warming up your car

[74340charger]

I read in a HMM magazine from Jan. 2004 that you do more damage when you warm your car up to operating temp. The tech writer cited his 120,000 mile escort as not having lost any compression. I asked my father (the man who taught me to warm my car up) and he said screw that guy, he always warms his truck up and it has over 300,000 miles and still pulls like a diesel. my dad has a 96 1500 ram with the 318 and stick shift. he broke the tranny about 65,000 miles ago and is now running an 80's 4 speed. So I really want to think that my old man is right, but what is the over all opinions?

[bordin34]

How would it do damage. I think its better for everything to expand to operating specs under no load than under load.

[Silver R/T]

I let my daily driver warm up especially on cold winter days, oil has to travel through lifters and I drive at lower rpms till it warms up for a few mins.

[74340charger]

according to the "expert" when you first start your car (ones with carbs especially) it would run rich and the fuel would leak down the cylanders and contaminate the oil. I suppose I could retype the original question and answer, but it might take a few day. I really think it would be worth it to hear what you guys have to say.

[Ghoste]

As a rule, I start the car up and drive slowly for the first little while.  If it's really cold, I'll let it run for a little bit.  I guess I base it on hard it is to turn over during starting.  No science or expertise to it for me though, it's just what I do.  The daily drivers I won't own long enough for the expert way to be proven out and the 67 doesn't get enough miles on it in a year for me to live long enough to prove out either method.

[tecmopar]

Part of it is right. When I lived in the cold I would let it warm up just enough to get the choke off, otherwise you are running it a bit rich and can get cylinder wash which takes the oil away from the rings and does contaminate the oil a little. As far as the oil lubing things up, it takes about a minute unless were talking about 20* or lower temps outside, good luck.

[BB1]

The "expert" is an idiot. Have you ever driven a car with a carb dead cold, I guess he never heard of a choke. Older engines don't last as long anyways. Put in an engine oil additive if your so concerned.

[NHCharger]

The "tech" writer has an Escort, need I say more?
We always warm our cars up when it's cold. The last two, an 89 Chevy 1/2 ton work van and a 90 AWD Astro van both had 200k on them before the body rust ate them up, and both engines leaked NO oil. Actually I sold the Astro van for scrap for $250.00 and someone duct taped up all the rust holes and is still driving it.

[74340charger]

that is pretty much what I was hoping was the case. I as a rule have always warmed up my cars to operating temp. it just happens to take differant time depending how cold it is, but I guess I never let it just sit there and idle with no purpose. When I read that I shouldn't be warming my car up, unless it is to get the interior warm. that is why I thought it best to ask the people who are alot older and wiser than me.

[Nacho-RT74]

I allways warm my cars ( parents and mine ) both are carb and both are same old. If I don't do it, trust me that they will turn off alone with just gear and try to advance.

[aifilaw]

Three things to consider really that a few have touched upon that I will try to summarize..


A. One of the most important things that results in engine breakdown is achieving temperature stability of the internal components, piston top, rings, cylinder head, cylinder walls...this is especially important when using different types of metal (iron block, aluminum heads, aluminum pistons).  It takes about 30-45 seconds for an engine to achieve this temperature, putting a load on the engine before that time will severely decrease its lifespan

B. Oil must properly coat and form it's wedge surface on moving parts, it has to pump up lifters if hydrallic, and thouroughly coat all components, this will take a few seconds, to a minute depending on how long it has been since it was last started, putting a load on the engine will severely decrease it's lifespan.

C. Some vehicles run in open loop mode which is set very rich, carbs are that way too if not perfectly tuned....this leads to cylinder washdown of gasoline, which as we all know breaks down oil and will lead to severe engine wear and tear, engine load will have little or no consequence on this.


Conclusion: For a gasoline engine (not diesel) warming up an engine (in the case of ours) for 1-2 minutes before driving is all that is necessary, going beyond that is unneccessary unless you have other issues like PCV needing to warm up, or throttle body or carberator heating issues which require the carberator to be at temp to operate properly.

