So truck was making a funny sound... I was about a quart low on oil. Put oil in and I'm good now. Sound is still there. Still trying to figure that one out. Anyways. I have oil residue in the PCV hose at the air cleaner side. Any idea what this could mean?

Thanks in advance.

 

Blow by is my first guess. You'd need to be more descriptive in stating your problem though.

 

There's an oily residue in the PCV hose. The noise just is exhaust leak. We are just concerned about the residue.

 

There is also oil residue on the ring that holds the air cleaner housing to the top of the throttle body. Is this a sign of the plenum?

 

The oil is normal. There will be a certain amount of oil the comes threw the PCV valve...blow by.

 

No. The plenum leak is due to a bad belly pan gasket. If you haven't changed that gasket yet, you should. Use the search function for plenum leak and you'll find hundreds of threads. Any question you can think of has been asked and answered.

 

"At the air cleaner side" as in in the air hat? If so that's either wicked bad blow by or a PCV valve that's plugged up tight.

The normal PCV air flow is through the air filter, down the hose to a valve cover, through the crankcase, up through the PCV valve, and into the intake manifold. If that air flow exists in normal volume, oil isn't going to move upstream against it.

The good news is that a blown plenum gasket would also have prevented the oil from getting there.

 

Yes by at the air cleaner side he meant the air hat. What would be symptoms from the truck of "wicked bad blow by"? The truck runs great, no "major" oil loss (about 1 qt in over 5k miles), no smoke out of the exhaust, no oil in the exhaust. Just oil residue in that one spot.

 

Try this: Take off the PCV valve, and tape over the hole. Pull the hose from the air filter housing, and plug it...... Take off the oil fill cap.... Start the engine, and let it idle, you should feel a little bit of air coming out the oil fill cap. If it is a fairly stiff breeze, you got trouble.

Next..... hook everything back up the way it should be..... leave the oil cap off, start the engine, and let it idle, you should feel a slight vacuum at the fill hole. If it tries to suck your hand into the motor, chances are your plenum is blown.

 

Thanks. Gonna pass this along to my fiance. Is it still safe to put mileage on right now? Of course we notice this while he is driving on one brake and parts aren't here yet and we are moving.