So ... soon after I had the battery cable replaced I started to hear this weird, short duration engine noise - only cold starts. Lasts only 2 seconds. Sounds like something is making a grinding noise as it spins up, and then stops completely. Its not a high pitch noise.

I thought it might be an idler / tensioner pulley going bad but they seem ok to me. I removed the belt and spun them and although a bit free spinning I did not hear bearing noise. I did notice this clanking noise from the power steering pulley as I sun it back and forth - did not seem right. I tried to upload a video clip I took but did not work.

 

You'll need to upload the video to YouTube then put the link here.

What you describe as a grinding noise for a couple seconds just on cold start up is a textbook sign of a lazy chain tensioner that should be fixed/replaced immediately. That noise is a slack chain being dragged across the plastic tensioner pad and once worn through will contact the metal tensioner paddle itself. The tensioners are a combination of spring tension and hydraulic oil pressure. If the internal seal wears, they don't hold pressure when the car is shut down and you get this phenomenon until pressure builds up again from the engine running, but that start up noise and wear to the guide is bad. Have you found any black or brown plastic bits in your oil filter media?

It could certainly be something else, like a worn pulley, but because of the danger if it is a tensioner, it nerds to be checked out now.

The Bank 1 and IMS tensioner aren't very hard to do, but you do need to lock the engine at TDC to do them properly. To do the Bank 2 one, you have to remove the air conditioning compressor.

 

I finally was able to upoad a video of the noise I am concerned with. It sounds like its coming from the starter? The noise continues after the pulleys stop rotating so I can only think it is the starter winding down. Once it starts the noise goes away. And only after engine is cold and has sat for over a day.

Any help witt diagnosis will be greatly appreciated.

 

I have a pretty similar sound. It's also intermittent. I think it's the starter gear engaging too long with the flywheel. I'm pretty sure I have the original starter. They don't last forever. Not sure how to confirm it's the starter before just replacing it.

 

That sounds like the thrust bearing on the starter is toast. After the starter solenoid pulls away from the flywheel and is unloaded, you are hearing the spin down of the motor with the bearing vibrating. I am not sure what the long term implications are, but my guess is either it won't engage to start the car, or worse, it won't disengage after starting it.

 

Based on the video, I am thinking the starter is your problem as well.

 

Thanks for all your replies.

And so it is the starter. Confirmed by several Youtube videos with exact same noise. Lazy release spring mechanism. I think I will wait before I replace the starter since not driving much now while working from home. Plus I just paid to replace the starter cable 2 months ago. Should have replaced the starter then. I think I will tackle the starter myself later on.

But kind of disappointed with the many unplanned maintenance events with this car. It is 14 years old alright but only 55K miles. Premonition ??