How to check for valve guide wear.

[axl911]

I am getting ready for a valve adjust on my C2. While I have the valve cover out, I'd like to check my valve guide for wear.

I understand that I can use a screwdriver to wiggle the valve? Where/how would I do that?

Use a screw driver to try and wiggle where the arrow is on the picture below right?

And I must do this when the valve is closed right?



thanks,
anthony

[axl911]

Anyone?

[Eagledriver]

I've never done this but my understanding is that the valve must be open to do the check. If the valve is closed the stem wont rock back and forth because the head of the valve is keeping it from moving. If you want to try it I would have the valve open about .1 inches and push on the valve stem to see if it will move sideways. Don't know how much they should move. I usually just assume they are ok until oil consumption gets too high or I see carbon building up on the valve stems and springs.

-Andy

[RoninLB]

JW has posted that the wiggle measurment isn't the best..
but the book says a wear limit of
.15 for intake
.20 for ex
for '65-'89

[Rondinone]

Smoke after decceleration is a good indicator. Next time you get off the highway, coast to the end of the exit ramp under high engine rpm to generate a strong vacuum in the intake manifold. If your guides are worn, you'll suck oil into the intake down past the valve guides and there will be lots of smoke.

[Rot 911]

Originally posted by Rondinone
Smoke after decceleration is a good indicator. Next time you get off the highway, coast to the end of the exit ramp under high engine rpm to generate a strong vacuum in the intake manifold. If your guides are worn, you'll suck oil into the intake down past the valve guides and there will be lots of smoke.

Actually you will only see oil smoke if the intake valve guides are worn. If the exhaust guides are worn, like mine were, you won't see any smoke because the oil gets sucked into the exhaust unburned.

[88911coupe]

Frankly, I'd have a hell of a time guessing how much a screwdriver is moving a valve stem back and forth. I think you have to know what you are doing to really use this. Although I suppose if its really moving you probably have worn valve guides. If you are using a lot of oil and blow smoke on decel just assume you need valve guides.

[RoninLB]

If you can detect movement the guides are worn. Valve guide seals are another consideration for oil burning.

[axl911]

From reading the old posts, I'm a bit confused. Are the movements up and down or sideway?

----
anthony

[dmac]

Side-to-side!

[Rondinone]

Originally posted by Kurt V
Actually you will only see oil smoke if the intake valve guides are worn. If the exhaust guides are worn, like mine were, you won't see any smoke because the oil gets sucked into the exhaust unburned.

Why would the exhaust guides be worn but not the intakes? Did you have an oil circulation problem?