My 1987 subaru gl  is burning oil bad.Using 1 quart every 50  miles.Could it be a bad pcv valve doing it.Where is it located on this car.Need some advise.Thanks

Jerseyville huh? that's near where I got my loyale over the winter. Anyway, mines fuel injected so it may be different but it was located on firewall side of the intake manifold, center lower portion. Follow your hoses out the valve covers and see where they go. Youd have oil all over the inside of your engine compartment. Whats your tailpipe look like?

+1 on colemanapp suggestion, with that much oil loss it should be pretty easy to locate where it's leaking

 i started this post. I finally used mopar combustion chamber cleaner and it cured my extreme oil burning and use. Thanks

PCV is located on the back of the intake manifld just to the left of the throttle/carb. 17mm tool will service it. The car is either sucking up oil thru the pcv, or if it is clogged, over pressurizing the crank forcing oil out. Inspect the hoses associated with it as ell for being sudged or clogged like coroded arteries.

 

What weight of oil are you using? Best to use 10-30, 10w40, 15w40, or 20w40 or 20w50. avoid 5w30 unless sub freezing temps. 10w30 all around, heavier weights depending on mileage and consumption

Obviously as used car has said combustion chamber cleaner fixed the issue so therefore what would have been happening is carbon buildup has caused the rings to stick most likely the compression rings which then pressurizers the sump so it pumps the oil past the rings and into the cylinder where it burns the oil and fouls plugs eventually.

 

And yes that will also clog up the Crankcase breather valves, PCV valves will; sometimes cause this issue but with a flat four never forget they are more prone to Oil sitting around the pistons and turning to Varnish and then sticking the rings with all the blow by and issues that come with that.

 

When it comes to blocked PCV valves and the symptoms of a Blown Motor one cannot go past the Rover V* in the Range Rover for that problem, Way too small a PCV circuit on them which clogs up real easy., Subaru's not so bad in that department.