Intermittent oil leak

My son has a 1994 Honda Civic base model. He has a mysterious oil leak. He says that he can go a couple of weeks without having to add any oil or a couple of days before he must add oil. Nothing appears to be leaking out, although he lives in an apartment so it is hard to say if any oil on the ground is his or another car. He says the car doesn’t smoke. There was no oil in the air filter compartment. He says that the amount of driving doesn’t seem to coincide with when and how much it will leak.

Any ideas?

I’ve never heard of an intermittent oil leak. Once something starts leaking it usually continues to leak. If there IS a leak, you should be able to see it somewhere on the engine.

The oil may be burning in the engine even though he can’t see any smoke. The catalytic converter does a really good job of burning up the oil so there’s no smoke.

How much oil is he adding when he adds it? How many miles on the Civic?

I Would Wonder If The PCV Valve Is Sticking Or Freezing (Climate Permitting) ?

If it’s got a PCV valve and it’s easy to get to and it’s cheap then why not put a new one in there ? Also check the PCV system’s tubing / hoses for being free from restrictions.


It depends…sometimes he adds only a quart, but yesterday he saw that it was down a lot and had to add 3qrts.
He has 253,000 miles.
Could there be a PCV valve or other valve that is stuck closed and thus once the pressure builds up enough it just blows the oil out at one time?
Although, he claims that he could leave his car for 3 days and not drive it and the oil could go down with no visible oil slicks or drive it for two weeks and no loss of oil. Realize he is not mechanically inclined, so I don’t know if he is missing something that would be obvious to you or me.

Hey, That’s What I Suggested, Already!