I wrote a while back about a engine squeel that only appears when the engine is warm. I replaced the timing chain, serp belt and pully and tensioner, waterpump, upper intake, pcv valve, harmonic balancer, ect. It still squeels.

I found if I take the Oil Fill Cap off the squeel goes away. I replace the O-rings on the Cap and Filler Tube but it still squeels but it'* hard to determine where the squeel is coming from. The weird thing is the Pressure pulling on the Oil Fill Cap ... It feels like a Vacume cleaner is sucking on it. But when you pull the cap off there'* no more squeel.

Is this normal to have such suction/vacuume in the engine?
I think it'* not squeeling from the cap, but when I remove the cap it'* releases the vacuume pressue from squeeling somewhere else. What might be causing it to have so much vacuume? Could it be the PCV valve not working? Where would the squeel be coming from? It sounds like the rear of the motor area but it'* real hard to pinpoint. Maybe it'* causing a vacuume leak elsewhere that is the squeel?

Any help from you mechanics out there would be much appreciated .... This thing is driving me crazy!!

The car is a 95 bonny SE with 210,000 miles but burns no oil

Thanks for you help

Try the PCV, dunno how exactly it'd be doing that, but it controls pressure in the motor.

After that, maybe oil pump?

WHY WOULD THE OIL PUMP CAUSE A VACUUME INSIDE THE MOTOR?

IT'* LIKE PULLING THE OIL FILLER LID OFF A VACUUME CLEANER HOSE THAT'* HOW MUCH SUCTION IS INSIDE THE CRANKCASE.

ANY OTHER IDEAS???

You really have to find out WHERE this noise is coming from. One of those engine stethescopes would help, but in lieu of one of those, I would use a plain rubber hose near my ear and the other end wave it across the engine bay. You should be able to isolate the area of the noise that way. Good Luck and Happy Hunting.

Sorry, I don't have an answer about where the vacuum is coming from but maybe you could try something like this.


http://www.zzperformance.com/zzp/pro...alve_cover.htm

I would let the engine breath like the oil cap was off but the air would be filtered.

Well, first step would be turn the caps lock off on the keyboard. It really sounds like a PCV, or Crankcase Ventilation System (in general) malfunction from your description. High vacum at the oil filler cap is not normal.

You really need to isolate the sound at this point. Vacuum lines run all over the place and guessing is only going to be more grief.

If the body of your pcv valve is supposed to have a big o ring around it I'd make sure it'* there and in good condition.You could get a big vacuum leak without the pcv valve modulating the amount of" vacuum flow" which scavenges the crankcase vapors.Just something to check.

I checked the pcv valve and the o-ring is ok and the valve rattles. The car even has vacuume in the dipstick hole when you put your finger on it. When I pull the cap partly off the engine slows down like it wants to stall for a second before the revs come back up. Do you think it might be a blown head gasket or bad valve seals causing the vacuume to occur? I see some oil around the base of the rear head gasket.

The sound seems like it'* coming from the rear head area??

HELp!@!!!!!!

A blown head gasket would create positive pressure, unless that cylinder is not firing, and even then it would be +/-/+/-. Could a lower intake manifold gasket do this?