no rattling, just a squealing, by the time i open the hood the noise has stopped so i cant find the source

Will the squeal resume if you race the engine a little? You can race it right at the throttle body. Don't over race it, but just give it a little tap.

Also, will it do it when the car is in drive, but with your foot on the brake? If so, have a buddy hold his foot on the brake while you inspect the pullys for noise.

semms to be a moot point now, the sound seems to have stopped, but to answer your questions, no, revving the engine or keeping it in the drive with the brake dont seem to help, ill try gaian if the noise comes back but for now its fine

Hey, NERV, just for the fun of it, do this: With the engine idling, remove the oil cap, and see if you notice a "sucking sound." (-it will only last a second or two)

-to do this test, it won't matter whether or not it is making the squealing noise.

Let us know.

Thanks

i assume there is a decent amount of suction because when i went to remove the oil cap it didnt wanna come off, i didnt wanna pull hard cuz i tihnk i might break something so i never actually got it off, but it feels liek there is plenty of suction holding it on

Well, NERV, you have discovered a REAL PROBLEM: There should be ABSOLUTELY NO SUCTION AT ALL in your crankcase.

There was another topic (-or two?) just recently on exactly that same problem.

They discovered that there was an O-ring missing on the PCV valve.

That is the very next place I would check. (-and I would do it very soon)

Once again, just to re-state, the reason you are or were, hearing a strange squealing sound, is that air (at atmospheric pressure) is trying to find anyway it can to squeeze past gaskets, crankshaft seals, and where ever else it can find a way into your engine. Several years ago, I had an engine in which the fresh air return for the PCV circuit had become blocked, and it made the strangest sort of howling/honking/squealing sound as air was forcing it'* way into the engine at the front crankshaft seal.

thanks for the warning, ill investigate asap

Hmm i got suction at my oil filler port too! I thought that was normal! NOOOOOOOOOOOOOOOOOOOOOOOOOO

On the up side my PCV grommet is sorta destroyed but i put RTV on it ~2 yrs ago to be sure it was sealed... also when i open the filler cap and take it off the car stalls slightly (but stays on). How come there isn't supposed to be vacuum in the valve covers? My valve cover (i'm driving an '87 bonnie) has a tube going to the air intake hose which I assume would lead to vacuum at the valve cover.. the tube is pretty huge too..

Mike diaz

Mike Diaz, I can’t say specifically about your engine. But on my ’99 Bonneville, non-supercharged, there are two O-rings in the picture here: The upper O-ring provides a seal for the MAP sensor, which lives in the same housing. The PCV valve, underneath the MAP sensor, also needs it’* own O-ring. (It goes around the body of the PCV valve, just below the flange).

Nerv, When the PCV valve O-ring is missing, serious amounts of vacuum leaks around the valve, making the “crankcase purge rate” WAY TOO HIGH –in fact it over-powers the PCV “fresh air return path.” At that point vacuum is present through the crankcase, and air then leaks into the engine at points of least resistance. –Most likely, around both crankshaft seals. (They are “directional/lip seals,” which offer high resistance to oil (and/or crankcase pressures) escaping from the engine, but offer very little resistance in the opposite direction.

Here is something not too pleasant to think about: Along with the air going into the engine past the crank seals, goes whatever amount of black dirt, grit and grime that may have accumulated outside the seal. That thought makes me shudder.

Mike, in the interest of not “hogging up too much space” here, I can send a personal message to you, explaining the PCV system.

Once again, to everyone interested: YOU SHOULD NEVER HAVE VACUUM INSIDE THE CRANKCASE. Engine manufacturers could just as well use a small air pump to purge the crankcase, but using intake manifold vacuum is much simpler, and actually is a basic design carried over from the 1940'*, when GM first used "positive crankcase ventilation" on engines in military trucks.

Thanks to all, Harry.