82 Vette, 350 SB

Only happens when engine is warmed up. Cycles with engine rpm and happens whether at speed or car is motionless. Not A/C, Alternator, Water Pump, PS pump, or Fan clutch, or electric fan. I have pulled the belts from each in turn and squeaking is still there. It does sound like a belt squeak, but can't be.

It is driving me nuts because I cannot locate it. Cannot determine a specific location in the engine it is coming from even with the old screwdriver to the ear trick.

The only thing I can think of is maybe a cam/lifter issue. Any ideas? :banghead:

 

Is it constant or just once in a while?

I had wierd noise I couldn't figure out turned out to be a bolt came off the stall convertor and every so often the wind from it spinning would pick the bolt up and toss it around. To check this just remove the dust cover for the flywheel and stall convertor.


[Modified by Tominator, 3:29 PM 12/31/2003]

 

Constant, again, only when the engine is not cold. Real irritating. You pull up to a stop sign and people look at you kind of stuff. Pretty loud.

 

Vacuum leak at the Intake manifold gaskets. I had the same thing happen and it drove me nuts. You can use a little water around the mating surfaces to pinpoint the leak (least messy option)
That's my $.02 worth
My leak started at what sounded like a squeak and developed to a whistle after a while

 

Sounds like you have a bent henway.

 

:confused:

 

Is it a ZZ4? Known issue if the PCV system is not vented properly - it sucks air past the neoprene rear main seal. If I had not seen it myself, I'd never have beleived it ... but the local Chev dealer is who referred me to the cure.

They come with a plug in the right side rocker cover not a vent. If you have a PCV line on the left side rocker cover, it produces so much crankcase vacuum that the air comes in the rear main seal...and causes an eerie squeeling sound.
:yesnod: :smash:

 

Yeah, me too. Whats a henway or was that a joke?

Not a ZZ4 and my compression is nothing special, about 150 to 160 psi per cylinder. The intake is a crossfire. That is an interesting comment on the intake leak, I'll check on that, but kinda doubt it. It sounds just like a belt squeak, and the idle is good, not high, but right now I am grasping at about anything. I have replaced the water pump, and the PS pump and new belts trying to nail this down.

I checked the valve train last night and all is well there.

Does anyone think it could be the harmonic balancer by any chance? I had a thought about the rubber slipping and checked with a timing light last night and found it dead on 8 degrees, right where I had set it a few months ago.

 

Check out this link for yet another possiblility:
A cracked crank pulley caused my rattling/squeeking noise (pic) http://forums.corvetteforum.com/zerothread?id=438729

 

If you did anything to your valve train lately, it could be a pushrod scraping against the slot in the head. If it starts doing it when it's warm, it's because the slot gets slightly smaller, because the heads have grown, due to thermal expansion. Maybe a pushrod got bent ever so slightly causing the squeak


[Modified by 7T9Shark, 11:31 AM 1/2/2004]

 

Whats a henway? About 3 or 4 pounds depending on if its a broiler or a roaster...

 

:rofl:

 

I had one that really pissed me off and was a horrible noise. When I put my new engine in, I went with the silicone vacuum hoses instead of regular black rubber lines.

When the car got warm and the silicone got even warmer I had a shreaking noise coming from under the hood.

What would happen is the line going to the PCV valve would get warm and squishy. Then under good vacuum it would collapse, but still try to suck air through it. You know that sound you get when you SLOWLY let air out of a balloon? That high pitch squeal and noise like finger nails on a black board ? Now magnify that with the power of vacuum coming from a ZZ4 engine. It would even vibrate the hose as it would collapse and then release, then collapse and release -- holly crap was that I noise that would make you wet your paints at a stop light.

Check around that maze of vacuum lines for a sucking wound. I bet one of those hoses or connections is leaking. Some of those lines do not see vacuum until the engine coolant warms up enough to open up the thermal vacuum valves, those plastic "trees" with all the vacuum lines that are screwed into the front of the intake. Good luck - let us know what it is.

 

Woodstoc,
Just a thought.......I have the EXACT same noise from my '71 smallblock as you describe...ONLY WHEN HOT.
My squeak is from under the timing chain cover. I tried removing the belts, etc. It IS from under the cover. The mechanics stehiscope (sp) loudly verified this.
I have not as of yet pulled the cover, but check if that is where it is coming from.

 

I appreciate all the replies, including the ....ah Henway. Caught me on that one :_dupe: Got some ideas on which direction to look. Funny thing is, one of the replies point back to something I commented on a while back about a harmonic balancer issue.

I am going to find this and I will post when I catch the culprit.