Need help! I have a 02 AP1 with a used motor from japan. Milelage on motor is unknown but assuumption was less than 50K. I owned the car for 2 years and put a few track days. Most recently, during my recent oil change, my friend noticed a rattle noise from my engine.

At first, we thought it maybe a spun bearing, rod knock but checked the oil pan and didnt see any metal. Since then, I took my car into a local shop and they recommended to change the water pump and serpentine belt. It didnt make a difference and car is still making the rattle.

The rattle/sound only happens when the engine is cold and stops after engine is warm. At warm starts and warm engine idle and driving, there is no sound at all. A few folks have now said it might be the TCT but from my research, it looks like the TCT only makes sound when the engine is warm not cold and usually, when a TCT fails, the sound is so obvious, you know that's the problem.

Anyways, wanted to see if anyone had any ideas? I checked the forum history and found someone with the same issue but no one ever replied or resolved his question.

Thead here: https://www.s2ki.com/forums/s2000-un...-cold-1193509/


Ideas? Any help well appreciated.

Thanks,

 

Its stupid easy to rule out a water pump or other serpentine belt driven accessory. Just temporarily remove belt, see if noise goes away. If it does, its one of the pullies driven by belt.

While belt is off, spin each pulley by hand. Make sure all spin smooth, no noise.

Obviously don't drive or let it run long enough to overheat with belt off.

Water pumps almost never fail on these engines. Mechanic is an idiot, as it'd take him 5 min to know it wasn't water pump.

 

Sounds like valve train,have you checked valve lash&checked for broken retainers,what oil are you using.

 

I had a shop do a valve adjustment 3 months ago and also swap retainers from AP1 to AP2. Currently running Costco 10W30E which I read is just Mobil 1. Before this recent oil change, someone did mix my oil with Motul 5w40 8100 because i was very low between sessions at a track day.

I forgot to mention, I run aftermarket non OEM motor mounts and my car vibrates pretty harsh if that information might help.