Unidentified chirping/squealing noise from engine area.

[Jonas]

Hi all.
2009 Pontiac Vibe GT (Toyota Matrix) 2.4l
The sound is intermittent and I thought it was my AC compressor, but I bypassed it with a shorter belt, but it didn't work.
All the pulleys spin freely and quietly by hand.
It sounds like it's coming from the top of the engine/exhaust manifold area.
Any ideas?
Thanks.

 

[martinq]

Sounds like a vibrating exhaust shield or maybe from the belt (slipping, bad bearing).

How does it change with engine speed? Does it go away?

 

[Jonas]

I can't tell if it changes with engine speed. I can only hear it at idle or when I'm taking off from a stop or coming to a stop. It comes and goes too. I just drove around for a while and I didn't hear it most of the time. Sometimes it sounds more like a rattling or tapping noise than a chirp.

 

[ka9mnx]

Idler pulley.

 

[D60]

Ok I'm not sure this is belt but start it with no belt and that'll answer that question.

I've seen rattling heat shields make some horrific noises, but can't say if that's your issue here.

If you can access the oil pan see if preloading the engine with a floor jack affects the noise. That might give a clue to something like motor mounts/exhaust positioning etc

 

[D60]

Since I don't actually know anything and would be absolutely screwed without web access, this guy says flexplate. Is this an auto?
https://carkiller.com/scottykilmer/qa/2009-matrix-1-8l-tic-tic-tic/

edit: didn't realize this is somehow affiliated with Kilmer. My apologies to all (and the world!)

 

[KrisZ]

When the engine is cold, remove the accessory belt altogether and start the engine. You will know right away if the noise is accessory/belt related or not.

 

[D60]

This guy talks of heat shields and shows some in a vid, but located further back on vehicle
https://www.toyotanation.com/threads/2008-matrix-rattling-noise.1529994/

 

[Jonas]

Since I don't actually know anything and would be absolutely screwed without web access, this guy says flexplate. Is this an auto?
https://carkiller.com/scottykilmer/qa/2009-matrix-1-8l-tic-tic-tic/

edit: didn't realize this is somehow affiliated with Kilmer. My apologies to all (and the world!)

It is an automatic. The video was unavailable, but the description matches mine closely. It's quieter when I put my ear near the belt, pulleys. I'll check underneath that area, thanks.

 

[Jonas]

When the engine is cold, remove the accessory belt altogether and start the engine. You will know right away if the noise is accessory/belt related or not.

That's not a bad idea, but the sound is intermittent. Yesterday I drove around for about 30 minutes until the sound came back. I will try it, though, and report back. Thanks.

 

[Jonas]

*Update* I degreased all the pulleys (they were dirty) and re-installed the belt. I got the squealing noise around 1000 RPM, then it stopped, but this intermittent clanging sound started. There is still a hint of a chirp in the background. It seems loudest from the front exhaust manifold area and has a ringy, resonant sound. Maybe broken catalytic converter?

 

[Jonas]

*Another Update,* Water pump went out. Coolant temp got up to 237 when I got home and there was coolant slung all over the engine bay. I found a video of a Camry making the exact same sound. At least I know what it was now!

 

[D60]

It is an automatic. The video was unavailable, but the description matches mine closely. It's quieter when I put my ear near the belt, pulleys. I'll check underneath that area, thanks.

And what came of the possibility of the flexplate?