'98 S70: Screeching when Reving at Cold Start

[WhatAmIDoing]

I get this noise when cold sometimes. Goes away after warmup. I thought is was a bearing noise also. I still have the noise, and
I believe it is the oil thermostat for the oil cooler. I don't let it bother me anymore. But boy did it, when I didn't know what it was.

I feel like anything making a noise like that should be cause for concern. It's almost deafening and immediately draws the attention of everyone standing in a parking lot. How did you figure out it was the oil thermostat? It definitely seems to only occur when the engine is cold, but it's not consistent every cold start.

I'm going to try to get a good video today where you can hopefully here the noise and upload it. Also got access to some tools, so going to pop the cover off the timing belt just to make sure there's no obvious problems. Then I'll see if I can get the serpentine belt off and play with some pulleys.

[JRL]

If it's really a screetch, I can't understand why no one has mentioned the drive belt (serpentine).
That sounds like a bad or loose one from your description

[WhatAmIDoing]

If it's really a screetch, I can't understand why no one has mentioned the drive belt (serpentine).
That sounds like a bad or loose one from your description

It's not a high-pitched screech like I've come to associated with a loose belt. It sounds much more like metal on metal. But I do plan on replacing the serpentine belt if I do not find a bad pulley.

[bmdubya1198]

Is it like a low pitched moaning sound, like something is rubbing? Do you hear it loudest around the belts?

[wizechatmgr]

Whatever it is, if you're able to repair it now it likely will only be $. But if you wait it will be either $$ or $$$... Whatever is making that noise is excessively wearing during that noise.

All else fails park her on ramps a few times. As soon as you start it (with the wheels chocked and parking brake on) go under and see if you can find it from the bottom...

You shouldn't get a squeal like that from any lubrication or cooling system component

[WhatAmIDoing]

It's not really a moaning sound. It makes you cringe whenever I step on the accelerator, like when you hear nails on a chalkboard. I do not think it's a belt rubbing.

[bmdubya1198]

I was going to suggest the oil cooler thermostat. My car makes an awful moaning sound from that oil thermostat for the first couple minutes it's running in the morning.

[abscate]

Dirk...are you missing any more kittens???

[1998v70xcbill]

search other threads about "oil thermostat noise". It seems common, not easy fix on some cars. I think the oil thermostat moved when they switch the oil cooler from the radiator to the oil plan. You could try to replace. (new one could make same noise).
I have not confirmed the noise is from the oil thermostat by listening. Only going from advice from this site.

[1998v70xcbill]

thread viewtopic.php?f=1&t=62320
not sure if above link works, if not " 98 v70 noisy oil thermostat thing"