350Dave

This morning, my "cold" engine - overnight low 55 outside, about 75 in the garage where my 350 was parked overnight, ran at a fast idle 1500, then down to about 1200 after 20 seconds or so. I did not want to cause tranny clunk, and put my foot on the gas pedal to 'clear its throat' - it retuned to 1200. I then put it in 'R', and at 1200 there was no clunk whatever. This is the first time I have seen an initial idle speed this high, also was the coolest morning since I have owned the car. Any comments?

carbuff

"55" . . . I can only dream about that temperature. This summer we have had 101 consecutive days of 100F+ and 32 days of 110F+ here in Maricopa County.

In this blistering heat, my ES350 has run like a champion. I am thankful that it has such a great air conditioning system.

MD350

I have owned mine for a year and have had the car in below freezing temps. Yes, mine does that too. A few times, the fast idle might have been even higher. I would not worry about it.

amf1932

This is very normal. The idle speed is determined by the engine management system(ECU), which takes into consideration, ambient temperature and coolant temperature.

LexBob2

Plus, all newer cars idle faster at startup to get them up to operating temperature faster, for improved emmisions.

amf1932

A faster idle in a cold engine started many years ago in cars that had carburetors......this isn't a recent phenomenon.