I have a 92 Prelude H23 with 235K km's. Recently I hear a rattle / knocking noise but only when the rpms' are between 2100 - 3500 and the car is in gear under load. Also it mainly happens in 2nd through 4rth gears. At first I feared it could be rod bearing failure but after searching throuth the archives bearing failure seems to be present at idle as well. Does anyone have any insight as to what may be the cause of the noise?

Darrell

 

Where is the noise coming from ?

 

Is the engine, tranny stock, or is it modified?

 

The engine / tranny is stock, the only work done to the motor was the timing belt changes at 100 and 200K. It is hard to determine exactly where the noise is coming from since it only happens when the car is on the road. The noise does not happen with the hood up revving the engine but it seems to be coming from low in the engine bay. As well it seems to be a fast rattle more than a knock.

 

My 4th gen has a exhaust heat shield rattle that is similar to what you explained. If you fold the rear seat down, it really gets louder. I am just too lazy to try and fix it. Get under the car and tap on different parts of your exhaust pipe/heat shield, etc. and see if you can hear a rattle or buzz.