Olds 350 making noise

[Dragoon]

Hello,

I have a really annoying noise from my olds 350 engine. It sounds like when belts are slipping, so I began with tightening the belts - no change.
The next step I made was to renew both belts(alternator & power steering) and changed all pulleys, still no change in sound.
Then I removed both belts from the engine and ran the engine without them, still the same belt squeal noise!
I called a mechanic but he had no idea what it could be.
Does anyone know what could cause this annoying noise and is it dangerous to drive around with it?
The noise is not there when the engine is cold but as it gets warm it slowly starts.

 

[peteyb]

How about a vacuum leak? Check the seal around the base of the carb.

 

[Dragoon]

I'm pretty sure it's not coming from the carb.
The noise seems to come from the crankshaft area.
It sounds like something is not getting enough lubrication.

 

[MrLightning]

I'm pretty sure it's not coming from the carb.
The noise seems to come from the crankshaft area.
It sounds like something is not getting enough lubrication.

whats the history of the engine in question? Have you had it long? did it come in a car you recently bought? Your description of a noise that sounds belt related, (then describing it as a possible lack of lubrication in some area) is alarming! The sound I typically attribute to a belt, (squelching) would DEFINITELY make me DO IMMEDIATE engine tear down or further engine diagnosis, based on it making same noise and having no belts on it. You may have already done, or have some type of damage to the engine as of now, if what your describing is still present and typical sound would go away with belt tightening. Are you able to post a short video or sound byte? Noises are VERY hard to describe and sometimes are very hard to eliminate. Dealers will even tell you that when customers are trying to describe a particular noise and or origin of a noise, that they have a hard time, because the noises have a tendency to sometimes come and go.

 

[pontiacgp]

I would remove the torque converter bolts and pull it back to inspect the flex plate for cracks. If the flex plate is good then start the engine without the torque conveter connected to see if the noise is still there

 

[olds307 and 403]

Very strange. I actually had an Olds 350 knock at idle and sound like a table saw accelerating. Turned out the torque converter dust shield was twisted causing the noise. As long as your oil pressure stays the same, it should be okay to drive. I would inspect the whole car top to bottom first before any long trips.

 

[Pontiac455]

Sounds like a overlapped insert to me.

 

[Dragoon]

I'm pretty sure it's not coming from the carb.
The noise seems to come from the crankshaft area.
It sounds like something is not getting enough lubrication.

whats the history of the engine in question? Have you had it long? did it come in a car you recently bought? Your description of a noise that sounds belt related, (then describing it as a possible lack of lubrication in some area) is alarming! The sound I typically attribute to a belt, (squelching) would DEFINITELY make me DO IMMEDIATE engine tear down or further engine diagnosis, based on it making same noise and having no belts on it. You may have already done, or have some type of damage to the engine as of now, if what your describing is still present and typical sound would go away with belt tightening. Are you able to post a short video or sound byte? Noises are VERY hard to describe and sometimes are very hard to eliminate. Dealers will even tell you that when customers are trying to describe a particular noise and or origin of a noise, that they have a hard time, because the noises have a tendency to sometimes come and go.

I bought the car last year, it had then being out of traffic for almost ten years.
The transmission was broken when I bought it so I replaced it.
I changed the engine oils and filter before I fired it up..
Last year I didn't even drive 20 miles with it, just to Inspection and home again.
No history whatsoever about the engine unfortunately.

I'll see if I could create some kind of video of the noise.
Thanks for all the answers, I will try to further investigate when I find time for it..

 

[MrLightning]

[quoteI bought the car last year, it had then being out of traffic for almost ten years.
The transmission was broken when I bought it so I replaced it.
I changed the engine oils and filter before I fired it up..
Last year I didn't even drive 20 miles with it, just to Inspection and home again.
No history whatsoever about the engine unfortunately. .[/quote]

WOW! that's a huge chance to take! a motor that hasn't been run in 10 years and all you did was change the oil? I think theres your problem! I would've pulled the pan off at a minimum and spun the engine over several times and took a LOOKSY!

Good Luck! id say you should be pulling the pan now for interest sake if for no other reason.

 

[shanghaismith]

Check your harmonic damper. I had one come apart and it made a squealing sound.