The engine in my car consumes about a quart of
oil every 500 miles or so. I have owned the car for a few years and just added
oil when necessary without paying much attention to how often or how much, until recently.
There is no smoking from the exhaust on cold start-up or on deceleration/acceleration, no
oil accumulating in the intake manifold or the base of the air cleaner. I do have a closed PCV system with an adjustable Wagner PCV valve that is tuned for the engine and the valve covers are well baffled. No external leaks exist.
I replaced the intake manifold gaskets about two years ago as a result of a coolant leak above cylinder No. 1 and used the FelPro S3 gaskets and thread sealer on the manifold bolts, so all is well there.
I did a compression test some time ago and all cylinders are within 2-3 PSI of each other. I recently did a cold leak down test; results are 4 cylinders at 7%, 2 cylinders at 6% and 2 cylinders at 4%.
I recently replaced the valve stem seals even though the engine didn't exhibit any symptoms of worn seals but, it is an easy enough job.
The spark plugs are clean with no oil or unusual deposits.
Oil pressure is 75 PSI cold, 62 PSI hot cruise and 32 at hot idle.
The engine is a Ford sportsman block based 302 stroked to 331with 18,000 miles on it. Oil consumption aside the engine is a very strong runner.