runningox

2004 RX330 FWD 68Kmiles
When initially start from cold, runs at about 1400 rpms for first minute, then slowly drops to around 700-900. This only happens once everyday morning? Do I need to check or fix something?

Thanks.

ggebhardt

Sounds like it is just upping the RPM due to the engine being cold. If it only does it from dead cold in the morning and never any other time, it is likely normal

jfelbab

Really has not been all that cold here in the past week or two, at least around Cape Coral. Mine doesn't do this but it's been in the low 60s in the morning. If you wait a bit, the next couple days will definitely be cold in the morning (low 40's) and the higher rpm would be expected for a minute or two.

triplecore

Mines 4wd does that to dont worry. In the cold the RPM is always higher in all cars. Do a test drive it till the engines Temp is in the Middle the normal temp shut it off and start it back up after a few minutes. I bet you have to look down and see if the car is running because it started so smoothly.

Grumpa72

That sure sounds normal to me. My 2005 RX does it, my 2007 BMW does it and my 1993 Acura does it.

The basis behind this is that the most polluting time for an engine is when it is just started, cold, and idling. So the manufacturers found out that they can increase the rpm a bit to speed up the cylinder temperature warm-up which helps reduce start up emissions. That is also the reason that it is a terrible idea to start up your engine, let it idle for a few minutes and then drive away. Most modern vehicles should be started and driven within the first few seconds. The obvious add on is to limit rpms until the engine parameters and temperatures are normal.

Gary