Since the guys in the Tech section couldnt really answer my question I will try over here

Basicly what counts as having your car "Warmed up"?
Oil temp? colant temp? a combnation of some things?
I have always heard 3-4 min, but would that apply when the car was running and has just been parked for half and hour? what if its 15 deg outside, is 3min enough?
Basicly I am trying to build a little light that comes on when the car is good to
drive, wont be to hard just some simple logic chips and an LED.

 

Wouldn't the light get annoying? How bout when the needle is halfway to the halfway mark?

 

I think when your thermostat opens up

 

I always wait till my temp guage needle is at normal.

 

The coolant temp guage alone is not a good indicator of engine warmth. The oil and engine internals usually take 2-3 minutes after the OEM coolant temp indicator hits the 50% stopping mark. The stock temp guage has a range of something like 160-220 degrees, where it will sit right in the middle. One reliable indication is if you have an oil pressure guage, drive on the freeway for 15-20 minutes, then when sitting at a light see what your oil pressure is. If you're waiting for the car to warm up next time you can use that pressure as an idicator as to how close your car is to full operating temp. In my experience usually 3-4 minutes AFTER the OEM coolant temp guage has hit 50% is right on full operating temps.

Good luck,

Ryan P.

 

I usually wait until the rpm's goes down to normal.

 

Just 40 seconds is good enough. But if you wanna redline it or something, just make sure when your idling, the needle is at regular idle (700 rpm +- 50) or so.

 

dang. as if waiting till the coolant temp needle is up to the halfway point isn't **** enough. waiting 3-4 minutes after that is beyond ****!!!!! i always wait until the needle begins to rise... then keep the revs below 3000 until it holds steady.

 

 

i dont let it warm up sitting there. i just drive hella slow until it warms up

 

i just make sure the needle starts rising above the "C" and drive with no boost, 5 mins later after careful driving should yeild sufficent time to open her up.

 

Me, its usually a minute- minute and a half, I creep down my driveway and I'm at normal temp. Alot of people just start 'er up and drop it into reverse, don't wait till it's stopped totally, drop it into drive and take off. Or, you could be my next door neighbor who nails his supercharger from a cold start every damn day.


[Modified by Hadji, 1:32 AM 8/7/2002]

 

I religiously let my car warm up everytime I drive it. If it is the first time I've started it in about 12 hours, I let it run until the needle for the temperature gauge is fully warm, or close to it. If I just drove it within the past few hours, sometime I will start moving if it only halfway heated up, based on the temp. needle again. The way I look at it, with all the money I have spent on my car, why not be extra careful and **** with it. The same goes for a turbo timer. How long is the right amount of time? For me, I'll leave it running sometimes for 2 minutes after just running to the store and back. Why not? Better safe then sorry is the way I see it.

 

So most of you guys just follow it by the coolant temp gauge?
Jeeezzz, and i was thinking that it would be a relationship between the coolant temp being a certin level, the oil temp, and mabey the O2 senser being warmed up....
Well I guess i dont need to build a little gaget for my car , seeing how it would be kinda stupid just to have a light go on when the guage gets half way

 

It says in my owners manual NOT to let it warm totally up at idle from a cold start. I think Honda was wrong. Most people don't do it anyway.. I cringe when I see that.

 

most new cars recommend that you drive off slowly, immediately after start up, rather than letting it warm up parked. I'm not sure if it's actually better for the car or if they are trying to avoid dumbasses warming up their cars in their garage and dying from carbon monoxide.

 

Good point. I just do it to get oil circulating and my idle goes from 1500 to 1000 or 950..

 

the technical warmup, from what i have read in manuals, is to let the cooling fan go through two cycles. then the motor is technically 'warmed up'. when the fan kicks on the first time, the coolant is up to operating temperature. when it kicks on the second time, enough time has lapsed that everything should be at proper operating tolerances. you have to remember that the pistons, being made of aluminum (along with other parts) expand and contract with temp also.

this is why running a car with no thermostat is bad for the motor. the parts were designed to run within tolerable temperature variances and when a motor is run out of its heat range, the parts will not be within proper specs. and extreme situation would be that piston hasnt expanded properly yet and can score the cylinder wall. this, like i said, is an extreme for sake of explanation, but can happen.

to be safe, just let it idle untill the fan kicks on (if you have time) and go easy on it for the first few miles; if you want your motor to last awhile.

 

wouldn't it be nice to have the m5 warm up rev limiter? the redline changes as the engine gets up to operating temperature!

 

I consider my engine warm when the oil pressure has dropped to its normal idling psi, which for me is 25 psi. I noticed that even though my water temp gauge will move into the normal range after a few minutes after start up, the oil pressure is still like 50 psi, which means the oil hasn't quite got up to operating temp.

 

when my water temp gauge(stock) reaches the middle...+ 5 mins after,.,.,.,.then shes ready to go...thats about the time the oil pressure sits at 25 psi when idling

 

I believe the reason they give is it is better for gas mileage, a cooler engine will not burn as much...or something to that affect.
I just let mine run for a minute, much longer during the cold winter days. I also dont rev the hell out of it on most occasions, and never right off the start.