Warming up an engine

[Falcon_LS]

This is a bit of a mouthful. Personally, I go by the book and follow what is recommended by the manufacturer in the owner's manual - "commence driving as soon as possible." Every morning I always check my oil and fluids without fail, start my engine, buckle up and drive off (taking is easy on the engine until it is fully warmed up).

On the other hand I've seen some situations, best described as ludicrous. My next door neighbour and I, for instance, have same vehicle. He wakes up and starts his truck first thing in the morning to "warm up" until he hits the shower, has breakfast and is ready to leave in 20 minutes time. Others start their engine and wait in the vehicles until their engines reach operating temperature. As you can imagine, they consider it very strange and "wrong" that I turn the key and drive off. Everybody in the neighbourhood has to use the highway to commute, and an engine warms up best under load from my personal experience.

Weather conditions do not call for warming up an engine either. It's now warming up and is a rather pleasant 18 Celsius (65 Fahrenheit) in the morning. That said, it's not like we're still in the carburettor age, whereby some vehicles are required to be warmed up prior to driving.

This morning, a neighbour came up to me and commented on my "start and go" procedure. His theory was "you have to allow the oil to circulate, or engine damage will occur". We all know that oil pressure increases as the revs go up, so that is just rubbish. Another neighbour joined the conversation and commented on my recent problem with valve stem seals being "caused" by what I do. I personally do not see the connection...stem seals are a wear and tear component.

Even when I was in the UK, I always drove off. It isn't as though I redline the living daylights out of the engine right out the gate or anything like that...it barely sees over 2,000 rpm until operating temperature is reached anyway. I do not allow my engine to idle either, unless it's at a traffic light or for a very brief period. IMO, it's just wasteful...the oil ages, fuel is wasted, etc. That said, I'd be very interested to hear what you guys have to say about this one. Cheers.

 

[pcoxe]

I do about the same as you. When I get in, I crank the engine first, then fasten the seat belt, change glasses, lights, wipers, heat/ac adjustment, etc. I probably get a whole minute of warmup while getting situated. I have several minutes of low speed driving before turning onto the highway. When the weather is extremely cold, I don't push things for at least 10 minutes or so to allow things to get to operating temperature. I do the opposite when I stop. I have several minutes of low speed driving before parking, then I leave it idling while I turn off things and undo the seatbelt. I figure a little extra cool-down period can't hurt. I drove my last vehicle for 25 years like that and had over 300,000 miles on it. I don't see any problem as long as you take things easy for the first ten minutes driving.

 

[crinkles]

warming up in kuwait???? geez....

 

[JHZR2]

I think youre good... Allowing an engine to warm up via idling is a very inefficient process, and due to taking longer, youre spending more time in a regime where thermally activated adds arent working, parts that are designed to expand a bit havent expanded, and so things arent as they are designed to be.

People do a disservice driving right off in a very hard way, allowing lots of RPMs or turbo boost if applicable. However, light driving allows some real quantity of fuel to be burned, aiding in warmup.

Of course if it was sub-zero, or if you had severe knocking or an oil pressure dumy light on (or an oil pressure gauge not up to normal cold start pressure), Id probably let it idle a bit, or fast idle it a bit to get things going. But as soon as oil pressure is normal and the engine is turning, youre good for light load.

Super-heavy full loading shouldnt be allowed until about 20 miles of use or so, as it takes a good long time for oil to fully get up to temperature, and water temperature on the dash gauge is not a proper indicator in any way.

 

[RedByrd]

My car does the thing where, upon cranking, it idles pretty high for a while (15 secs to a minute, depending on the weather) and then drops to a normal idle. When that happens, I drive off easy until the temp gauge starts to climb, and then I go on like normal.

Take about three to five minutes start to finish.

 

[rg200amp]

I used to warm up for 2-5 min. Now I "warm up" for 1-2 min. I like to let the fluids get flowing. I pump the break a few times, and start off. I drive easy for 5-6 min.

So I do not let the car sit and idle, but I also do not have my foot on the gas while throwing it in Drive while turning the key.

 

[Falcon_LS]

Some interesting posts, definitely.

Originally Posted By: rg200amp
I pump the break a few times, and start off.


For whatever reason, in my owner's manual, it says to fully depress the brake pedal prior to cranking the engine in cold weather. What benefit is there to pumping the brakes or depressing the pedal prior to starting?

