Engine warm-up time

[MapleLeafMerc]

OK, this is a pretty feeble question, technically speaking. Yet it's something I've always wondered about.

Back in the days of carbureted engines, you had to let a car warm up for a while or they would stall on you (especially if you were driving an older/poorly tuned car). The problem was magnified in cold temperatures. Now with the wonders of fuel injection the quirks of carbs are gone, and so is that specific reason for warm-ups. BUT there's that thing I've always heard about start-up being the toughest time for engine wear, letting the oil circulate properly, etc.

So- is it possible to offer any kind of general statement about how much time should pass between the engine starting to run and when it is OK to put it in gear? This question nags me more during cold snaps like the one we're having now where it is going down to as low as -20°F. Sometimes I hear creaks and groans from the car when it's this cold that make me feel 'sorry' for it!

What about hard acceleration with a cold engine?

Would advice for the MM be applicable to most recent makes/models of cars and light trucks, and would or should the time increase as the temp drops?

[Fourth Horseman]

I've read that it's less wear-inducing to get your car going at normal road speeds and normal work load as quickly as possible. Letting the car idle in the driveway to "warm up" is said to actually be worse for the engine. I suspect that this is why our engines tend to roar upon start. It's probably programmed this way on puprose to get the engine up to operating temperature quickly.

[STLThunder]

I agree with Fourth Horseman, I was taught to start the engine, wait about 5 seconds and then drive mormally, but I usually wait until the engine has warmed up before any hard acceleration.

[greyghost]

Depending on how cold your motor is on start up let it idle 30 sec to one minute to ensure the oil is circulating then get it moving. No WOT acceleration until up to normal temp plus a few minutes to get the oil up to normal temp. Water temp will come up fairly quickly but oil temp will lag behind as it has the crank and block to warm up. This is just one persons assesment with lots of experiance

[SergntMac]

Me three agree. Start it and go. The program that revs the engine at start up will not allow much other than normal crusing until the engine reaches normal operating temp. Last winter, I timed it on zero and below zero days. 7 minutes of normal driving until the engine reached 180 degrees, and I started to get heat in the cabin. BTW, I understand the early morning groans, but letting the car warm un in the drive way won't do much for that. If you let it idle until the cabin is nice and toasty, you're actually doing more harm than good, and the MPG really sucks.

[Dr Caleb]

I can't say for the Marauder, but I let my CV idle 10 - 15 minutes in neutral if the weather is below -20C.

I find the motor hasn't come up to temp yet, but the oil is flowing and the tranny fluid has built up a little heat, making for smoother operation. Also helps clear the morning ice off the windows - less scraping. Just my $.02.

IIRC, someone here blew a motor when the just started her and went WOT, 5000rpm without sufficient oil flow. Our manual does reccomend not idleing to warm up.

[jfclancy]

:up:
Me three agree. Start it and go. The program that revs the engine at start up will not allow much other than normal crusing until the engine reaches normal operating temp. Last winter, I timed it on zero and below zero days. 7 minutes of normal driving until the engine reached 180 degrees, and I started to get heat in the cabin. BTW, I understand the early morning groans, but letting the car warm un in the drive way won't do much for that. If you let it idle until the cabin is nice and toasty, you're actually doing more harm than good, and the MPG really sucks. :up:

Well when it gets that cold I always had a block heater and in line water heater plug 'em both in for a half hour or so before initial start up. Having spent time in Montana and Alaska this seemed to work best.
However WOT before complete engine warm up WILL kill engines. Esp in extreme cold.

JMHO
Joe Clancy

[Bigdogjim]

I have always waited 3-5 minutes before driving away at any time of the year.

It is best to keep vehicle below 35 MPH till engine is warmed up.

Back in the 60's & 70's I use to change plugs often because of somethimg called a high-speed glaze forming on the plugs.
I would start up and just go!!!!!
Times change

Like I said I always let them sit for a "few" minutes.

When it is cold, if you watch the tack the RMP's will drop after a few minutes. Then go:)

[jgc61sr2002]

IMO it is disiraible to start and go. The engine will come up to operating temperature faster while your vehicle is moving. Drive moderately untill engine warms up. No WOT. :up:

[MapleLeafMerc]

Many thanks for all your replies. This shows again why I'm addicted to MM.net, because you can talk to friendly people about anything :up:

[Mark McQuaide]

My last car, a Passat V6, had a 30-valve motor. The owner's manual specifically said not to warm it up at idle because it extends the cold running time, which is when you get the most wear.

Also to consider is emissions, they want you to warm up the car quick since they release most of the emissions when cold.

Like most of the people who responded, I start it and go, and drive gently until it's warmed up.

[dwasson]

Or just do like I do and let it sit in the garage until April.

