OK, I'll try my best to explain this. My Bonneville has started making a screeching or squealing sound. The funny thing is, it doesn't appear to be a belt or the brakes. When I start the car it seems to make this sound and after I take off and start driving it goes away. But when I hit the brakes it comes back and seems to get louder the harder I hit the brakes. And when I let off the brakes and give it gas it stops again. It doesn't seem to be the brakes squealing because if I stop and put the car in park it will continue the squeal most of the time. Today while it was "squealing" I opened the hood to try and pinpoint where the sound is coming from. It doesn't seem to be coming from the belt. It seems to be coming from the front or maybe even the back of the engine where the tranny is attached. I thought it might possibly be a loss exhaust vibrating but I'm unsure. It seems to squeal pretty good. What could this possibly be? It gets worse when the brakes are applied but still does it when the car is stopped. When the car is warmed up it doesn't do it quite as bad but seems to be getting worse. I would relate the sound to a belt squealing but it just doesn't seem to come from that area and it quits squealing when I give it gas and drive. Any ideas what this might be?

When was the last time you messed with your PCV?

Have you tried pulling your oil cap at idle while the sound is happening? Try it. Tell us the results.

I haven't done anything with the PCV. I have only had the car a couple months. And I'll try pulling the oil cap today and get back to you guys later tonight after work.

I had a squeal last summer that got louder with the brakes but it also seemed to squeal in park and go away driving, and i'd hear it on sharp turns too. Ended up being a combo of the brake pads being worn out so the squeal tab was hitting the rotor, and low power steering fluid.

It wont hurt to check both of those as well, simply opening the cap to the power steering fluid, and pop the wheel off to check the brakes pads.

Hey that'* my line!

I'll check that out but it just doesn't seem to be coming from that area.

I checked it today by taking off the oil cap and nothing happened. The noise stayed the same. Didn't get louder or quieter just stayed the same.

Ok, I'm not sure where exactly the pcv valve is at. Is it on top of the engine toward the drivers side? I see what I "think" is the pcv there with vacuum lines coming out of it. There is a line that runs down to a canister that appears to be maybe something to do with the master cylinder. I think I remember seeing a vacuum line running from this canister to the master cylinder. This canister is located about between the engine/tranny and front wheel well. Is it possible that the vacuum lines or the anti lock brake system may be causing this squeal? This canister seems to be in an area thet the noise "may" originate.

Canister? Lets see...what are the things in that general area that may resemble a canister.

You've got the fuel vapor/charcoal canister that is in front of the strut tower/under the airbox, that has vacuum lines going to it...then you've got the transmission shift modulator in front of the engine and transmission lower down that has a vacuum line going to it...and then you've got the cruise control servo directly under the master cylinder, directly in between the strut tower and engine.

could you please take a photo? that'd help alot.

and as for your pcv valve, its VERY easy to get to.

it is located on the passenger side of the upper intake manifold...

anotherwords... riiiight...

Here (excuse the filth)


As noted, under the cover. Its a round depress and twist to remove type thing. Make sure to replace exactly as found, paying close attention to the o-ring(*) This should be done every 30k fyi.

Ok, arrow number 1. points to what i thought might be the pcv. Looks like that is wrong. However arrow number 1. points to the thing that has vacuum lines coming out and one of those lines goes into the "canister" that I was referring to.

Arrow 2. is pointing to the area the "canister" is in. It is underneath that stuff and seems to be obstructed under the radiator hose in your picture. I only brought up the canister as a "what if?" though because I'm unsure.

Sorry that I don't know the proper names of these parts. Also, sorry for my sad attempt to draw arrows with photoshop. haha

The arrow for number 1 looks like it'* pointing to a part of the throttle body assembly. I'm not sure about the canister you're talking about, but the master cylinder is just under the strut bar. if the squeeling is coming from low in the engine bay, maybe it could be the boot of your driver'* steering assembly? in which case I may assume some kind of problem with power steering (but I believe it wouldn't be a pump problem, as the pump in on the opposite side of the engine... from waht i've learned in the last few days anyway)

Anyhow, what do you mean by this? It should just be checked or should we replace something there every 30k?