cold revving

[TBITB]

every morning, the woman a few houses down gets in her '00-02 maxima and revs the engine for about five minutes. she revs slow, fast, and sustains a high rpm for a significant time. it's kinda annoying

i was told that doing stuff like that, especially in the winter time, is like waking up in below freezing temps and running outside naked . and it can damage the engine. the oil isn't properly warmed to lubricate the moving parts for hard revving right? i am cool with this person so i want to have the facts before i tell her shes gonna blow up her engine!

[hotrice]

well i have a couple buddies who have xb's that have a special guage on their dash that tells them the ideal temp before driving off but for some reason the tc doesn't in my personal experience i have always let the car run for a couple minutes so that the oil can run through the engine.

[TBITB]

thats what i do too especially in the winter time.

[Soulbane]

That is extremely bad for the car.

Excessive idle revving isn't good for your car as is, and revving to mid and high rpms before your carm warms is just asking for future troubles.

It's temperature shock, and it applies to everything. Ever put ice cubes into warmer temperature liquids? The cubes break or shatter. If substances are forced to change temperatures at a overly rapid rate, the molecular structure's strength and integrity of that substance is compromised. Just like you don't dunk a searing hot skillet into a tub of cold water to clean it. This isn't any "autmotive myth" or what not, it's just straight science.

Let her do what she wants to do. I just start the car, let it sit for about 4-5minutes and allow the car to reach it's standard idle RPM.

It's not gonna blow up her/his engine, but if kept up for extended periods of time, it will have effects on the longevity of the vehicle.

[08supawhite]

Revving your engine when you first start it up and it's not warm yet will cause premature wear on internal engine parts. This is because after the car has sat overnight or for a substantial amount of time, the oil has had time to drain out of the top of the engine and back down into the oil pan. It takes a minute or two of the engine running to get the oil pumped back up to the top of the engine to start lubricating the moving parts properly. Also the metal parts haven't had enough time to expand properly from temperature change to their operating tolerances.

Also, if you are holding a steady idle (1000-1600 RPM's) it will not hurt your engine in fact, some companies program their ECU's upon startup, to hold around a 1300 RPM level to let the engine properly warm up. Anything in extreme excess of this threshold is destructive to your engine.

As a rule of thumb, until the engine starts to sound/feel normal, I do not drive it.

[n0speedlimit]

reving your rpm's when the car is firts warming up specially in the winter is very hard on the motor over time it will damage it!!

[TBITB]

cool i thought those were the answers to this. i feel bad for that engine. but whatever. i let mine get down to about 1k as well. remote start helps big time as well!

[hotrice]

yep best thin i do is start it and as soon as i see the temp move just a remote bit i head on to where i'm going.

[navylife59]

All this holds true even during the Summer months. If you have an auto, the fluid needs to warm up to a specific temp to operate/lubricate the torque convertor, solenoids, and clutch packs correctly. This holds true to any hydraulic system closed or open loop. Even on a 100 degree day, you should allow your motor a minute to stabilize from a cold start.

[ghostrider]

I know I am new here, and I am about to reply to a somewhat old post; please hear me out.

When I first bought my '09 Scion tC I read its manual in entirety. I came across this odd entry, on page 180 (Section 3b -- Starting the engine) that states that the, "engine should be warmed up by driving not in idle. For warming up drive with smoothly turning engine until engine coolant temperature is within normal operating range."

Everyone I know "warms" their car up before they drive it by letting it idle. I can't speak for other cars, as I have not read their manual, but the owner's manual for a stock '09 tC clearly states that the preferred method to warm its engine is to smoothly and easily drive it!

Just though you all would like to know that...

-ghostrider

P. S. I posted this here because I just recently decided to reinvestage this point so I could squelch this debate I've been having amongst my friends, about warming up my car, once and for all.

P. P. S. Cold steering wheel == lose.

[navylife59]

Maybe I can shed a little light. Not LED or HID mind you, just good old incandescent although lasers would be freaking sweet.... oh, sorry. Off tangent here.

The 2AZ-FE is a very tight tolerance motor. Tight tolerance motors do not have the need to warmup to operating temperature to prevent damage as is older, loose tolerance motors, ie. Ford, GM, Dodge and for some reason, my new Tundra! The 2AZ-FE uses 20W oil that has molecules more tightly bound that reduces heat expansion.