[merc406]

Warm :fire: it up to suit your own body temp, I hate freezing behind the wheel. :bounce:

[Marauderman]

[QUOTE= Also helps clear the morning ice off the windows - less scraping. Just my $.02.
[/QUOTE]

Well, I recommend what I do --I place cardboard over the windshield and held down by the wipers stopped in "mid-operation"---works everytime--no scrapping here...and as for the warm up time period--it's best summed up by saying to gently throttle till normal operation temp has been reached...which is about 7 minutes per Mac......I'd say thats about as good as your gonna get for that answer.............This place :rock:

[junehhan]

I usually start up the car, and let it idle at least 30 seconds, to a minute at most before I start going. I figure it's best to give it a little time for the oil to work it's way around before starting to move. From there, I use nothing but light throttle and keep the revs below 2500rpms until the engine has reached full operating temperature.

[schuvwj]

I usually start my MM and let her run for about 30 sec. and go but I have a heated garage so morning starts are not a problem. It was -7 deg F. this morning when I drove her to work today and my trany only got to 105 deg F. after 25 miles. The 4.30s where so cold they were making a very noticeable humming noise at 60 mph.

We need some HEAT!

[MapleLeafMerc]

Our temp gauge doesn't give any info as to the actual number of degrees. After learning that the batt/oil press gauges are non-functional, I question what the temp gauge is saying, esp w/o markings.

[MitchB]

Oil flow is reduced at low temperatures, so stay at low loads and RPMs while cold. You will also get greater fuel condensation on cold cylinder walls which will increase wear and the need for more frequent oil changes. I prefer to allow several minutes warm-up on really cold days.

Mitch

[RF Overlord]

After learning that the batt/oil press gauges are non-functional, I question what the temp gauge is saying, esp w/o markings.

Only the stock oil pressure gauge is bogus. The stock voltmeter and temperature gauge DO work; although the temp gauge is a little less useful without markings than it could be, it can still be used to indicate when the motor is sufficiently warmed-up to begin driving "normally", or to indicate a potential overheating issue if it begins to rise from its usual position...

[Marauderjack]

I watch the Oil Pressure!! ;) If it is still "pegged" at 2000 RPM's even when the water temp is "Normal".....I refrain from running it too hard!! :confused:

After about 5 minutes at "Normal" water temp the OP drops and I guess I have optimum oil circulation....Then I can HAVE AT IT!!!!! :rock:

Marauderjack :D

[Bradley G]

I always thought excessive heat (friction)was an engines enemy, exactly how much heat friction can a cold engine have?I feel once an engine has been running for even a few seconds the oil is circulating.If this is not so than how come an engine with lots of wear is noisy for a brief moment before the oil quiets it down (on cold start up) I say "drive it like you stole it":up:

[purelux]

I don't know if its true as before any of them had them they usually said it was bad, but. Since gm is now or soon will begin offering factory installed remote starts they say it actually is better on the car and enviorment. As the car will release less emmissions when running for a bit before you get in vs driving it while the engine is still in "warm up mode." As many cars seem to have more power when cold started while the air/fuel is changed from normal.

[Bradley G]

I don't know if its true as before any of them had them they usually said it was bad, but. Since gm is now or soon will begin offering factory installed remote starts they say it actually is better on the car and enviorment. As the car will release less emmissions when running for a bit before you get in vs driving it while the engine is still in "warm up mode." As many cars seem to have more power when cold started while the air/fuel is changed from normal. Mine definatly seems pepier cold:banana2:

[RF Overlord]

Mine definatly seems pepier cold:banana2:Bradley:

Most modern (last 15 years) fuel-injected cars will seem peppier when cold as the OBD system is still in open-loop mode...this is usually a richer A/F to help the car keep running during warm-up. Once the car reaches operating temp, the system goes into closed-loop mode and leans out a bit to reduce emissions. This is a simplified explanation...there's actually quite a bit more going on, but you get the drift...

[Bradley G]

Bradley:

Most modern (last 15 years) fuel-injected cars will seem peppier when cold as the OBD system is still in open-loop mode...this is usually a richer A/F to help the car keep running during warm-up. Once the car reaches operating temp, the system goes into closed-loop mode and leans out a bit to reduce emissions. This is a simplified explanation...there's actually quite a bit more going on, but you get the drift...thanks I read a little further, saw a thread using a resistor tricking the cars computer into thinking it's cold . I'm skepticle about any mods that might be intepreted as cheezie by the dealer . And any negetive long term effects this might create:o

[MitchB]

You do know that your Marauder goes into closed loop within one minute or so after start-up. OBDII (Ford anyway) brings the HEGOs online fast.

Mitch



Bradley:

Most modern (last 15 years) fuel-injected cars will seem peppier when cold as the OBD system is still in open-loop mode...this is usually a richer A/F to help the car keep running during warm-up. Once the car reaches operating temp, the system goes into closed-loop mode and leans out a bit to reduce emissions. This is a simplified explanation...there's actually quite a bit more going on, but you get the drift...