 

[UNC017]

Originally Posted By: Falcon_LS

This morning, a neighbour came up to me and commented on my "start and go" procedure. His theory was "you have to allow the oil to circulate, or engine damage will occur". We all know that oil pressure increases as the revs go up, so that is just rubbish. Another neighbour joined the conversation and commented on my recent problem with valve stem seals being "caused" by what I do. I personally do not see the connection...stem seals are a wear and tear component.


If the valve stem seal problem was in the Mitsubishi in your .sig, then the "cause" is the fact that its a Mitsubishi. They have a long history of eating valve stem seals, but other than that most of the engines are pretty bulletproof.

IMO you're doing the right thing, and the neighbor who "warms" his engine for half an hour is the one who's going to wreck his engine by diluting a ton of fuel into the oil, as happens when the engine is cold, unloaded, and lots of fuel/air mix blows by the cold piston rings that aren't forced firmly against the cylinder walls.

 

[Benzadmiral]

We get cheated out of any winter down here in The Swamp (and I'm not being sarcastic; I like cool to cold weather). So I'd have little warmup to do even if I did it.

Climb in the car, lock the doors, put my hat on the seat, start engine, radio, headlights, wipers if needed; seat belt; glance in the mirrors; shift into D or R, and get rolling. If the temps are below freezing, which happens once in a long while, I might let the car idle for another 30 seconds or so. For the first two miles of my normal commute I don't go over 40 mph or 1800 rpm. Then I have to let the 3.8 growl a little to handle the pace of traffic on the GNO Bridge.

In Denver's winters, with the V-8 Mercedes I had then, I often let it idle a bit while I cleaned the windows of ice and/or snow. That was so I could get some heat to defog the windows when I got back in.

I still drove gently at first, though.

 

[Falcon_LS]

Originally Posted By: 440Magnum
If the valve stem seal problem was in the Mitsubishi in your .sig, then the "cause" is the fact that its a Mitsubishi. They have a long history of eating valve stem seals, but other than that most of the engines are pretty bulletproof


The 12-valve version of the 3.0L V6 (6G72) in my truck is prone to having bad valve stem seals as it ages. The problem was corrected in the 24-valve version of this engine, and all their newer engines too. I purchased a set of the "improved" seals, which are meant to last longer, but I cannot comment on how long they will last...time will be the judge. Other than that, this engine is a dream - spares are extremely cheap and it's bulletproof as you also mentioned. I suppose you could say it's also rather straightforward to work on too, although time consuming depending on what it is you are doing. With nearly 160,000 miles on the clock, I still get an average of 8.2 km/L (20 MPG) combined.

The engine's been Auto-Rx'd and with the maintenance dose, I believe the seals should preserve their elasticity for longer, too.

 

[Quattro Pete]

Originally Posted By: Falcon_LS
My next door neighbour and I, for instance, have same vehicle. He wakes up and starts his truck first thing in the morning to "warm up" until he hits the shower, has breakfast and is ready to leave in 20 minutes time.

Warm-up issues aside, I wouldn't do that due to the risk of getting my car stolen (and insurance claim denied since keys were left in ignition), and I'm in the US. Is it that safe in Kuwait, or are you inside some military base gates?

 

[Falcon_LS]

Originally Posted By: Quattro Pete
Warm-up issues aside, I wouldn't do that due to the risk of getting my car stolen (and insurance claim denied since keys were left in ignition), and I'm in the US. Is it that safe in Kuwait, or are you inside some military base gates?


I know what you mean, although such cases are extremely uncommon. It's pretty funny, as I was just talking to an American friend of mine about theft just last week. He was rather hesitant to believe me, and left a 20 Dinar ($74 USD) note on his windsheild wiper (safely secured from flying away) for a full week. Nobody touched it, he couldn't believe it.

