I just notice this behavior of my car recently (09 GS350 AWD). It usually happen in the morning when the engine still cold (Ohio winter weather 22-35 degrees in the morning). I noticed that when I let go of the gas paddle, my rpm needle dropped to about 1000 rpm and then immediately bounce back up. Is this normal??? I haven't notice this behavior after the engine get warm up.

P.S. I was driving in normal mode.

 

normal. theres several threads on this, just search "cold start"

https://www.clublexus.com/forums/gs-...rpm-spike.html

 

Normal... next question pls

 

tsiripong did you get your question answered? I have the same issue and it is different than what is described in the threads mentioned above. Have had the car for 6 winters and this is the first time it has done this. Let off the gas pedal and the RPM's DROP DOWN then come back up but DOESNT SPIKE.

The car feels like it is downshifting but not sure if it really is. Anyone else experience this?

 

2009 GS350 the first car you've ever driven?

 

Binary, your comment directed at me?

 

Completely normal. On cold mornings like that, the engine is going to be in open loop operation longer than on warm days (ignoring fuel readings from the 02 sensors and operating only on data from the Idle air temp sensors, and RPM of the engine) while it's in this mode and the engine is cold you will notice quirky things about how the engine and transmission will operate.

 

OK, thanks 2GSK...its just the first time after 6 years of owning the car seemed odd. Fifth car and none of them acted this way even when cold. Higher RPM when cold but not like this.

Also they really screwed my car up during the last valve spring recall. Either they tried to reuse a gasket or cut a gasket but I had to drop off the highway and return to the dealership with my engine billowing with smoke and oil spraying out onto the ground....so I am on the look out for any detrimental effects of that. So apologies if I am bringing up what seem to be issues within normal operating behavior.

 

No, the OP.

And by the way I had valve springs done on my car (not the recall) and I too had smoke billowing out of my car afterwards on the highway and had to bring it back as well. They blamed "whoever last changed the oil overfilled it"... which was them... but I didn't buy that excuse at all.