Found an old thread that says "98% sure" if the engine knocks when you let off the gas, you have rod knock.

Is that true, if it only occasionally happens, typically when hot out, and if you just partially let off the throttle?

Thanks.

 

It could be rod knock caused by slightly worn bearings or piston wrist pins. Try a thicker oil and see if that quiets it down. If it does, then I'd say the bottom end is just starting to loosen up a bit. Could be time to rebuild it before any damage occurs.

 

Actually, it's a friends car and he is going to trade it in for a 2K3 Maxima. Mostly because of that noise and because the engine has 98K on it and the warranty runs out at 100K plus the sunroof died and will cost him $1500 for the dealer to fix or just trade it in and the dealer will eat it.

Just wondering if that was truely rod knock, since he seemed to already know that's what it was and I had never heard of that happening on the overbuilt VQ. Who knows what abuse it has seen though.

Thanks for the confirmation.