To Warm up or Not to Warm Up?

[Offroader Member Find all posts View Profile Close Offroader]

It seems that warming up an engine on a cold morning has gone out of vogue and is even discouraged as unnecessary with fuel injected vehicles. Whilst driving off slowly seems to be the recommended procedure to reduce emissions and hasten the warming process, I cannot help but wonder if this practice in the long run will increase engine wear by loading a cold engine. I personally like to see the water in the mid 40's on the Scanguage II before I drive off. This seems to only take a minute or so. I would be interested to hear whether other V6 owners idle to warm or simply drive off.

[mkh Senior Member Find all posts View Profile Close mkh]

Re: To Warm up or Not to Warm Up?

In the morning I start her up, then while I've put the seat belt on and fluffed around with the stereo the engine speed has usually dropped from the fast idle so then I drive off.
I just don't work it too hard for the first few kms. A friend of mine just gets in his car and within 2 seconds of starting it is already halfway down the street. I just can't bring myself to do that. I think it's called having "mechanical sympathy".

[Davros Advanced Member Find all posts View Profile Close Davros]

Re: To Warm up or Not to Warm Up?

I don't have a V6 but in my older diesels I have always warmed them up for a while before driving, and then kept revs down before temp has reached normal operating range.
In the 120, i wait for the idle up to finish before driving off and then keep revs down as above. Seems like common sense to me.

[Offroader Member Find all posts View Profile Close Offroader]

Re: To Warm up or Not to Warm Up?

I've heard that pre-lube oil pumps have been successfully used in reducing engine wear by as much as 40% on start-up, but these units seem to be more prevalent on engines used for industrial applications. Perhaps a cheaper option would be the famed Castrol Magnatec which "sticks' to your engine! Just how oil can possess the physical properties of magnetism is another question entirely :?

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

Re: To Warm up or Not to Warm Up?

Hi,

I am not a big fan of warming up the engine by idling, whilst i understand the reasons why, you still take of with cold tyres, gearbox, brakes, diff and so on. i think a gentle take off and keep the revs to a minimum for the first few minutes and let it all warm up together. We used this method on our Camry and never had to put a drop of oil in between services and sold that a 200 000 kms.

Cheers Andrew

[waltec Senior Member Find all posts View Profile Close waltec]

Re: To Warm up or Not to Warm Up?

The problem with modern engines is the number of different metal used in their construction, and each one expands at a different rate when heating up. They are designed to fit together when hot, not cold. This can cause so much stress the F1 teams actually have a warm up program (laptop takes control of the ECU and has a predetermined map that is used to warm the engine so as to balance the stress from being cold and reving too quick, they actually lift revs quite high to acheive this, but no load. Although we're not driving FI cars, they are after the same thing reducing stress to maximise life..

Matt

[bitdist Senior Member Find all posts View Profile Close bitdist]

Re: To Warm up or Not to Warm Up?

Dr Karls take on it all......


I've had a lot of fun teaching the Junior Members of my Family how to drive the Family Chariot. But along the way, I realised that something I had done for a long time was actually wrong. Previously, I tried to be "kind" to my car's engine by giving it a nice long idle before I pulled away from the kerb. But when I went looking, I found that long idle was actually harming the engine, and the environment, and my wallet.
The powertrain of a car is the mechanical stuff that makes it go. The power starts at the engine, goes through the gearbox and finishes at the driving wheels. Les Ryder, the chief powertrain engineer from Ford, USA, said in the January 2007 issue of Popular Mechanics, "Engines run best at their design temperature". In other words, Mr. Ryder is telling us that engines run most cleanly and efficiently somewhere between 85°C and 95°C. Idling is not the best or quickest way to warm up your engine. Gentle driving is.
The Canadian Office of Energy Efficiency agrees that the best way to warm up your engine is to drive it. Even if the outside temperature is -20°C, they recommend that you idle the engine for only 15-30 seconds before you pull out onto the road. You need even less idling time at the temperatures we usually experience in Australia.
Idling an engine is bad in so many ways. The fuel is not completely burnt, so it condenses in drops on the cylinder walls. This leads to both extra wear of the cylinder walls (because the fuel washes the lubricating oil off the walls), and unburnt fuel flowing down the walls and contaminating the oil in the sump. Idling also drops the temperature of the spark plugs, leading to dirty plugs, which can worsen your fuel consumption by some 5%.
You might have noticed a vapour coming out of the exhaust of some cars in the early morning. That vapour is not the oil vapour of a worn engine, but the normal water vapour from a cold engine. So the longer you idle the engine, the longer it will take to warm up, and so more water droplets will be deposited inside your exhaust system – making it rust sooner.
A long time of idling means that the engine will produce a lot more unwanted pollutants. For example, modern cars have catalytic converters. When they get to their normal operating temperature (400-800°C, which is a lot hotter than the engine), they convert nasty pollutants into much less nasty chemicals. And you guessed it, the quickest way for catalytic converters to get to their normal operating temperature is by driving, not idling. The longer the time that you idle your engine, the longer that your catalytic converter is too cold to do its job.
Canada has started a national campaign to reduce unnecessary idling of engines. There are similar regional campaigns in Japan and the UK, and in the USA, 13 states have now passed laws regulating idling of engines. The ski resort town of Aspen, in Colorado, has passed laws making it illegal for car engines to idle for more than 5 minutes.
People are now talking about the benefits of switching off your engine in traffic, if you are going to be stopped for more than 10 seconds. But this is exactly opposite to the Remote Start function, available in some US cars, which lets you start the engine from some 60 metres away. The advantage is that you walk out of your house into a nice warm car. The disadvantage is that in 10 minutes of idling, you burn about half-a-litre of fuel.
The Canadian Office of Energy Efficiency crunched the numbers for the hypothetical situation of each Canadian driver idling their engine for 5 minutes fewer each day. Over a year, that reduced idling would save Canadian drivers C$646 million, and stop 1.6 million tonnes of greenhouse gases from escaping into the atmosphere.
When you idle a car, you get zero miles per gallon, lots of pollution, and a hole in your wallet.

