O.k. so here are the two sides of the story:

1. It is good to warm up your engine after it has not been
started for 5 hours and up. It will allow the oil to start flowing,
RPMs to go down, and it will stress the transmission less, blah,
blah, blah... We all know the rest.

2. It is bad to warm your engine up, because of the long idle time, which can be anywhere from 2-7 minutes depending on the season of the year, and some other reasons I can't really remember.

I was always the one to support, preach and practice No. 1.
But I've been arguing with a lot of people lately on the subject, so I'm starting to doubt what I always supported.

All of you crazy Lexus fanatics should know the answer to this: which one is actually right? And why is 2 minutes of idle time bad for the engine anyways?

 

from what my dad has told me, idling for long periods of time causes damage to the timing belt, i am not sure on this, but if you idle for 15 min. for example, that is definately not good, give your car a 1-2 min. warm-up, just enough to raise the temperature line a bit.

 

does anyone else know any more on this topic, I read in the manual it says DONT allow car to idle for more than 20 minutes or somthing like that, is there some more stuff to this? thanks

ShOwGS

 

Our engines are almost indestructible. Idling for almost any amount of time won't do them any harm. All you're doing is wasting gas.

For what it's worth, I let my car 'warm up' for about 10-15 seconds! Granted it doesn't get that cold where I live (Atlanta). If it is a real cold morning (say freezing) then I'd let it warm up a minute probably.

 

Can of worms ... but nothing magical

1. (lock), Start the engine, check gauges, put on the belt, (lights), engage gear, relases parking brake and move off. Total time 10 secs or more. {This gives enough time for the oil etc to circulate}
For frigid areas, you would be using the righ oil. Give it another 30 secs or so.

2. When your car moves, the engine (+ trans) warms up quicker. {Optimum operating conditions are reached quicker, emission etc}. Trans ecu will assist. By moving you are helping the car warm-up quicker. Radiator cooling is blocked off by the thermostat.

3. When you reach optimum operating conditions you can stress the engine + trans


Idle for long time (20 mins +) is not reccomended as there may not be adequate cooling (over heating) due to NOT enough air passing thru the radiator. {shops use large fans}

Reccomeded service intervals are based on Miles(km) traveled. Extended idlling throws that number off. eg timing belt life realistically is based on rotations, but it is replaced based on odometer reading.

Salim

 

Salim - I agree

 

salimshah: Well said.
I used to wonder why the manual for our other car(not Lexus) stated to drive the car 'right away' after starting. I had always thought it was best to let a car 'warm up' by idle.

It still sounds a bit odd.......but I guess I understand now.

 

i agree that idleing isn't going to hurt it.

hell, sometimes i just sit in mine while it's running and make vroom vroom and screeching noises.

see, this way, i get the feel of driving my care w/o adding the miles.
plus, i can drink while i do it!

 

GUYS,

i just had my throttle body cleaned and i notice that my RPM is higher than it used to be when i first start my car in the morning. it looks like it's around 1400 RPM when it starts out. what do you guys have?

 

Salimshah, thanks a lot for the practical info.
You answered my question and some.
Keep it Lexus, duke. Thanks once again.

As far as my RPM, when my engine fires up,
it's around 1600. Hope that helps GSquicksilver.

Regards.

 

whew! great to know that my engine warmup rpm is around there. now i know my engine is running normally. thanks rover!

 

It's all good, GSquick.
Anything for a fellow Lexus fanatic.
Keep it Lexus.

 

...the manual says to let the car warm up for 10 seconds prior to shifting outta park.

otoh, you shouldn't go beating on the engine / tranny before you're at normal operating temp (reference the fact that you can't M-shift down to second gear before you're above a certain temp).

personally, i use 'snow' mode for the first couple of miles of my (stop-and-go) commute in the am-- coupled with gentle acceleration, keeps revs under about 2500 or so. it's thoroughly nonscientific, but makes me feel better.

btw, idling to the point of engine damage would require overheating, wouldn't it? and having just driven an LS430 up and down I5 in OC in stop-and-go traffic at 115 degrees with the AC on full-blast without the temp bar moving one bit, i'd say our cars have rather good cooling systems... as opposed to the jeep cherokee i used to drive.

FP