ok so on my 1988, inline 6, i had blowby coming from the front hose into my air filter i replaced the valve cover with one out of a 96 and i replaced the oil pump and the oil sender. now its leaking oil from the oil cap. besides a broken ring what can cause this.

 

Try Lucas oil additive or similar product, eliminates minor blowby

 

Valves sticking and worn piston rings are about the only causes of blow-by. At my shop, if it has blow-by, it gets rebuilt or replaced.

Easiest way to figure out if you need a rebuild is to do a compression test.

 

ok so my back vacum hose was clogged i replaced it and the problem was solved