Who Still Practice Warming Up of Engines Before Moving Off?

[Mini-itx]

This is my theory about why warm-up is good. At least for my case only.

 

1. Reduce piston slap. Old turbo engines (like my car) runs a great deal of clearance to accommodate the piston expansion (turbo engines run hotter, hence pistons expand more). Not a problem with new engines with tight tolerances.

 

2. Proper lubrication. When engine left overnight, oil will have flow back to oil pan resulting in hardly any oil esp. for cylinder head. New cars running roller tappets will be less of a problem but old cars are mainly using flat tappets. Oil needs time to flow thru entire block. Although oil pump is a fixed displacement pump, it also takes time for oil to flow. Its not instantaneous.

 

3. Lubrication and proper Turbo temp. Tolerance when turbo is cold vs hot is very different. And turbo is spinning at far higher speeds compared to engine and hence proper temp and lubrication is important.

 

4. Possible thermal shock. Don't know, just a guess. When you move the car, combustion temp goes up (compared to when its idle). With the cold oil and coolant, there will be a big temp difference between the cold and the hot side of the piston/cylinder walls etc. I just feel that a big temp difference is not a good thing as it causes stress and fatigue in the metal.

[Car_man]

But don't you guys feel that when engine is cold and rpm is high during initial startup, it's hard to shift from P to D.

That's is what i occur , so for me, i still practice warmup everyday or whenever engine is cold.

[Tom_kkh]

This is my theory about why warm-up is good. At least for my case only.

 

1. Reduce piston slap. Old turbo engines (like my car) runs a great deal of clearance to accommodate the piston expansion (turbo engines run hotter, hence pistons expand more). Not a problem with new engines with tight tolerances.

 

2. Proper lubrication. When engine left overnight, oil will have flow back to oil pan resulting in hardly any oil esp. for cylinder head. New cars running roller tappets will be less of a problem but old cars are mainly using flat tappets. Oil needs time to flow thru entire block. Although oil pump is a fixed displacement pump, it also takes time for oil to flow. Its not instantaneous.

 

3. Lubrication and proper Turbo temp. Tolerance when turbo is cold vs hot is very different. And turbo is spinning at far higher speeds compared to engine and hence proper temp and lubrication is important.

 

4. Possible thermal shock. Don't know, just a guess. When you move the car, combustion temp goes up (compared to when its idle). With the cold oil and coolant, there will be a big temp difference between the cold and the hot side of the piston/cylinder walls etc. I just feel that a big temp difference is not a good thing as it causes stress and fatigue in the metal.

 

 

U are right for the turbo. I used to own a manual turbo too. It refuses to "spool" up when the engine is not at the right temperature.

 

As I said how many ppl actually drag their car early in the morning in the car park?

 

after i start my engine, i will plug in my phone for charging and on the radio, its a good 1/2 to 1 minute, think its good enough as a "warm up" session for the oil to "travel" round the engines. thats my own opinion though, frankly i think no one is right or wrong, just habits.

 

Its so funny that in Europe and America, the government, car experts and car manufacturers are educating their car owners not to warm up their cars and highlighted environmental issues if everyoone warms up their car before moving off. And here most of us are doing exactly the opposite

Edited May 25, 2010 by Tom_kkh

[Shanhz]

think it's all crap about letting the oil run around etc... when u start up, the rpm is abt 1500 depending on car. i will start engine and roll along the carpark until i reach the carpark exit, which is a good 200m or about 1-2 mins.. sometimes if i am crawling and there is a fast car behind, i will just on hazard light and let him overtake me. then continue my crawling. once hit main road, drive slowly <2000rpm.

 

if you notice, all of my above habits are not much different from standing idle and waiting for rpm to drop from 1500 to 800 (i dun rev my engine while crawling). why waste the petrol? in fact, at high rpm, the car crawls quite fast and u cover quite some distance already.

 

different case for turbo of coz

Edited May 25, 2010 by Shanhz

[Mini-itx]

U are right for the turbo. I used to own a manual turbo too. It refuses to "spool" up when the engine is not at the right temperature.

 

As I said how many ppl actually drag their car early in the morning in the car park?

 

after i start my engine, i will plug in my phone for charging and on the radio, its a good 1/2 to 1 minute, think its good enough as a "warm up" session for the oil to "travel" round the engines. thats my own opinion though, frankly i think no one is right or wrong, just habits.

 

Its so funny that in Europe and America, the government, car experts and car manufacturers are educating their car owners not to warm up their cars and highlighted environmental issues if everyoone warms up their car before moving off. And here most of us are doing exactly the opposite

 

IMHO, what is stated in the manuals and by those car-experts/manufacturers may not be the best for the car. Its a case where environmental issues outweighs car lifespan. Its not a big problem for SG since many people don't keep their cars for long time.

 

But for oversea, there are far more old cars on the roads compared to SG. And these old cars do benefit from practices that could help prolong engine lifespan.

 

Its just like engine oil. Latest API:SM oil is actually bad for old cars due to lack of ZDDP. Its another case of environmental issues outweighs engine lifespan.

 

Having said that, I do not practice and recommend excessive warm up periods. As said earlier, 30s-1min is more than sufficient to warm up the car and I dont see the need to wait till meter hit 1/2 way mark before moving off.

[5936]

This is interesting.

What car is that, so many steps.

Is there safety interlock or circuit breaker, in case you miss any step.

[5936]

I am not an expert, but I think you cant get thermal shock from driving off before achieving operating temp. engine temp build up gradual and progressively. I think thermal shock need sudden and rapid change in temp. e.g. pouring cold water on hot exhaust system, or something like that.

 

Cars are designed by engineers, experts. If manual says DONT IDLE, JUST FOLLOW. Unless we are smarter than car builders.

 

Is it true that it is ILLEGAL TO IDLE ENGINE IN SG?[/color]

[Mini-itx]

I am not an expert, but I think you cant get thermal shock from driving off before achieving operating temp. engine temp build up gradual and progressively. I think thermal shock need sudden and rapid change in temp. e.g. pouring cold water on hot exhaust system, or something like that.

 

Cars are designed by engineers, experts. If manual says DONT IDLE, JUST FOLLOW. Unless we are smarter than car builders.

 

Is it true that it is ILLEGAL TO IDLE ENGINE IN SG?[/color]

 

Whats the purpose of making cars? to earn money right?

 

Car manufacturers make cars to earn money, not teach you how to make them last......

[Chilz]

I will let it run for like one minute then drive at low rev till it reaches the usual temp then go normally. Usually after the first traffic light from my mscp it would have reach the optimal temp. Not good for engine to run below it's optimal temp. Actually my prev ride clio I never warm up one juz start and drive low rpm. No problem oso.

 

yah.. no problem with your previous clio. then why u don't stick back wit ur clio? pity the 2nd owner..

[Zangetsu77]

u driving the nissan gtr right? i wouldnt be surprised if you had to do such things for such a finely tuned engineering marvel.

 

Yeah... In the same time it takes to start up, someone else might have completed one lap around Sepang...