial

Bad rings... a lot of "blowby".

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1991 Z28

91'firebrd

Intake valves might not be seating.

GTA88

Sounds like blowby from rings, valves. I have the same thing on my 85 Caprice . I just took the crankcase ventilation hose off the air cleaner, so it wouldn't clog up my air filter. So now the blowby smoke just goes out that hose into the air.

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88 GTA 5.7 TPI Charcoal Grey Bone Stock except for loose muffler which makes it a bit louder than normal.

breathment

ok, i have a simular question and i don't really want to open a new topic since its Non F-body. my friend has a 70 Torino 351-C which used to run on leaded fuel. and they converted the carb to unleaded, but didn't change the heads out. and he is having the same problem with alot of smoke etc coming from the breather filter. could this be because the valve seats are bad since there was no lead in the fuel to condition them and keep them from getting bad?

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- David
88' GTA 5.7L TPI MODS---> air foil, K&N, Shift Kit, 180* therm, TB bypass, Gutted CAT, Flowmaster 80 Series

JakeJr

The best way to tell if it's valves is with a leakdown tester. Since most guys don't have one, and the air compressor needed to operate the tester, the old method of compression testing can be used.

It's not as reliable, but if one cylinder pumps a LOT lower that the others, then you've found your culprit.

Then squirt a bit of oil - about a tea spoonfull - into that spark plug hole. If compression increases a lot, it's the rings. If compression only increases a little or none at all, it's valves.

As mileage accumulates on an engine wear occurs. As ring seal deterioriates increasing amounts of compression leaks, enters the crankcase and is vented into the PCV system. Leaking valves allows combustion pressure to be forced back into the intake tract, diluting the mixture and hurting power

It's normal to see a slight amount of smoke coming from the cover with the PCV removed/engine running, but if it puffs like a coal burning freight train, has an intermittent puff or is excessive, you've definitely got a problem.

There are no gimmicks or workarounds that I know of; it'll be new engine/rebuild time.


Hope this helps.

Jake


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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9, TPIS Long Tube Headers and DynoMax Super Turbos (HATE 'em)

Sitting Bull

Hmm, replacing the little $2 valve on the driver's side valve cover fixed that problem for me. Once I did that, the blow-by almost disappeared.

JoelOl75

If it's blowby, it's not going to dissapear by chinging the PCV valve.