[Dan]

Will someone please clarify a bit regarding these "non working" gauges?

Thanks,

Dan

[RF Overlord]

Will someone please clarify a bit regarding these "non working" gauges?

Dan:

It's only the oil pressure gauge that's non-functional. If you notice, yours always reads 60 lbs no matter what. It's not really a "gauge", it's more of an idiot light that reads 60 lbs as long as the pressure switch on the block has about 7psi or greater. Fortunately, AutoMeter makes a replacement that DOES work and looks almost identical to the factory; P/N 4327 can be had for apprx $55 from Summit and/or Jeg's, including the proper (and required) sender.

[RF Overlord]

You do know that your Marauder goes into closed loop within one minute or so after start-up. OBDII (Ford anyway) brings the HEGOs online fast.

Mitch:

No, I didn't realise it was that quick...thanks... :up:

[Dan]

Dan:

It's only the oil pressure gauge that's non-functional. If you notice, yours always reads 60 lbs no matter what. It's not really a "gauge", it's more of an idiot light that reads 60 lbs as long as the pressure switch on the block has about 7psi or greater. Fortunately, AutoMeter makes a replacement that DOES work and looks almost identical to the factory; P/N 4327 can be had for apprx $55 from Summit and/or Jeg's, including the proper (and required) sender.

Thanks. That is very, very useful info.

Best,

Dan

[Amsoil_Dealer]

Personally I like to let the oil circulate for 30 seconds or a minute to get a little heat into it but most experts agree, the engine warms up much faster at a slow driving pace vs. sitting and idling. This is obviously much better for the trans and rear gear too.

What I want to add here though is that in my experience I have found it takes much longer to get all fluids to steady state operating temp that you might think. Those of you with functional oil and trans temp gauges can confirm that the dash gauges may look "normal" long before the car is up to temperature. I had a BMW with a functioanl oil temp gauge and it took several miles and about 15 minutes before it got to normal 180F. The point is, go a little farther before you get on it.

Don

[uwsacf]

Mine sits for at least 10 minutes warming up - even here in Florida...

How would you like it if someone kicked you out of bed the morning and rushed you out the door....???

btw - have you ever noticed - they WARM UP top fuel and funny cars!!!

and without coolant or radiators and a severe dose of nitro - they warm up real quick.

[sconut1]

I let mine run long enough for the idle to hit below 1000 rpm, and then go, which is about a minute or so. Like some of the other guys mentioned, your better off to drive the car which will warm it up faster than that letting it idle. That being said, as someone else mentioned, no wide open throttle until the car is warm.

[sconut1]

Oh no..... did I just respond to a 4 year old thread again!

[justbob]

Five year old thread

[sconut1]

Hangs head in shame......

[TAKEDOWN]

^^^ LOL... it's alright buddy, it's alright! ^^^

[SC Cheesehead]

^^^ LOL... it's alright buddy, it's alright! ^^^


Oh, I just can't resist....

OLD THREAD ALERT!!!!:D

FWIW, I usually let the Bluesmobile warm up for 1 to 2 minutes after cold start-up, and then avoid WOT until water temp gets up into normal operating range.

[04merc]

My last car, a Passat V6, had a 30-valve motor. The owner's manual specifically said not to warm it up at idle because it extends the cold running time, which is when you get the most wear.

Also to consider is emissions, they want you to warm up the car quick since they release most of the emissions when cold.

Like most of the people who responded, I start it and go, and drive gently until it's warmed up.

That makes sense seeing as on cold startup it runs rich as the engine is in open loop. allowing a quicker warmup... Somebody correct me If Im wrong..

[ctrlraven]

I let the water temp warm up to 90-100 degrees or whenever the seat starts to warm up.

[03Farmmarauder]

Dont let the car idle, the engine may be warm but the trans and rear end are as cold as ice!!!

[J D]

Old thread, but one of the first threads I remember searching for when I first joined a couple years ago. And also important for our new owners, to see as I was always raised to let it idle a car on a cold morning. Maybe sticky is in order?

[justbob]

My car doesn't move untill the temp guage is half way up and i still take it easy untill fully warmed.

[Pat]

I believe the 2K rpm start is a tach check done by the EEC program. There was some discussion on whether or not it's adjustable.

I let my MM warm up for about fifteen minutes for the first time on a cold morning 35-45 degrees. That's not for the car but for me so I can climb into a warm cabin. But during the day when the temps are above 45 I let the motor run for about 30 seconds then drive off till temps reach normal. No WOT during that time period.

[Blackened300a]

My car sits all winter, I usually just start it up to get everything circulating and then shut it down. I was actually planning on doing this today. In the summer or if I plan on driving it, I just fire it up for a few seconds and then take off. I notice in the winter,it takes a bit more throttle to get going then when it warms up.
My crown vic is start and go. As soon as the engine fires, Im in drive pulling away.

[airborne_mp84]

i usually just wait untill the rpms get below 1000