Taking It Easy on a Cold Engine - Why?

[LeakySeals]

For all the reasons stated I let the engine tell me when its ready. When the warmup high idle starts to normalize, time to go. Thats generally 1-3 minutes depending on temps.

 

[motor_oil_madman]

Look up cold seizure. Happens with outboard motors.

 

[North to Alaska]

How long does it take for your engine to warm up? Just curious. I had a thermostat that opened too early. Around 160 deg it would start to open. Coolant would not go above 180 deg. So when my engine (2011 equinox) received an overhaul (new rings and pistons courtesy of GM) they had to drain coolant. So I had them replace the thermostat while they were at it. Now coolant acheived 195ish. Don't know what the oil temp was before since i didn't realize I could monitor that till afterward. Funny how the service rep told me there was no problem since there was no cel. I asked him then why he was rebuilding my engine since there was no cel for that either...

 

[IndyIan]

Originally Posted By: motor_oil_madman

Look up cold seizure. Happens with outboard motors.

My parent live 200m from a fairly busy highway and they've never regularly plugged in or warmed up an engine in the nearly 50 years they've lived there and none have had an issue with this. My Dad had an old Datsun that would be pretty much matted 1 minute after a cold start, for a couple miles until the car got to 60 and the oil warmed up... I'm sure its not ideal to run a cold engine at 1/2-3/4 throttle to 60mph within a minute of a -10C start, but for them it never seemed to be a problem.

 

[69GTX]

Shannow's thread on warmup seemed to show that driving at 1800-2200 rpm once you're actually driving is somewhat optimum for both a rapid and proper warmup....if you have the roads to do it. Overdrive at 1400 rpm at the same speed not as efficient. I now shoot for around 2,000 rpm for the first few miles (around 40 mph).

 

[Danno]

I have a 6% grade with passing lane about 1/4 mile from my office, with a 55 mph speed limit. I tend to take it slow and easy when taking the grade, keep rpms under 2500, until engine warms up. On a very cold day (-10F), I did my usual routine, was merging with a OPP cruiser, (state trooper for US folks) and he pulled me over - thought I was drinking and being extra careful as there was a cop around. Didn't really understand my explanation of taking it easy on a cold engine.

 

[Camprunner]

Originally Posted By: ARCOgraphite

Had to do this with my Toyota MR2 in the mid 80's. Route 495N Highway was about mile from my apartment in Shawsheen village in Andover, Ma. That engine was toast in a year. Burning oil and low compression. Piston to wall clearance isn't settled in, oil flow through rings and splash isn't that good, valve clearance is high on SUB DOHC and some oil additives such as antiwear, anti scuff are not fully activated. Does this make a difference? IDK. My Toyota may have been a fluke - but that was the only car that got flogged cold and it couldnt take it.

Route 495 "The Zoo!" Just don't tick someone off on 495 or they will hunt you down! ...lol

 

[SevenBizzos]

"Warming up" a car when it's near freezing is completely different than the same process at -15F.

 

[Nick1994]

I visited my dad once up North in the Camry and it was near freezing outside. He lived by a highway and I went to merge on the highway and it just wouldn’t do it. It has no power at all when cold, didn’t want to rev up and shifts at like 3,500 RPMs when cold. It’s a Toyota thing. I had to immediately pull over on the side of the highway and let it warm up, I would have been rear ended. I usually take it a little easy when cold, but our cold is a lot different than other people’s cold.

 

[Tman220]

Originally Posted By: Iowegian

How long does it take for your engine to warm up? Just curious. Funny how the service rep told me there was no problem since there was no cel. I asked him then why he was rebuilding my engine since there was no cel for that either...

I suppose that was the 2.4 liter that was rebuilt due to oil consumption? This was a known and very common issue with the 2.4. This was due to a coating on the top ring wearing off because it wasn't robust enough. Low water temp could have prolonged warmup time, which could have aggravated it, but it certainly wasn't the root cause...

 

[zorobabel]

Originally Posted By: 5AcresAndAFool

I haven't figured out if it's a catalytic converter temperature or an engine coolant temperature parameter that has to be met and not to allowing the sooner shifting into high gear on the Toyotas but it's kind of frustrating.

It is determined by ATF temperature.

 

[6starprez]

I live in south and my car is garaged so of course the colder it is, the longer it takes for the blue light to turn off. In my Impreza, I go when the light shuts off and the idle go down simultaneously at 120 degrees. I wait because it would bother me psychologically to put my car in gear when it's revved up around 2,000 rpm.

