Greetings folks,
I have a 2010 RX350 and when I start the car cold the engine noise is a bit louder and different. When it warms up it goes away. Now I live in Florida so cold may not be the same as cold where you are from.
Has anyone else noticed this?
Thanks,
Ed

 

Are the RPMs higher? If that is the noise you are referring to, than it is normal. The RPMs are also a bit higher when the AC is on, so being in FL, it will be more noticeable. I speak from a general experience because RX450h has its own set of routines it goes through while warming-up.

 

I'm in Texas and we can compare weather so if ur taking about a cold start and the engine is revving a little higher for the first 30 - 45 seconds then it's normal.

 

Hi all and thanks for the replys.
I am not referring to the engine revving up when you first start. I am talking about the engine sounds different when the car is first started when you accelerate. Almost like the clicking of a valve but not quite like that. After the car warms up it goes away. I use premium gas.
Make sense?
Thanks again!

 

I notice a little bit of extra noise for the first few seconds, somewhat like what you describe.

I read something in a ToyotaNation forum that reminded me of this original question. Apparently the current generation "GR" class engine used in the RX uses very short height, light aluminum pistons (to reduce reciprocating weight) that are not perfectly circular when cold. They are designed so that once the engine is at operating temperature thermal expansion will result in optimal shape and tight match to specification. This design apparently allows the piston to move a little bit more in the cylinder creating a bit of noise until it is warmed up, and does not affect the reliability of the engine.

 

My 2007 ES350 did this. The noise was quite noticeable. I had the car for 6 years since new. It always ran great. No issues. I've noticed this noise on my 2010 RX350. But it is much less noticeable. I wouldn't be concerned at all.

 

My Wife's 2012 IS-250 is noisier at first start up when cold than my RX. The revs in the IS-250 are higher as well on the cold engine. I'm also not concerned.