About a month ago my 1999 dodge ram 1500 ,318, (5.2 liter) started making this whirling noise, squealing, or whistling noise deep in the motor., At first I changed out the belt thinking that was the problem, it wasn't.

Yesterday while adding oil to the engine I noticed a massive suction at the oil cap. When the cap was off the noise stopped, when I replaced the cap it started again. the same for the PCV valve, if I removed it, the noise stopped. I replaced the PCV valve, noise still loud. The same goes for the dipstick tube, a lot of vacuum, once I pull it out, noise stops.

I could not find any vacuum hose leaks, I tested and checked the air filter with no luck there.

Any help would be greatly appreciated. I have never seen anything like this.
Thanks

 

5.9 liter..dodge didnt make a 5.8

 

How is it running in general? is it really rough? Can you tell if there's any gas or antifreeze in the oil?

 

Runs fine, idles fine, oil looks clear. no engine leaks of anykind, no unusual smoking. The noise doesnt start until the engine reaches operating temp.

 

There should not be a lot of vacum in the valve cover, sounds like somethin is a little off.

 

I'd say PCV but you already changed that... The only think I can really think of that would cause vacuum under the valve cover, and to an extend the dip stick tube, would be a cracked intake runner. However this is highly unlikely... If your oil was foamy while the engine was running I'd say you might have a cracked oil pump housing or bad seal against the main cap causing it to suck air...

I just had an idea. I'll bet either your plenum or intake manifold gasket went. To check the plenum, pull the air box and look down thru the throttle body into the intake manifold. If you see a little oil there, your plenum gasket is bad. If it went out bad enough, I could see the intake sucking air from the inside of the engine and causing a vacuum effect. Same goes for the intake gasket itself. And if it's sucking air thru a small gap in the gasket, it would whine or whistle like you're describing, since it's sucking a large amount of air thru a very small space.

Have you overheated the enging anytime just before this started? If so you could have warped the intake, causing a leak. If you do change the intake gaskets, lay a mechanic's straight edge on the gasket surfaces and make sure they're still square. Go straight across, and at angles from corner to corner. If it's warped, replace it.

 

Thanks.

I found out somewhere else that if I spray gum-out or another flammable liquid like that around the intake gaskets I should be able to find the leak. I have been burning oil kind of quickly.

I have never overheated the engine.

We shall see.

 

The air that is used to ventilate the crankcase is pulled from the air cleaner area, then sucked through the pcv valve. It sounds like you have something on the supply side blocked, like the little filter inside the air cleaner housing. I have a 5.2 in my dakota and the aftermarket replacement pcv whistles. drove me crazy for a while, until I did a tune-up, replaced it with a new one, and that one whistles too.

Hope this helps

 

Hello you sound like you have A blown intake pan gasket. it is a common problem with the 5.2 and 5.9 engines there is a pan bolted to the bottom of your intake that is leaking causing an internal vacum leak and oil consumption there used to be a service buliten they also upgraded the gasket from a paper gasket to a metal one im a dealer technician and I can say that I have replaced at least 100 of them over the last five or six years

 

Is a "blown intake pan gasket" same as "plenum or intake manifold gasket?" How much does this procedure usually cost @Dealer? (thanks)