The other, more prominent, reason has everything to do with emissions (Thanks Cali!). A cold engine at idle produces more emissions at idle because of the rich condition. At higher engine speeds, rich conditions are not needed to keep the combustion going even on cold start engines. This equates to less emissions. Just a way to keep Al Gore off your back.

[ghostrider]

Very informative reply. Thank you.

So, if I understood you correctly then it would be fair to say that: warming up the 2AZ-FE before driving is a completely safe and acceptable thing to do? And that the owner's manual advocates immediately driving the car while it's cold, not to prolong engine life, but instead to be more enviornmentally friendly?

[Redneck4csa]

Very informative reply. Thank you.

So, if I understood you correctly then it would be fair to say that: warming up the 2AZ-FE before driving is a completely safe and acceptable thing to do? And that the owner's manual advocates immediately driving the car while it's cold, not to prolong engine life, but instead to be more enviornmentally friendly?

Correct. I always let mine warm up before I drive it off. It has to at least get to the first bar before I will pull out.

[ghostrider]

Well, the old lady will be happy to hear about this, no more driving around in a mobile freezer for the first 10 minutes. I'm surprised the owner's manual would deny the reader the opportunity to let their car warm up if they'd like. The wording places a negative connotation on doing so.

All in all, refreshing news, especially when it's so cold that I had to let the car warm up to defrost the windows.

[Redneck4csa]

Well, the old lady will be happy to hear about this, no more driving around in a mobile freezer for the first 10 minutes. I'm surprised the owner's manual would deny the reader the opportunity to let their car warm up if they'd like. The wording places a negative connotation on doing so.

All in all, refreshing news, especially when it's so cold that I had to let the car warm up to defrost the windows.

What it all boils down to is what YOU want to do with YOUR car. All they do is make and sell you the car. They can't tell you how to drive it or take care of it.

[ghostrider]

What it all boils down to is what YOU want to do with YOUR car. All they do is make and sell you the car. They can't tell you how to drive it or take care of it.

I agree completely but if they were to claim that the engine life would be decreased by letting it warm up before driving then I would have no qualms with driving it immediately (just as I have no qualms with changing the oil every 5Kmi rather than 15Kmi, because doing otherwise than directed could be problematic unless known otherwise). I hope my point has not gotten lost in translation.

-ghostrider

P.S. I only made the initial contribution in hopes of helping fellow tCers.

[Redneck4csa]

I agree completely but if they were to claim that the engine life would be decreased by letting it warm up before driving then I would have no qualms with driving it immediately (just as I have no qualms with changing the oil every 5Kmi rather than 15Kmi, because doing otherwise than directed could be problematic unless known otherwise). I hope my point has not gotten lost in translation.

-ghostrider

P.S. I only made the initial contribution in hopes of helping fellow tCers.

We understand your point completely. Kind of sounds like you're being defensive. Trust me, no one is flaming you. Especially me. All I'm saying is that any car I've ever owned (and I've owned alot for my age), I've always let it warm up before I drive it off. Screw the manual on this one lol.

[ghostrider]

I think I am being defensive too but not with you -- instead with myself. I froze my **** off driving that thing from a cold start and I want to think it was for a worthy cause!



Not to mention: sometimes I had to go a little faster than I would have liked with a cold engine when morning traffic was heavy. And I hate having to shift gears before the gear oil is warm... although I am very consciencious about waiting for the revs to fall near next gear speed, so although the synchro work was more pronounced, it was still nominal.

[Redneck4csa]

I think I am being defensive too but not with you -- instead with myself. I froze my **** off driving that thing from a cold start and I want to think it was for a worthy cause!



Not to mention: sometimes I had to go a little faster than I would have liked with a cold engine when morning traffic was heavy. And I hate having to shift gears before the gear oil is warm... although I am very consciencious about waiting for the revs to fall near next gear speed, so although the synchro work was more pronounced, it was still nominal.

That's why I wait until I have heat . Well, what I do is let it warm up until at least the first bar and then I go out. I also don't shift over 2500rpm until it is at full operating temperature.

[navylife59]

Run full synthetic gear and crankcase oil. Loose the worries. You can read this little bit about oil viscosity if you want to know more.

http://www.autoeducation.com/autoshop101/oil-change.htm