jajuelson

I have a 1994 ES300 with the 6 cyl. 1mz-fe motor, in the past I have changed the fuel injector for #1 and also the knock sensor, car was running great. Started it this morning and it sounds like something is rattling around the top of the engine, not always though. It varies where the sound is, but mostly sounds like it is in the air intake, but sometimes in the front lifters, it is definitely not a lifter tick, it sounds like a ball bearing in a tin can.

morphh

It could be the the water pump bearings, did u replace it when u did the timing belt?

morphh

It could be coming from the bearings in the water pump.

jajuelson

I didn't break the engine down that far, just took the air intake off and manifold, it is a real odd sound that I haven't heard from an engine before. It will increase when revved up but is not always present. No noticeable lack of power except when in park occasionally will stumble after revved. Seriously sounds like a loose piece of metal bouncing off the lifters.

PFB

These are long shots, but at least are easy to check, and are quick to perform

1) Maybe the baffle inside the valve cover, just below the oil filler cap disintegrated, and parts of it, or all of it fell inside the valve cover. Remove the oil cap and check It.

2) A disintegrating PCV valve is another possibility. Easy to remove and check.

An audio recording would be helpful.


Phil

morphh

MIne does the same i have a 94 es 300, i believe it is the ACIS when it ingages its rattling around, it has to be reset by screw on side