Is there supposed to be some blowby air or no air coming out of the oil filler hole when the engine is running?

 

There should be an engine oil filler cap when the engine is running. A little tiny whiff of air wouldn't bother me much, but more than that would have me checking the crankcase ventilation system.



(must resist urge to check for blowby out the filler cap tomorrow morning before leaving for work . . .)

 

If there is air coming out the filler hole when the car is idling the PCV system is too weak, vacuum too low, PCV valve plugged or bad rings, to overcome the blowby pressure. More than likely if it's an older motor it's carbon behind the rings. You will probably see blue smoke from the exhaust at night in the headlights of a car behind you or smoke when you first start the motor after sitting a while too,



Auto-RX will fix this but it takes awhile. Worth the time and trouble if you are going to keep the car. Improves power, gas mileage and lessens oil consumption.

 

as long as it doesnt feel like the pressure an air compressor would make you may be able to save it, seen two cars with blow by the bad my buddy's honda and my 99 tib i had neither motor lasted long after the blow by got that bad but they both had rings worn and highly abused motors, it may not be anything to worry about tho just check the pcv valve and the vacuum line leading to it to make sure their not stopped up, i had a blazer that i spent hrs fixing the pcv system on cause the vacuum port on my throttle body had so much coked up oil in it i couldnt even fix it