600 owners,

Anyone experienced loud engine grinding noise accelerating from stop when you first start the car? It is right after cold start, lasts 10-15 seconds until I get to 30-40mph. Engine sounds normal otherwise.

Appreciate in advance sharing your experience!

Edit: 2008 LS600hl with 28K miles

 

This does not sound good. Cold starts are when most wear happens to the engine. get it checked out.

 

There are all kind of cold engine sounds especially with these newer engines that use timing chains and some of the bucket over shim valve trains and VVT. I too have noticed mechanical sounds with the LS460 (similar designed UR engine) on a cold start that goes away in about a minute of operation. It's not too noisy but noticeable even with the cars that I have test driven before I purchased mine even one that had only 9k miles on it.
It could also be the difference of the fuel injection switching from port to DI. I believe this is also the result of the light weight oil starting out thin and then thickening up. There will be some metal to metal noises however it should not not increase any wear from the norm. It's not the most pleasant sounding engine on cold start but it shouldn't effect it's performance.
Never the less it wouldn't be a bad idea to have it looked at.

 

Does it sound like a (typical?) ICE noise or do you think its coming from the electric motor?

 

I don't hear this grinding noise before I drive the car. Engine idles fine right after cold start. The noise is heard right after I accelerate and is gone by the time I am at 30-40mph. Never comes back except after another cold start.

This leads me to believe that this might be from the drive tain