[Nacho-RT74]

Heeey Aifilaw!!! nice to see you again!!!

[aifilaw]

Heeey Aifilaw!!! nice to see you again!!!

good to see you too nacho.... see my other recent thread for an update..

I'm back to trolling and explaining things in such verbose unreasonable detail that others can't understand until chryco puts it into simpler terms

[Nacho-RT74]

Heeey Aifilaw!!! nice to see you again!!!

good to see you too nacho.... see my other recent thread for an update..

I'm back to trolling and explaining things in such verbose unreasonable detail that others can't understand until chryco puts it into simpler terms

not worse than me LOL

[SeattleCharger]

according to the "expert" when you first start your car (ones with carbs especially) it would run rich and the fuel would leak down the cylanders and contaminate the oil. I suppose I could retype the original question and answer, but it might take a few day. I really think it would be worth it to hear what you guys have to say.

In the BMW publication called "Roundel", in the tech talk section, this question is asked by a reader, remember reading about this last month.

Now I have always warmed up my cars and trucks a fairly long time, especially the older V8's, they don't even run worth crap when cold.  Now after reading this, on my newer imports I am not so sure, the aluminum head V6 and straight 4's.  My '87 V8 Bronco I still warm up a lot.  Warm up all my cars until the temp. gauge is at least starting to move up in the guage,

  This guy knows a lot about cars, been reading tech talk a while, keep in mind he is answering about BMW's, but some of this may be informative.

     " . . . BMW's advice on warm-up is nothing new;  in fact, this has always been the procedure.  Cars simply warm up better and faster when you drive them.      Also, just sitting with the engine running does nothing to warm up the fluids in the transmission and differential, as driving does.  And some older models run very rich in the cold-start cycle and the warm-up cycle, which means if you let them sit there and it takes longer for them to warm up, you've got all this fuel blowing around in the intake manifold, and inevitably some of it gets into the oil.  Relax, it's not the case with today's models.  In my opinion, the 'no warm-up' recommendation needs to be qualified by common sense.  Obviously, on a cold day you want to let engine idle for a little while before engaging the gears and scooting away.  Knowing what constitutes 'a little while' is where mechanical empathy comes in and the owner's manual necessarily stops.  I would say ten to twenty seconds on a normal day, maybe thirty if it's below zero degrees F, maybe a minute if it's significantly below zero.   . . .  I think the prudent course of action is to allow a reasonalble warm-up period before driving away- but that reasonable period is no more than a minute at the extreme.  I think the more important thing to bear in mind is to not rev the ingine past 3000 to 4000 rpm until the oil timperature warms up to 120 degrees or so.  But my spidey sense tells me this is one of those subjects, like politics, religion, and engine oil, where everyone has a different opinion, I've just given you mine." 

Well, driving the car will warm it up faster, duh, but that isn't the point, I just can't start up a car and not warm it up, at least let the oil and parts get warm. 
  And the trans. would get warmer if the engine is getting really warmed up. 

[aifilaw]

he is replying in the same manner that we are as well..

basically, don't put your vehicle in gear and set a load on it until between 10 and 60 seconds after starting it...EVER irregardless of what vehicle it is.

as far as engines getting up to temp, (oil, tranny fluid, and even coolant) putting a load on the engine and driving it will make that warmup process occur much much sooner (3-10x faster).

So, conclusion is....regardless of what vehicle you drive, wait about 30 seconds to a minute before putting it in gear and taking off...
if it is a carberated (see older) vehicle, or an EFI that you know does open loop untuned mode until it warms up...then let it warm up longer unti lit is driveable....putting it into gear and driving it after that 60 seconds will do less damage than letting it sit there and idle and (warm up) because it will warm up and reach operating temperature for your carb, et cetera faster...
If the vehicle is undriveable because of the choke, or EGR until it warms up...then let it sit and idle until it is.

