LT4mula

Hi All.
I recently got a 600. On cold startups there are times when it makes a horrible clanking sound when it does its ~2 second low idle. The instant it goes to high idle the sound goes away. After the car has been run, I don't hear the sound again until the next cold start.

This is not normal injector click, and if it is valve click there must be a side issue causing it. Like an oil primer working intermittently or something.

Has anyone heard of this?

https://youtu.be/0SNiElOEjas

JiffyPop

Wow that sounds like a valvetrain noise to me. Did you check to see if the valve spring recall has been completed on the car? You can check the service record from previous owners on the mylexus website

LT4mula

It has been to the dealer with me for an emissions recall. I figured if there were any other open items that they would have done them. Maybe no?

Also, I thought the recall was for broken springs... this doesn't happen on every start up. I recorded 4 cold start-ups before getting the sound to surface.

davisk

Could possibly be low oil levels? Viscosity of the oil? Possibly the crank shaft picking up the cold oil and once it gets going and lubed the noise goes away would be my guess.


Just throwing things out there that can easily be ruled out.

jmcraney

"Piston Slap" could be causing the noise that you are experiencing. Most mechanical experts regard most piston slap as innocuous - just a noise that usually goes away after the engine has run a little.

LT4mula

hrmmm. I guess another thing I should note is that this is a very digital situation, meaning: it either does it very loud and obvious, or not at all.

Is there an electric oil pump that is supposed to fire up before startup?

Nospinzone

I would agree with davisk in that it is some kind of lubrication problem.

Jim, I don't think its piston slap, at least as how I know piston slap. It means there is too much play between the piston rings and the cylinder. I have had this situation and it only gets worse, particularly at higher speeds/revs. The only solution is to rebuild the engine to spec.

stopdrpnro

did you ever find a solution or answer to this?? My 600 did the exact same thing on random cold starts