1968 Barracuda 318 Smoking....good compression

jamesromeos said

The plugs were black and wet looking, i changed the oil to no avail. Can you tell with the valve guide seals if they are gone bu look if i pop a valve cover off?

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Yes, where the material has failed significantly. Look through the valve spring to see the nipple where the valve stem comes through the cylinder head. If you see a complete rubber dome around the valve stem, the seals are probably OK. If a chunk is missing there's a potential problem.

I agree that getting the engine up to operating temperature for a hour or so is a good way to get rid of condensation in the exhaust system, crankcase, and valve covers. Another way to check is to have another person follow at a distance. Get the car up to ~ 45 mph in high gear, drop down to second and let go of the gas pedal. This produces maximum vacuum in the engine. With the throttle plate shut, the engine is going to suck air down any available path. If the valve seals are gone, this procedure will produce smoke that can be seen from the following car.