99% of people who leave their non-diesel engines warm up for more than 1-5 minutes (depending on the outside temperature, maybe 10 minutes if it is below freezing) are stupid and in the long run either doing nothing, or potentially reducing the lifespan of their cylinder bores.

[74340charger]

okay, what i think I am getting out of this is that it depends on the engine, and if you have a proven method (like my father) don't change. this pretty much just gave every one a chance to step on either side of the fence.

[Ghoste]

Yep. 

[SeattleCharger]

This reminds me, back in maybe '90? we worked with this guy who had a brand new tpi   I-Roc Z.   This guy would start up the car completely cold, put it in gear immediately, pull out onto the street, and proceed to floor the car up to redline in first gear, and well into second, acted like he did this all the time,   I mean, that car was pretty fast, but I was like, hey man, don't you think you should warm it up a little before you just stomp on it like that and redline it?

  His reasoning, I still don't know if this is true at all, was that the air mixture is the coldest at this time so that this would be when the car has the most power.  I think he said it didn't hurt it, like he said, "nah, its fine, doesn't really matter, the car is fine".   

[LargerCharger383]

i've never heard anything about warmup doing damage...it's just idling for god's sake, if that does damage, its the car manufactures fault....what a pile of BS

[aifilaw]

This reminds me, back in maybe '90? we worked with this guy who had a brand new tpi   I-Roc Z.   This guy would start up the car completely cold, put it in gear immediately, pull out onto the street, and proceed to floor the car up to redline in first gear, and well into second, acted like he did this all the time,   I mean, that car was pretty fast, but I was like, hey man, don't you think you should warm it up a little before you just stomp on it like that and redline it?

  His reasoning, I still don't know if this is true at all, was that the air mixture is the coldest at this time so that this would be when the car has the most power.  I think he said it didn't hurt it, like he said, "nah, its fine, doesn't really matter, the car is fine".   

haha, first of all.....as long as it had oil, and waited about 10-30 seconds before he stomped on it, he would have been fine as far as engine damage...


the other important consideration is, that with engine temp, to get the most out of it requires adjusting the timing on a massive scale when the block is quite cold....if he had that, then good for him, if not, he lost more power due to timing than he gained from it being cold air

[evil1]

My wife like to let the car idle (1700 rpms) for 9-10 mins(when its cold out) until the cars up to temp (195-200)before she drives it ,I don't let  the car warn up more than a minute or two before i drive it,and at 2800 rpm it reaches 195-200 in 6 to 7 mins . It seems to take the engine the same number of revolutions to reach operating temp eather way,  So I don't think it makes a bit of difference .

[Challenger_7]

Pretty much what needs to be said, has been said, and here is a summary:

1. Few seconds idling until you know you can move the car without it duying on you. That is the first indicator.
2. Keep it in low gear and drive slowly for another 2-3 min. Watch the temp guage (if you have one in the car) and as soon as it moves, drive normally. The temp idicator is your second indicator.
3. If you have no temp indicator, just follow the proceedure above. This way you will certaqinly preserve your engine and increase its life span.

The theory behind this has been partially mentioned, i.e. to get all the parts warmed up as soon as possible, for when they are not, just imagine your engine's piston rubbing up and down at thousands of rpm's when the cylinder is still cold, therefore squeezing the piston more than when it has expanded to its normal size under its working temperature. This applies to all moving parts.
So, when moving these parts in a "tight" situation, it will certainly cause more wear and tear onto them in due course.

[SeattleCharger]

Hey, about the issue of gas going into your oil while warming up car a long time?   I was wondering, when you are driving car normally and it is all warmed up and you have been driving it, then you get into lots of long stop lights, or bumper to bumper rush hour traffic, is all this idling bad then?   When sitting at long stop lights, few in a row, etc., and you are just sitting there idling, is this fuel going into your oil happening?   does anyone turn off there car if they know they are going to be idling for more than a minute?       I wouldn't do this prob., but just curious if this is happening to car.

[Challenger_7]

No, no reason to worry about this at that point in time because the engine would have warmed up enough to avoid "rich" mixtures going into your oil.