Hello everyone, my wife has an 01 IS300 and an interesting issue. Her engine rattles...not valve tick but rattles at idle. Once the car is driving the engine is fine...no rattle at all. I listened to the noise and it is coming from the top part of the motor just below the intake manifold (middle of the engine)

To be honest, this one has me completely stumped because as soon as any rpms above idle are provided...the car is quiet and drives fine.

Has anyone come across something like this? The rattle is very loud and I checked over all the components in the engine bay and nothing seems to be loose. Any help is appreciated!!!

Thanks in advance!

 

What is your mileage? Is it under warranty?

Does the rattle sound like something loose and moving around?

 

The IS has 82K so the warranty has expired, it sounds like a rattle "under" the motor if that makes sense. It drives completely fine, the rattle only occurs at idle which is odd. I jacked the car up and removed the under panels and could not see anything loose.

Honestly, this one has me completely stumped! Any ideas or places to look are welcome!!

 

Could the noise be coming from the catalytic converter ... pound on it with your fist and listen for rust chunks.

Sometimes you need to lift with ramps or jack stands to crawl under for a listen.

 

Turns out it spun a bearing in the bottom end. I hope this isn't common...I'm honestly in shock...I figured these motors to be solid for at least 200K.

Anyone else have major motor problems? This is the first time in any car that I've had this happen.

 

Good suggestion, we checked that along with all the belts and tensioners...even went as far as checking the stall converter and removing the transmission!

After everything was done...the noise was confirmed to be the bottom end

I hope this was a fluke!