Cold Start - Fast Idle

[Pac Man]

Hi all,

Could some of you please advise what your cars fast idle speed is on first start up when left over night and is it instant or delayed as I would like to reference against mine

I would guess that diesels may be different?

Thanks

[toffee_pie]

mine is just about 1k when i start up and settles to circa 700... ish once warm, A/C is on pretty all the time for me

[steveledzep]

Depends on the ambient temperature. When 0 degrees or below, mine would start at about 2000rpm, then blip to 2200 before settling to about 1500. Once driving, would quickly settle to a tickover of 750rpm(ish).

In the recent warmer weather, it has been starting at not much more than 1000rpm and going to tickover very quickly.

[Steve_M]

Hot or cold weather no difference, Climate control on 1200ish. Climate control off 7-800ish.

This is on a diesel.

[Pac Man]

Ok so mine this morning kicked in at 1600 rpm this morning a little lower than normal but found the same margins as the above 2 - I just find it little excessive, I would expect a fast idle of 1200 even on the coldest day.

I sort of cringe when I cold start as I know that most engine damage (even though very minor) is done from cold start due to oil drain over night or longer from splash Fed components.

I know there are oil gallery return valves usually fitted in the oil filter housing to prevent total oil drain but you can't protect everything.

My Car is in for fuel pipe recall tomorrow I might try and Grab a lexus technician and ask if the fast idle parameter in the engine ecu can be modified locally at dealer level, although I fear it might be a vehicle file 're write which would require it being carried out at manufacture level which would be the same as the vehicle manufacturer as I work for - this is a pain as you have to extract the vehicle file for that specific chassis 're write and up load to central systems ready for the dealer to upload . Manufactures want chapter and verse why the vehicle would need this , and usually things like this are done for a very specific reason- oh well.I can try

[toffee_pie]

cold start

normal mode

[koppatroppa2002]

Mine its 1200 spot on @ cold start then 800 spot on again after @ 30-60 seconds. If its warm outside, it'll be @ 800 straight away @ cold start.

If the revs are 1500 or higher, i heard that the DPF is cleaning himself ( after loads of short drives or city drives) and again, i heard, that it's good to take it to long motorway drive (200miles or more) to help a proper clean!! Read some reviews about this high revs at cold start and most of the peoples tend to panick! It is just a normal procedure for auto cleaning of DPF which by the way, everyone at Lexus fail to inform!!

Good day.

Another thing: - 2000 revs at cold start? That's way to high. Deffo something fishy there / sorry about bad news :-P

[koppatroppa2002]

And just popped out one more thing in my mind: Its not recommended to have any electrical on at cold start, especially AC. It's inefficient anyway as the engine it's cold so the whatever settings are for temperature, are equal to nill/zero. Even in the Lexus manual is specific stated to avoid short time switches of AC (less then 5min) + to not mention the Battery also.Its obvious that at cold start the engine, fuel pump, senzors, computer, all pumps, alternator etc needs power!! By having autolights, radio, AC, navigation On, it will only do more bad for sure, then good. That's just me anyway.

[toffee_pie]

I think that is nonsense tbh, my car has all the electricals on and it starts bang on and has done so since i got it. What does the manual say about a/c i have not seen anything.