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WARMING THE ENGINE BEFORE DRIVING?
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My neighbour reckons I'm DOING IT WRONG by driving off when I've just started my car. I told him that I've done this almost every day for the past 4 years and my car's OK.

He then goes on to give me a in depth explanation about how cold oil doesn't circulate and a car's engine can be damaged by not warming it up and can considerably shorten it's life.

I told him I think he might be DIW. As when I drive off I keep the revs well under 3000 for a good 5 miles even after the fluids have warmed up. He says that will damage it.

So am I DIW, or is he?

If you've cleaned the MAF you're fine.

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DeskJockey
---
Now fueled by heavy oil...

Best way to warm it up is to gently drive it, not to leave it sitting there idling.

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Impreza WRX STi Spec-C V-Limited Toshi Arai Edition/ GTR/ Panda 100HP Pandamonium/ 316d

YAC

he is DIW

Most manufacturers recommend driving off ASAP (but obviously limiting revs and throttle until coolant and oil have come up to temp (the latter lagging behind a good 10mins / 10 miles).

Starting from cold and idling for ages is believed to be a good way to suffer bore wash (rich mix at cold start means unburnt fuel can slip past piston rings that aren't being forced to seal well (due to cold and lack of load), washing the oil away when you need it most).

Also - most modern diesels are so thermally efficient that they won't warm up when just idling.

Updated December 3, 2012 at 11:18 AM

Certainly one has to wait for the oil to warm up before high revving the engine...
But I'm not sure leaving the engine at idle for a relatively short time will actually help, since when idling it will need more time to warm up (I never checked on a temp gauge how long it would actually take to reach the recommended temp from cold when only idling) - and if it's not only idling there's no difference between moving or not.

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Pilouil
Citroen C3 1.4 HDI 69.0424 bhp

You both are. You need to rev the engine like F1 cars do in the pits.

There's a man I pass every morning whilst walking my eldest to School & every day he's revving the tits off his Zafira diesel before zooming off & it sounds awful!

One day his conrod will make a bid for freedom & I shall be there to witness it.

AFIAK, the correct procedure for a cold engine is to start it, put your belt on etc, then drive off normally.

It won't hurt if you leave it idling for a few minutes whilst you scrape the ice off & you should never start it, set the heating to max, lock the door with the spare key & go back into the warm & finish your breakfast.

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Cheers,

Gwaredd

steelesigns.co.uk

Surely the whole idea of Ford's quick heated windscreen is so that you can set off ASAP :lol:.

And what does he drive?

Warming die sels makes sense before clattering off down the street.

Mark BT52 said...

Best way to warm it up is to gently drive it, not to leave it sitting there idling.

Thread closed.

Gwaredd said...

you should never start it, set the heating to max, lock the door with the spare key & go back into the warm & finish your breakfast.

You'd have to be mad to do that, because this implies that your breakfast was ready before going out to sort out the car, and surely by the time you got back inside the milk would have made your cornflakes all soggy, or the cat would have eaten it.

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Impreza WRX STi Spec-C V-Limited Toshi Arai Edition/ GTR/ Panda 100HP Pandamonium/ 316d

Back in the day when my shed-of-the-moment was parked in the driveway of my folks house, I used to nip out and stick a 1kw fan heater on in the car for 15mins before I left. Always cleared it superbly, although it was weird that the car cooled down for the next 10mins until the heater was able to produce anything.

Back in those days of course you had a manual choke 8)

Mark BT52 said...

Best way to warm it up is to gently drive it, not to leave it sitting there idling.

THIS.

HE is doing it wrong. Light loads will get the car up to temperature far quicker than idling it, which will mean the engine comes out of the cold enrichment cycle far quicker.

If you look in some new car owner's manuals, you’ll see that extended idling times take your car into the severe maintenance schedule. Police vehicles and taxis are good example of this and need far more frequent servicing as a result.

But it is even worse from cold - the reason being, that idling, even with a well tuned, and precise fuel injected engine, you don’t burn all of the fuel in the cylinders on initial start up, as you are running in the cold start enrichment part of the map. So the longer spent idling will mean the longer you will be in the cold start enrichment part of the map (as it warms up far slower this way), which over a period of time can reduce the life of the CAT. Extended idling can also cause the unburnt fuel to wash the oil from cylinders (again increasing wear), and also ends up (if done regularly enough) diluting the oil. The unburnt fuel will also cause carbon deposits on valves and in the EGR system.

Diesels are well known for bore wash problems (fuel washing oil from cylinders) to the point where some newer diesels have an idle-up feature that will increase idle and limit fuel if left idling for an extended period of time. These problems become magnified in cold weather, because fuel is harder to burn cold, so it is better to drive away ASAP.

--

Nordschleife - there's only two barriers to worry about - the ones on the left and the ones on the right!

There is a slight trade off in that if I scrape the screen, jump in, and drive off, then the screen fogs up on the inside before I reach the bottom of the hill, and I die in a fiery inferno.

--

Knackered old hairdresser's sh1tter

After every drive I empty the oil into a big kettle. This means that as I wake up in the morning I can have my breakfast, put on the kettle to warm the oil and then pour it into my cars engine.

Warm oil, no problems with circulation, DIC, etc

--

How about not having a sig at all?

Dr.(tbc) Alex said...

Surely the whole idea of Ford's quick heated windscreen is so that you can set off ASAP :lol:.

And what does he drive?

That's what I told him ;)

He drives a 2011 Subaru Forester.

Mike Rainbird said...

Mark BT52 said...

Best way to warm it up is to gently drive it, not to leave it sitting there idling.

THIS.

HE is doing it wrong. Light loads will get the car up to temperature far quicker than idling it, which will mean the engine comes out of the cold enrichment cycle far quicker.

If you look in some new car owner's manuals, you’ll see that extended idling times take your car into the severe maintenance schedule. Police vehicles and taxis are good example of this and need far more frequent servicing as a result.

But it is even worse from cold - the reason being, that idling, even with a well tuned, and precise fuel injected engine, you don’t burn all of the fuel in the cylinders on initial start up, as you are running in the cold start enrichment part of the map. So the longer spent idling will mean the longer you will be in the cold start enrichment part of the map (as it warms up far slower this way), which over a period of time can reduce the life of the CAT. Extended idling can also cause the unburnt fuel to wash the oil from cylinders (again increasing wear), and also ends up (if done regularly enough) diluting the oil. The unburnt fuel will also cause carbon deposits on valves and in the EGR system.

Diesels are well known for bore wash problems (fuel washing oil from cylinders) to the point where some newer diesels have an idle-up feature that will increase idle and limit fuel if left idling for an extended period of time. These problems become magnified in cold weather, because fuel is harder to burn cold, so it is better to drive away ASAP.


I think I might print this thread (particularly this) and show him the extent of how wrong he is doing it.

Nice explanation Mike 8)

The quickest way to warm an engine up is to bounce off the rev limiter from the off. Am I doing it wrong?

Mark BT52 said...

You'd have to be mad to do that, because this implies that your breakfast was ready before going out to sort out the car, and surely by the time you got back inside the milk would have made your cornflakes all soggy, or the cat would have eaten it.

Aside from the fact that the cat should be outside, this is the perfect amount of time for the milk to turn all chocolaty when eating co-co pops.

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Cheers,

Gwaredd

steelesigns.co.uk

I can pretty much guarantee you that if the engine is running, the oil at the bearing faces is up to temperature. It's the rest of the oil in the sump and the galleries that's a bit cold.

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Jobbo said...

Rev is correct, of course

Alex88 said...

He drives a 2011 Subaru Forester.

He's definitely DOING IT WRONG!

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