my engine burns oil like crazy. like a quart every 300-400 miles. I read that a vacuum leak will cause excessive oil burning, but this much? i dont have a gauge, but it cant be off too much. What are common reasons for this. I only have about 3500 miles on my engine. It doesnt smoke like its burning in the combustion chamber.

 

If you have no external leakage, it must be burning. Have you taken a close look at the PCV valve and crankcase vent?

 

thank you for the response. by checking the PCV valve and crankcase vent, i am confused. PCV- check if it has a good seal or if it is broken or hooked up wrong. crankcase vent, i am unsure what you are talking about, i am guessing the breather on my valve cover? thats the only other vent that i know of. should i see if it is not breathing, as if it is plugged up? Also, i am not sure if it matters but my brake booster is hooked up on the carb to where the directions say to hook up the PCV valve and the other way around for the other line. i was under the impression that they all have the same vacuum so it doesnt matter, but i am open to suggestions. it is kind of scary when ive got my life savings under the hood. thank you, --travis

 

83,

Look inside the PCV hose and at the valve. If oil is being sucked through, it should be apparent.

You should also see if oil is being pumped out the breather, but that would create an external leak in your case.

 

A cat will often hide a fair amount of oil smoke.

Oil doesn't just disappear. It goes somewhere. It's either leaking, or it's going out the tailpipe, no other possibilities.

The kind of vacuum leak that causes oil consumption is where the section of the intake gasket that goes across the bottom of the intake port, has failed. That's a direct connection between vacuum and oil. It's more common than people might think; I've seen more than one motor junked for that, because somebody thought the rings were bad.