chsu74

I get a chattering noise, not squeal, only around 3k RPM when driving the car during cooler mornings. Once the engine warms up, it goes away. Is it a pully?

Barn996

It's gonna blow!! Just kidding. Don't know, but maybe while the engine is warming up you experience the noise and it's probably normal.

hwk72

You don't have a light weight flywheel (LWFW), do you? It does cause gear chatter under low RPM load (2.5k-3.5k) but usually only when the engine/transmission oil is warm.

chsu74

It sounds like a bearing going bad. I had a similar sound on my BMW on cold starts before I replaced the tensioner pully. It does not happen when the engine is warm. Its not consistent and only in 1st gear..

My engine is 10K miles past its life span according to some experts though.

Porx

It's gonna blow!! - - heheheh i was thinking the same ... prob normal when cold.... mine does things when cold, i cannot even explain.

Bos

Variocam maybe? Not saying it's a bad. I notice interesting habits / noises around that RPM range.

Tippy

chatter or ching?

salayc

If it's chatter, it could be the little Germans that run on the treadmill to keep the variocam in sync.

chsu74

I would not have notice it if its consistent. It only happens when the engine is cold kept at 3k rpm. Sometimes it comes and at operating temp. Perhaps I can youtube it...

Tippy

The idler pulleys will rattle/ching inconsistently.

The motor at 3k is probably at its harmonic resonance causing whatever making the noise to be more audible.

Once warmed, the metal expanding (whatever is causing the noise) causes the noise to go away.

If you can remove the airbox and accessory belt, spin the idlers and see if they are the culprit. They should spin smoothly, any crunchiness is a bad bearing.

This would be the easiest, quickest check.

chsu74

Thanks Cory! Our crappy engine lives another day.

Tippy