v8pwr

This doesn' happen very often. Maybe once or twice a weeks.

When I start the engine, idle goes up to about 2000rpm and it just stays there. If I shut the engine, and re-start the engine, then it usually idles fine.

This usually happens when engine is cold (when car wasn't used over night)

What could be wrong here? Please give me your advise. Thank you.

ShowGSLuVv

OK when u start the car, does it go down to about 1000rpms stays for like a second or two, then jump straight up to a couple lines before 2000rpms? if it does it like that, and only when the engine is cold, it's normal it's suppose to do that just to warm up the engine faster, leave ur car on when it goes like that for about five minutes and it should be back down.

ShOwGS

v8pwr

I know that engine idles higher duruing the start-up to warm up faster....but isn't 2000rpm a bit too high?
usually my engine idles around 1100-1200rpm on the start-up for about 3 minutes, then gradually goes back down to 800rom or so. But once in a while, rpm goes straight up to about 2000 on the start-up.

any other comments?

kreativ

It does that on both my old and new Lexus if I haven't driven it for a while.

v8pwr

So is this normal and something I need to live with?

CometVR4

Yeah I noticed it too....then it just goes back down...Does anyone notice a slight sqeaking from the belts also??
Last year...this only happen once..the car havnt been drivin for a week or so and I started it up..and the car made this loud tapping noise and stopped with that car shaking a little bit...then that stopped as well...it didnt seem normal but it only happened once so..

additude

Here it is.

GTPED

I recently bought my 95 ls400 and my cars idles around 1500 rpm or so in the morning. After the car has been driven and is warmed up, it idles smooth as can be at around 500 rpm in drive and 750rpm in park. The bad thing about the hard idle is that I don't always have time to sit til the idle lowers and I hate putting it into gear like that. I also noticed that my car has a slight squeaking of a belt and I would love to know how to fix it. Odd that I saw this topic after thinking of posting this myself. Any suggestions on the belt squaking? Seems to be commmon.

kreativ

It's recommended that you warm up your engine not through idling, but through driving slowly.
I've read this many times.

Anyone know why idling is bad for the engine?

hyperopt

Belt squeaking is due to hardening of belt rubber, a worn or stretched belt which reduces the coefficient of static friction. The ultimate fix is to replace the belt but you can apply belt dressing spray as a temporary fix.
My belt had a nasty squeak when cold idle at high RPM. I removed the belt to check other components and when I put the same belt back on, the squeak magically disappeared. My only explanation was that I put the belt on in such a way that its rotation direction was reversed.

paradox

Kreativ, I've read in a couple of owner manuals, including the one for my 98 LS that excessive idling can possibly overheat the catalytic converter(s). To be honest though, I have never subscribed to that theory..... I'm from the old school. I always let the car warm up first then drive it. Never a blocked cat either....

additude

kreativ,

I think they mean excessive idling. Especially on first startup with the choke closed and a much richer fuel mixture.

With the choke closed and with more fuel at low idle it can mean more carbon/contamination deposits in the engine and exhaust emissions that the Catalytic converter has to eat which it can't because it's not up to temp yet and it gets saturated.

Normal excessive idling wastes gasoline, you get zero mpg, plus it is harder on the whole combustion process allowing contaminents to build up because you don't get as clean of a combustion.

kreativ

Thanks for the explanation. Makes sense now.

I live on a long dead-end street so I usually let the car cruise for a couple minutes in the morning without stepping on the gas pedal. But since the RPM is lower doing this than when the car is at idle, it sounds like I should be stepping on the gas a little during the slow crawl morning warmup.