Cold Start Engine Knock, What Is The Cause?

[DWD1010]

Does anyone know what is the cause? The sound is like valve train noise (lifter,valve,valve spring).No one has identified where the noise is coming from?

Just purchased a certified 2007 RX 350

In the morning on a cold start there is a distinct engine knock. It diminishes as the engine warms up but never fully goes away.

I have had the vehicle to Lexus service. They tell me this is normal (The nature of the beast). Does anyone have a fix or a service bulletin that addresses this problem.

[scottq60]

Does anyone know what is the cause? The sound is like valve train noise (lifter,valve,valve spring).No one has identified where the noise is coming from?

Just purchased a certified 2007 RX 350

In the morning on a cold start there is a distinct engine knock. It diminishes as the engine warms up but never fully goes away.

I have had the vehicle to Lexus service. They tell me this is normal (The nature of the beast). Does anyone have a fix or a service bulletin that addresses this problem.

Yep...it's "normal" per the dealership. My wife's '09 has done it since new and the '10 loaner they gave us when hers was in for a recall (oil line replacement), did the same thing.

Personally, we're just gonna drive hers and forget about it. Otherwise, it's been near perfect...a pleasure to drive year-round.