Uses oil valve guides?

[Asahi123]

Done a compression check on all cylinders average 170. No oil leaks could it be valve guides or valve seals? I checked it when I start doen't see any kind of smoke out of the tail pipe. If the compression is good could it be the rings? Pulled all the spark plugs and they all look normal. Any suggestion.

[68gmsee]

How much oil does it use? One quart in 1000 miles is not bad.

Re. the oil usage. Yes, it could be valve guides or seals or oil rings. The compression itself is not an indicator that the rings are all good. There could be enough oil on the cylinder walls to give good compression. I'd start by replacing the seals since that's the easier and cheaper thing to do.

[pritch]

I had always heard this, and then I had a car that it was true on, so maybe try this simple test:

At night, find a long hill on the Interstate that you can coast down at a decent speed. Let off your throttle as you are going down the hill, with you car in gear, and when you've gone a mile or so, floor it. If it's valve seals, you'll lay a smokescreen down that you wouldn't believe. That's one of the reasons to do it at night. The other is that it's easier to see the smokescreen through the head lights of the cars behind you.

[GRX]

Originally Posted by 68gmsee

Re. the oil usage. Yes, it could be valve guides or seals or oil rings. The compression itself is not an indicator that the rings are all good. There could be enough oil on the cylinder walls to give good compression.

^^ This. What engine are we talking about? Check your PCV system. Remove the oil fill cap. If you see smoke good chance it's the rings - blow by. Also, excessive smoke when letting off the accelerator while in gear going down hill is another indicator of bad rings since you are increasing vacuum within the cylinders - sucking oil.

[Asahi123]

350 engine checked PVC valve is and good. I have to try the down hill.
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[chopnchaneled]

If its valve stem seals, after driving for a while and you cut it off and the next morning when you crank it and there is a cloud of white/blue smoke, it's valve stem seals.

[ChevLoRay]

Bad valve guides will allow oil to leak past the valve stems and collect in the cylinder on top of the pistons. If it smokes when you first start it up, it's a sign that the guides are allowing the oil to leak past them. People who have done an old-school re-ring and bypassed doing the heads, find the increased compression/vacuum pulled oil past the stem, too. BTW, same type of folks have done a valve job w/o a re-ring/rebuild on the block and found the increased vacuum caused an increase in oil consumption as it was easier to get the oil past the rings and into the combustion chamber.

Blowby will produce oily vapor from the valve cover when you pull the PCV valve or the fill cap. You can see it when you rev the engine, with the hood open and you watching. You'll probably see the stuff accumulate on the engine.


Studebaker used an umbrella-type seal for the valves that is an old trick to keep the oil from running down the stems. It's old-school, but it works and was a very common way to temporarily stop the leakage.