 

[Shannow]

Originally Posted By: d00df00d

On a cold start: 1. Oil is too thick 2. Clearances are too small 3. Fuel mixture is too rich If you use too much throttle or rev it too high, you'll cause excess wear. You'll also load up your catalytic converter faster (more combustion byproducts) and may cause greater fuel dilution in your oil. A turbo would worsen the excess wear if you're too eager to drive on-boost, and it's another part that'll suffer more with that too-thick oil. Best thing to do on a cold start: let it idle for up to 30 seconds as StevieC suggests, and then pull away gently with the interior heater OFF. Drive mildly until it's up to temp. Then you can turn the heater on and drive as you want.

1. No it's not...as suggested, it has higher viscosity, keeping parts mechanically separated. There's a reason that the Sequence IVA uses 65C as the test point. The oil is thinning, and the additives aren't functioning yet. Bobbydavro advises that he's done the test at colder temperatures (thicker oil) and hotter temperatures (thinner oil, better additive activation) and both cases are better wear wise (camshaft) than the test temperature. 2. No they aren't...an Aluminium piston in an iron bore will have greater clearance cold than hot. A steel crank in an iron block, they will both shrink expand the same for a given temperature. Crank will heat faster than the block, but the delta in clearances is tiny. 3. Yes, agree, but the doomsday scenarios that follow aren't realistic. VP, it's best not to thrash an engine until everything is happily at temperature, and you are in a range that the additives are fully functional...but a bit of a squirt to manage traffic isn't that much of a biggie over the course of your ownership.

 

[StevieC]

Oil doesn't pump as well when it's colder and when it was parked all the oil falls away from most of the parts so this is why it's not a good thing.

 

[SwampDweller]

Living down here on the gulf coast.....I have to ask, WARMUP ???????? Start car and drive normally, done deal.

 

[Shannow]

Originally Posted By: StevieC

Oil doesn't pump as well when it's colder and when it was parked all the oil falls away from most of the parts so this is why it's not a good thing.

which colder ? The galleries are full, and the oil is everywhere it needs to be by the time that you've got your seatbelt on in anything above freezing. As to oil draining off stuff, I've pulled apart engines that have been sitting for YEARS, and end up covered in the stuff...there's stuff held in every nook and cranny through capillary action. The wear that occurs is during "warmup", not "cold start" and dry engine.

 

[d00df00d]

Originally Posted By: Shannow

1. No it's not...as suggested, it has higher viscosity, keeping parts mechanically separated. There's a reason that the Sequence IVA uses 65C as the test point. The oil is thinning, and the additives aren't functioning yet. Bobbydavro advises that he's done the test at colder temperatures (thicker oil) and hotter temperatures (thinner oil, better additive activation) and both cases are better wear wise (camshaft) than the test temperature. 2. No they aren't...an Aluminium piston in an iron bore will have greater clearance cold than hot. A steel crank in an iron block, they will both shrink expand the same for a given temperature. Crank will heat faster than the block, but the delta in clearances is tiny.

Thanks for the corrections.

Originally Posted By: Shannow

3. Yes, agree, but the doomsday scenarios that follow aren't realistic.

I more meant to describe effects that could accumulate over time. Isn't that pretty much necessarily true, the only question being one of degree?

 

[Alfred_B]

Originally Posted By: StevieC

This is why you wait and should be gentle when the engine is cold. (Depending how cold) https://www.youtube.com/watch?v=MVn5OzuHtjg

Interesting to see how fuel dilution in the used conventional oil made it more viscous.

 

[Shannow]

Originally Posted By: Alfred_B

Originally Posted By: StevieC

This is why you wait and should be gentle when the engine is cold. (Depending how cold) https://www.youtube.com/watch?v=MVn5OzuHtjg

Interesting to see how fuel dilution in the used conventional oil made it more viscous.

it's not fuel dilution that makes it thicker, it's usually the VIIs and PPDs playing up. Also, they aren't doing apples to apples, and they haven't told us the grades. If they are using (say 10W at -30C), then the synthetic simply has a better pour point, nothing to do with the "W" rating. If they are using 5W, then the dino is not in spec. It's a sideshow stunt. And besides, I don't know of any engine components that have the oil "poured" on them

 

[StevieC]

Here... 5:30 in https://www.youtube.com/watch?v=tYkg0oDUXs8