Warming up an engine?

[vit4]

Flicking through my car's handbook yesterday, found something that essentially said you shouldn't let the car tickover when you first start it up from cold, instead drive off immediately.

Now, I'd always thought this would be the other way around, where possible you should let it idle to warm up a bit. There's no reasoning as to why you shouldn't. So which is right?

[Uhura fighter]

Drive it with low revs for several minutes.

[Shaw Tarse]

I'm sure this has been discussed before?
I think get in & drive off won?

[MondeoMan1981]

An engine is designed to be used, it will get up to temperature quicker if you use it, just wouldnt thrash it at first.

Only time mine gets to warm up is when I'm clearing the windows in winter.

Other than that is, start, belt on, sort ventilation, choose cd, off we go.

Edited by MondeoMan1981 on Sunday 8th August 13:26

[retrorider]

imho the handbook is correct...

[vit4]

MondeoMan1981 said:

An engine is designed to be used, it will get up to temperature quicker if you use it, just wouldnt thrash it at first.

This makes sense I guess.

Learn something new every day

[GKP]

http://www.kenlowe.co.uk/pre-heaters/cars/index.ht...

[Jasandjules]

retrorider said:

imho the handbook is correct...

And mine. You drive off, but keep the revs down (i.e. the strain on the working parts) until the car is up to temp.

[plfrench]

vit4 said:

There's no reasoning as to why you shouldn't. So which is right?

In answer to this bit of your query, if I recall correctly, the reasoning behind not letting the car idle when cold is that the oil will sit at the bottom of the engine and not lubricate the top properly. By using low revs (less than 3k petrol / 2.5k Diesel) until warm, it allows the oil to be distributed around and to coat all the moving parts properly.

Edited by plfrench on Sunday 8th August 14:50

[kambites]

I think the answer is "it depends on the engine, so do what the handbook says". Your average road car engine is designed to be driven from cold. Some highly strung racing engines need to be warmed up carefully.

[Ozzie Osmond]

kambites said:

I think the answer is "it depends on the engine, so do what the handbook says". Your average road car engine is designed to be driven from cold.

Yes

kambites said:

Some highly strung racing engines need to be warmed up carefully.

I believe some even need to be heated and/or brought up to full oil pressure before being started.

[Menguin]

So rather than idling you could sit it at between 1 and 2.5k revs, to simulate driving? Or does that not work?

[Gad-Westy]

Menguin said:

So rather than idling you could sit it at between 1 and 2.5k revs, to simulate driving? Or does that not work?

Theoretically, that's a good idea. High revs with no load on the engine. In practice, your neighbours will come out and kill you to death before your temperature gauge has moved.

[Jasandjules]

Gad-Westy said:

Menguin said:

So rather than idling you could sit it at between 1 and 2.5k revs, to simulate driving? Or does that not work?

Theoretically, that's a good idea. High revs with no load on the engine. In practice, your neighbours will come out and kill you to death before your temperature gauge has moved.

IME (when it's the TVR at least) the neighbours come out and start saying what a lovely noise it makes (this helps if your neighbours have previously raced bikes)...

[Rammy76]

Gad-Westy said:

Menguin said:

So rather than idling you could sit it at between 1 and 2.5k revs, to simulate driving? Or does that not work?

Theoretically, that's a good idea. High revs with no load on the engine. In practice, your neighbours will come out and kill you to death before your temperature gauge has moved.

The thing is, the engine is better to have a bit of load on it to warm up faster, so driving off straight away is generally the favoured way, as long as you don't thrash it. This is especially so with diesels, I'd be sitting for hours waiting on mine to warm up otherwise!

[davepoth]

It's the running "on choke" that does it. The quicker the engine warms up the less enrichment the ECU needs to give it, which means that the cat will last longer, and also not coke up the engine.

[PhillipM]

Idling is one of the harshest conditions for an engine, you are much better off jumping in and running around at low throttle openings and <50% max revs to warm it up quickly and without undo load on the cam nose and crank bearings.

[The Riddler]

Rammy76 said:

Gad-Westy said:

Menguin said:

So rather than idling you could sit it at between 1 and 2.5k revs, to simulate driving? Or does that not work?

Theoretically, that's a good idea. High revs with no load on the engine. In practice, your neighbours will come out and kill you to death before your temperature gauge has moved.

The thing is, the engine is better to have a bit of load on it to warm up faster, so driving off straight away is generally the favoured way, as long as you don't thrash it. This is especially so with diesels, I'd be sitting for hours waiting on mine to warm up otherwise!

Nice warm engine, with cold trans. Yeah, good idea?

[s.m.h.]

Ozzie Osmond said:

kambites said:

I think the answer is "it depends on the engine, so do what the handbook says". Your average road car engine is designed to be driven from cold.

Yes

kambites said:

Some highly strung racing engines need to be warmed up carefully.

I believe some even need to be heated and/or brought up to full oil pressure before being started.

Many LMP engines need to be warmed with a water heater prior to crank for pressure and starting.
The GT2 Vipers were warmed with a space heater, we would get to the circuit, open the garage, fire up the heater then off for breakfast. Crank the oils round a bit when warm (the oil when cold caused so much drag it was capable of snapping the scavenge/oil pump drive in half) then crank for oil pressure, then start.

When I had my Ducati, well most of my bikes in fact, I would not ride off until the water temp was up to 40deg minimum. Otherwise the engine would still have been on choke and with a big twin, stalling at a junction isnt much fun.

I start the Hondas engine and drive off pretty much immediately, though in the winter I let it get some heat in it prior to driving off.

I cant see it being an issue in warming up prior to driving away, though a cold engine getting nailed wont last long.

This is what can happen to a race engine that is allowed to cool too much (fixing a problem mid-race) and not warmed prior to getting back to race-pace.. Engine was a NicMac V8

[Rammy76]

The Riddler said:

Rammy76 said:

Gad-Westy said:

Menguin said:

So rather than idling you could sit it at between 1 and 2.5k revs, to simulate driving? Or does that not work?

Theoretically, that's a good idea. High revs with no load on the engine. In practice, your neighbours will come out and kill you to death before your temperature gauge has moved.

The thing is, the engine is better to have a bit of load on it to warm up faster, so driving off straight away is generally the favoured way, as long as you don't thrash it. This is especially so with diesels, I'd be sitting for hours waiting on mine to warm up otherwise!

Nice warm engine, with cold trans. Yeah, good idea?

Hence why it's better to drive off straight away, no?