 

[Falcon_LS]

Thought this would be worth posting here:

Originally Posted By: The Car Bibles
The current trend is the "90% of your engine wear happens at startup" advertising ploy. This fact is absolutely true, but as it happens, it's less to to with "grinding engine parts" and more to do with combustion. When the combustion gases burn, they form acids which are highly corrosive when their vapours condense. These acids collect in the upper cylinder areas where their temperature is raised above their dew point. The acids condense and etch the cylinder walls and piston rings. In reality, this accounts for over 85% of engine wear, the other 15% being down to abrasion. So the adverts are nearly right - most of the engine wear does happen at startup, and it is because of a lack of oil, but it isn't because the oil isn't coating moving parts - it's because it's not transporting these acidic gases away. Having said that, if you start the engine and let it idle for 15 seconds or so before moving off, you can probably add another 100,000 miles to your engine's life without one bottle of additive. This warms the oil up a tad and makes sure it's in all the most vital areas before you start putting a strain on the engine. Most handbooks tell you not to let the engine warm up before driving off (they're referring to the acid corrosion mentioned above), but they mean don't let it reach working temperature. If, however, you insist on starting up and belting off down the road, think of this next time: it takes an average engine around 3 minutes of average driving for the exhaust manifold to reach 300°C. If you blast off and run around at full throttle, right from the word go, that process takes a little under a minute. Think about it - from outside air temperature to 300°C in a minute - what exactly is that doing to the metal in your manifold? Ask anyone who's ever owned an original Audi Quattro - they'll tell you exactly what happens.


Source

 

[Gary Allan]

Tell them to buy block warmers instead. They'll have their warm engines at a (probable) discount.

 

[rg200amp]

Originally Posted By: Falcon_LS
Some interesting posts, definitely.

Originally Posted By: rg200amp
I pump the break a few times, and start off.


For whatever reason, in my owner's manual, it says to fully depress the brake pedal prior to cranking the engine in cold weather. What benefit is there to pumping the brakes or depressing the pedal prior to starting?

I am not sure why they recommend it, I just do it because like I said, I like to let all the fluids flow for a few seconds before starting off.

 

[Colt45ws]

I start it up and let it idle down to under 1000RPM and then drive off. Takes about a minute..

 

[BuickGN]

I idle for at least a minute and then start my drive through the neighbohood which takes 5 minutes. It's perfect because it puts a slight load on the engine which warms it up faster but it's a very small load with low rpms.

The biggest factor is to keep the heater off and temperature setting at cold until the water is up to temp. Without the extra water circulating, it warms up over twice as fast.

 

[PandaBear]

Originally Posted By: Falcon_LS
Thought this would be worth posting here:

Originally Posted By: The Car Bibles
The current trend is the "90% of your engine wear happens at startup" advertising ploy. This fact is absolutely true, but as it happens, it's less to to with "grinding engine parts" and more to do with combustion. When the combustion gases burn, they form acids which are highly corrosive when their vapours condense. These acids collect in the upper cylinder areas where their temperature is raised above their dew point. The acids condense and etch the cylinder walls and piston rings. In reality, this accounts for over 85% of engine wear, the other 15% being down to abrasion. So the adverts are nearly right - most of the engine wear does happen at startup, and it is because of a lack of oil, but it isn't because the oil isn't coating moving parts - it's because it's not transporting these acidic gases away. Having said that, if you start the engine and let it idle for 15 seconds or so before moving off, you can probably add another 100,000 miles to your engine's life without one bottle of additive. This warms the oil up a tad and makes sure it's in all the most vital areas before you start putting a strain on the engine. Most handbooks tell you not to let the engine warm up before driving off (they're referring to the acid corrosion mentioned above), but they mean don't let it reach working temperature. If, however, you insist on starting up and belting off down the road, think of this next time: it takes an average engine around 3 minutes of average driving for the exhaust manifold to reach 300°C. If you blast off and run around at full throttle, right from the word go, that process takes a little under a minute. Think about it - from outside air temperature to 300°C in a minute - what exactly is that doing to the metal in your manifold? Ask anyone who's ever owned an original Audi Quattro - they'll tell you exactly what happens.


Source


I think that is a crock of !@#$, your car can last another 100k by simply changing all the parts that broke over that 100k, and warming up or not doesn't matter.

 

[Steve S]

Believe it.

 

[demarpaint]

Originally Posted By: Onmo'Eegusee
I start it up and let it idle down to under 1000RPM and then drive off. Takes about a minute..


That's exactly what I do. Once the rpms dip below 1000, I take off. It generally takes about 1-2 minutes for that to happen.Then I drive slowly to the highway, which is about 5+ minutes from when I started the car. Depending on which vehicle I'm driving the thermostat is usually open when I get on the highway. There is a nice long acceleration ramp so its very rare that I ever have to stomp the gas to get on. I leave the heat off until I'm into the trip about 10 minutes.