In this cold weather, should you allow an engine to warm up for a while before pulling away. (Ignore the fact that the windows are frosted up as that's a side issue)
Friend seems to think it's better to pull away almost instantly on a cold engine. I'm of the opinion that you should let the oil circulate, warm up and thin out a bit before moving off.
Who's correct? If an engine should be allowed to warm up on tickover then roughly how long should you allow?
sponix
I would need to check, but I'm sure the manuals for the last couple of cars I've owned have said you shouldn't leave the engine running before moving off. So start and move off if at all possible.
Your friend's right. You need to warm the engine up as quick as possible and it does that quickest when under load, not thrashing it to death obviously. When cold there's excess fuel splashing about washing oil of the bores and generally being unpleasant.
John
You only need to leave it long enough to get the oil round everything however, if you drive a car with a turbo, it's a good idea to let it idle for 30 seconds or so before switching it off.
The most important points are start up with no throttle (with a FI engine it will start fine with no gas) allow engine to idle for as long as it takes for the oil pressure light to go out (mostly near instantaneous), then drive off normally using 3000rpm as max revs and 25% throttle max until temperature gauge has at least moved off its stop.
Tim..
The message from snipped-for-privacy@email.com (sPoNiX) contains these words:
Straight off gently. In my case I don't even wait for the oil pressure to get to the turbo 'cos being an auto and several yards to the road I can just let it amble off on its own for the first few seconds. I'm ready to give it a little gas after about 15 seconds, which suits me fine. Then it's downhill with no gas for 150 yards, then flatish in a 30 zone with humps for half a mile so that's enough to allow more welly later if I need it.
The only time I'd give it a few minutes to warm up from stone cold would be if I had to do something like the climb from Lynmouth to Lynton from cold - then I'd give it half a minute.
The message from Conor contains these words:
Again, I'm lucky - the last thirty seconds at home involve trickling gently across the car park and reversing into the space - all done at idle.
Start it up, nip back inside for a crap & a cuppa tea. Give it a good 15 min and it will be nice & warm for you. That's how I've always done it, with no problems.
sQuick,..
A couple of decades ago when I worked for VW, I saw the results of a study they did into this question.
Their recommendation was clear: Drive off straight away, keeping the load light to medium, and keeping the engine RPM around the maximum torque (much lower than max power) range.
John
It would be in some areas...
Come out after 15 minutes and it would be 10 miles away and on fire....
: A couple of decades ago when I worked for VW, I saw the results : of a study they did into this question. : : Their recommendation was clear: Drive off straight away, : keeping the load light to medium, and keeping the engine RPM : around the maximum torque (much lower than max power) range.
I was just about to post that the owner's handbooks for my VW Type 2, and for a friend's Beetle, both said (I paraphrase) "Don't warm it up or treat it gently - give it some welly from the moment it starts".
Ian
*Never* allow an air-cooled lump to 'warm up' on the drive.
I found this out the hard way when the big end bearing welded itself to the crank.
You want it warming up quickly so that the extra petrol for cold running has as little chance to wask the bores off. Start it up, let it idle for a few seconds after the oil light goes out to make sure there is oil up in the top end and drive off. Keep the revs up so it's not lugging, but don't rev the nuts off it until you are into the normal temp range or if there's no temp gauge when the heater is delivering hot air.
Or if it is on a public road you'll have a nice policeman waiting for you...
If the oil hasn't warmed up (And thinned) wouldn't it stress the oil pump/seals of you drive harshly?
sponix
What about older cars?
What concerns me is the viscosity of oil when it is cold.
sponix
That's way too high on many cars. Around 2000 rpm is ideal.
Or in parts of Glasgow run by the City Council, you could have a nice fine as well. But not in parts of Glasgow not run by the Council. (-:
In message , John Henderson writes
That would be 5900 rpm on my car.
SteveH ( snipped-for-privacy@italiancar.co.uk) gurgled happily, sounding much like they were saying :
Yebbut, that was a bike.
Air-cooled cars have ducting and a fan, so even stationary they get some cooling air passed over them.
I'm always very careful about running a 2cv engine without the fan on and the vehicle stationary.
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