Revs On Cold Startup

[ClutchBurndout-:(]

ok its been worrying me a fair bit lately, it dosent take a genious to understand that on a cold engine there is no oil around the engine on a cold startup, so on that note, just a quick question, is the car meant to run at higher revs on cold startup then as it gets warmer the revs come down? it almost brings a tear to my eye when i start the car up in the morning and it revs its tits off and slows down.

is this normal?

[Kaz200]

whats it sitting at on startup? 1300ish or are you talking higher than that?

[Timeb0mb]

every injected car iv had does that, i think its the fuel choke.

as long as its around 1300 ish as mentioned above its completly normal

[ClutchBurndout-:(]

well it revs to around 1900 for about 2 seconds when u first turn it on, then it slows to around 1300 1400

[blind_elk]

It should have oil at the top of the engine before the engine even fires (just on cranking), so no need to worry about the higher revs at cold start.

[pablo101]

its fine

it does that so it warms your car up quicker

[paulr33]

the longer the engine is cold, the worse the performance, economy and emissions are

the engine's ideal operating temp is 80deg so it does everything possible to heat itself up to 80deg

so below 80deg the ecu adds in fuel and ignition correction to get to operating temp quicker

[assyrian4evaa]

the longer the engine is cold, the worse the performance, economy and emissions are

the engine's ideal operating temp is 80deg so it does everything possible to heat itself up to 80deg

so below 80deg the ecu adds in fuel and ignition correction to get to operating temp quicker

paul on that comment, are you saying that the longer it takes the engine to warm up to operating temp, the worse it will performe etc.? as in for best performance and economy (at operating temp) its best to warm the engine quicker?

[paulr33]

its better to have the engine warm up as quickly as possible, the best way to do this is drive it around normally but dont trash it

tactics such as leaving an engine idle for a 5 minutes before you take off for work is bad, as engine runs colder for longer than it normally would

so drive it around, just dont trash it till the engine temp is up near 60-70deg then its ok for some normal load etc

i usually just baby it around for first few minutes by the time im near the freeway entrace the water temp is well past 55deg so its fine after that

[Charles89]

its better to have the engine warm up as quickly as possible, the best way to do this is drive it around normally but dont trash it

tactics such as leaving an engine idle for a 5 minutes before you take off for work is bad, as engine runs colder for longer than it normally would

so drive it around, just dont trash it till the engine temp is up near 60-70deg then its ok for some normal load etc

i usually just baby it around for first few minutes by the time im near the freeway entrace the water temp is well past 55deg so its fine after that

what happens if you do happen to trash it when its cold? does it wear out the engine more?

not that I do it

[Phatboy]

Yeah it does wear out the engine more, similar to revving it while still cold when you start it. When it is warm the oil has had time to not only disperse around all the parts, but to reach a nicer viscoscity for engine protection.

[ClutchBurndout-:(]

i used to have a VH commodore, and when starting, would have to apply 50% (keep the engine running) tactics, and 50% (not let it die) tactics, so naturaly the lower the revs the better in that case, because it had no oil at the engine when starting. thats why i asked

[r32line]

An idling engine below 2,000rpm is doin far less damage then when you first pull away and change gears at prolly 3,000rpm+ with the engine under load... So I would not shed a tear on startup, just dont rev out the car at all in the first 10mins... It suprising how long the oil gauge takes to rise... made me realise how useless the water temp gauge is!

Edited May 27, 2008 by r32line

[ClutchBurndout-:(]

An idling engine below 2,000rpm is doin far less damage then when you first pull away and change gears at prolly 3,000rpm+ with the engine under load... So I would not shed a tear on startup, just dont rev out the car at all in the first 10mins... It suprising how long the oil gauge takes to rise... made me realise how useless the water temp gauge is!

so your saying its better to let the car warm up in idle for 5 mins?

[dezz]

so your saying its better to let the car warm up in idle for 5 mins?

No, it's not.

Everything else will be stone cold if you leave it idling for 5 minutes...Start it up, wait about 30 seconds, then drive off keeping the revs to a minimum, and everything (gearbox, engine, diff etc) will all warm up

[ClutchBurndout-:(]

wow, this goes against everything thats been told in the past, if you ask anyone they will say let your car warm up for 5 before driving, why has that been the case all these years and then someone says its bad? surely it must be better to let it idle for 5, otherwise how did everyone come to think that? im not arguing or anything, im just curious, did older cars act differently? and letting older cars warm for 5 be better than driving straight away?

[paulr33]

letting the engine idle for 5 minutes when cold = bad

[Munkyb0y]

if nothing else (but theres plenty else), the rich mixtures will tend to foul your plugs by idling for minutes on end while cold.

i can practically light my exhaust fumes on cold start lol. so i prefer, start, buckle up, drive off sensibly, wait till oil pressure settles to normal levels, then have fun.

Edited May 28, 2008 by Munkyb0y

[GTR_STEALTH]

did older cars act differently? and letting older cars warm for 5 be better than driving straight away?

I think in the old days especially if ur carby/choke was out of tune it was probly better to let it idle to warm up rather than have it stall in the middle of the road.

These days u just start up and drive light/normally until the temp is up....

[Ronin 09]

why would you idle for 5 mins? The motor, if under normal mild load, will warm up faster.

if you idle for 5 mins, the gearbox oil, diff oil, all bearings etc are still stone cold.

so you think after 5 mins it's good to go? the engine maybe, but everything else is still stone cold.

best to start up, drive normally after 30s and let it all come up to temperature