[humphrey Junior Member Find all posts View Profile Close humphrey]

Re: To Warm up or Not to Warm Up?

It's not the water temp you want up. It's the oil you want up to temperature. Idle away all you like, sure your heater will be toasty when you get in but in reality the engine itself is still cold. The best way to get the oil temp up is the rise and fall of engine revs. Idling does nothing exept move thick cold oil around your engine. When engine revs rise and fall, the oil moves slower/faster/slower/faster. In the process it heats up, thins and performs as it should. As mentioned by waltec, race teams sit in the garage reving engines via ECU and without load. I've seen the MotoGP bikes up close, they sit there cracking the trottle on and off to near redline for 5 minutes. With passenger vehicles the quickest way to get the engine up to temp is to drive it. Just dont flog it when it's cold as it takes a good 10 kays of driving to get the oil up to working temp. Thats one of the reasons short trips all the time can be harmfull to engines, the oil never gets hot enough to work properly, which in turn accelerates engine wear.

My 2 cents worth.

[StormyKnight Advanced Member Find all posts View Profile Close StormyKnight]

Re: To Warm up or Not to Warm Up?

Where I live I drive about 400m to the highway & I have a Diesel. If you start it & drive even after opening one gate it is still very sluggish & it is definitely not happy for a few kilometers down the road. The ECU controls the engine power till its warmed up. I had heard that the Holden Jackaroos of an older generation where renowned for this issue & it was very pronounced.

The main reason I like to idle for a while is to avoid the issue when i try to reach 100km/h in traffic. If I'm sitting in the car I will fast idle the car to assist.

[chester Advanced Member Find all posts View Profile Close chester]

Re: To Warm up or Not to Warm Up?

start it drive it out the drive way then down the flat road by the time i hit the first hill it is warmed up. I will say but when i have the camper on and have packed up and the car is cold i will start it then do my final walk around and rubbish disposal before driving so it has a bit of time to warm up

[bilo33prado Senior Member Find all posts View Profile Close bilo33prado]

Re: To Warm up or Not to Warm Up?

It's not the water temp you want up. It's the oil you want up to temperature. Idle away all you like, sure your heater will be toasty when you get in but in reality the engine itself is still cold. The best way to get the oil temp up is the rise and fall of engine revs. Idling does nothing exept move thick cold oil around your engine. When engine revs rise and fall, the oil moves slower/faster/slower/faster. In the process it heats up, thins and performs as it should. As mentioned by waltec, race teams sit in the garage reving engines via ECU and without load. I've seen the MotoGP bikes up close, they sit there cracking the trottle on and off to near redline for 5 minutes. With passenger vehicles the quickest way to get the engine up to temp is to drive it. Just dont flog it when it's cold as it takes a good 10 kays of driving to get the oil up to working temp. Thats one of the reasons short trips all the time can be harmfull to engines, the oil never gets hot enough to work properly, which in turn accelerates engine wear.

My 2 cents worth.

Spot on there B Bear Temp gauge in car is only water temp. Oil temp takes longer to get to correct operating temp. That's why a Taxi in a big city that operates 24/7 will get 800 + km on the clock no worries as it's oil is running at best temp range. VERY HIGH percentage of a engines wear is when oil is cold. IMO
Cheers Geoff

[Hughda Lurker Find all posts View Profile Close Hughda]

It is slightly OT, but my D4D cools down quite quickly if I leave it idling in cold weather. It may be at 85 when I stop but within 5 minutes it is down to 75 or even lower. Idle-up doesn't kick in till it is below 70, but even then it just holds that temperature. Is this normal?

[discoveraus Member Find all posts View Profile Close discoveraus]

Idleing a diesel engine, Hot or Cold, is not good for the mains or big end bearings as the firing point is just about top dead centre and this hits the pistons, big end bearings and main bearings when they are all in a straight line. All diesel engines should be idled at about 1200 rpm if you are going to leave them running.

It is more important to get the engine oil pumped everywhere inside the engine before driving than warming the water jacket up. The oil light goes out in seconds but the thick oil is still making its way upto the top of the engine well after the light goes out. Modern oils are very thin when warm and need some short time to warm up, thin out and get into every nook and cranny inside the engine so the engine is properly lubricated.

Fast idle for about 30 seconds is enough, start the engine, put your bits and pieces ( ie hand bag or briefcase) down and then fasten your seat belt, 30 seconds gone.

regards

Ross

[Hpycmpr Junior Member Find all posts View Profile Close Hpycmpr]

Good read here. I have always warmed up, under the impression that while it might not achieve much, it certainly wouldn't do any harm. Clearly the comments he suggest otherwise. Guess I'll have to rethink!

[butane8 Avid PP Poster! Find all posts View Profile Close butane8]

120 v6 here.. i warm up slightly . and ease down the street .. once the water temp at normal on the guage .. i'm into her..

i dont drive for fuel ecconomy... i drive the v6 for performance.. and love it .. especially with the 6 spd manual box...