End of a drive - resting/cooling an engine down?
Discussion
Hi all.
I have been wondering this for a while now - when you have been for a drive, be it to a large shopping centre, or a motorway slog, or a nice b-road attack; do you 'rest' the engine afterwards when you arrive at your destination or do you just shut down as soon as you arrive?
I have always - and I don't know why - let the engine idle for a minute to 1.5 minutes to let the engine 'rest' and to shed some heat. Other people I've seen just pull up and shut down asap.
I remember reading in a vehicle manual a while ago that it is advisable to give the engine a rest period for the engine to catch its breath prior to shut down (although this was for a Fiat...).
In my mind, it would make sense especially after a hoon somewhere. Yet I seem to be alone in this thought from what I've seen?
So... what do you do? Arrive and shutdown, or arrive and let the engine idle for a bit?
For simplicity, let's talk about your *average* car (petrol, na), not some supter-tunned turbo-nutter machine etc.
I have been wondering this for a while now - when you have been for a drive, be it to a large shopping centre, or a motorway slog, or a nice b-road attack; do you 'rest' the engine afterwards when you arrive at your destination or do you just shut down as soon as you arrive?
I have always - and I don't know why - let the engine idle for a minute to 1.5 minutes to let the engine 'rest' and to shed some heat. Other people I've seen just pull up and shut down asap.
I remember reading in a vehicle manual a while ago that it is advisable to give the engine a rest period for the engine to catch its breath prior to shut down (although this was for a Fiat...).
In my mind, it would make sense especially after a hoon somewhere. Yet I seem to be alone in this thought from what I've seen?
So... what do you do? Arrive and shutdown, or arrive and let the engine idle for a bit?
For simplicity, let's talk about your *average* car (petrol, na), not some supter-tunned turbo-nutter machine etc.
I think most modern cars will continue to run a fan if needed after you have shut down.
I do avoid putting in the handbrake though if I think the discs might be hot still to avoid warping them – but I've no idea if this is still a good idea or some old habit that's not required with modern cars.
I do avoid putting in the handbrake though if I think the discs might be hot still to avoid warping them – but I've no idea if this is still a good idea or some old habit that's not required with modern cars.
I got in the habit of letting the car run gently for a minute or two when I stop when I had my Renault 5 GT Turbo and tend to do so to this day, but I'm not sure it really has any beneficial effect in most cars.
I think the idea was it let cooler oil circulate around the bearings on the turbo...
M
I think the idea was it let cooler oil circulate around the bearings on the turbo...
M
We ve got a zetec s fiesta oil burner, trip to the motherin laws 3/4 times a yr is around 130ish miles always between 70/80 most of the way but when we arrive im like yourself and i never know why but ive always left it ticking over, but thinkin about it now its probably only a minute if im honest whilst i gather all my sh*t up, phone, wallet, bottle of pop etc then go in and say our hellos and then come out and unpack the car. where as work for me is a 30 mile each way drive and i rarely do it then if at all.
You shouldn't need to worry about the handbrake or allowing an engine to cool after you've been for a thrash unless your house is at the end of the road you've been caning.
The time is takes to get from B-Road to house should be enough for a cool down.
That said, apparently it is a good idea to leave a turbo engine running for a while to keep oil pumping but this is quite old advice.
The time is takes to get from B-Road to house should be enough for a cool down.
That said, apparently it is a good idea to leave a turbo engine running for a while to keep oil pumping but this is quite old advice.
Snowboy said:
I think most modern cars will continue to run a fan if needed after you have shut down.
I do avoid putting in the handbrake though if I think the discs might be hot still to avoid warping them – but I've no idea if this is still a good idea or some old habit that's not required with modern cars.
That's good to know. Question: is the coolant still 'circulating' (I have no idea how it works!)? I have noticed on a few older cars everything would stop asap when I turn off. Perhaps idling was a throwover from older cars that didn't actively keep the fan on to aid cooling??I do avoid putting in the handbrake though if I think the discs might be hot still to avoid warping them – but I've no idea if this is still a good idea or some old habit that's not required with modern cars.
marcosgt said:
I got in the habit of letting the car run gently for a minute or two when I stop when I had my Renault 5 GT Turbo and tend to do so to this day, but I'm not sure it really has any beneficial effect in most cars.
I think the idea was it let cooler oil circulate around the bearings on the turbo...
M
That's interesting re the oil circulatin. I imagine the same would apply to the engine itself?I think the idea was it let cooler oil circulate around the bearings on the turbo...
M
Also does this train of thought apply to turbo diesel cars (I imahgine it does).
On this note, how does one idle wth an automatic where some manufacturers specifically doesnt recommend idling in P or N for any period of time/frequently. Something to do with cooling?
Dangerous Dan said:
That's interesting re the oil circulatin. I imagine the same would apply to the engine itself?
Also does this train of thought apply to turbo diesel cars (I imahgine it does).
On this note, how does one idle wth an automatic where some manufacturers specifically doesnt recommend idling in P or N for any period of time/frequently. Something to do with cooling?
The idea with turbocharged cars is that it is to allow oil to circulate, whilst it cools down, as if you switch the engine off straight away after a spirited drive, the very hot oil is trapped in the turbo and the bearings within the turbo can overheat. To do any real damage, you would need to be ragging the nipples off it, and then switch the engine off straight away. 95% of the time, people don't do this.. just a 5 minute relaxed drive after a spirited drive is more than enough to allow the oil to cool. Also does this train of thought apply to turbo diesel cars (I imahgine it does).
On this note, how does one idle wth an automatic where some manufacturers specifically doesnt recommend idling in P or N for any period of time/frequently. Something to do with cooling?
BriC175 said:
Dangerous Dan said:
That's interesting re the oil circulatin. I imagine the same would apply to the engine itself?
Also does this train of thought apply to turbo diesel cars (I imahgine it does).
On this note, how does one idle wth an automatic where some manufacturers specifically doesnt recommend idling in P or N for any period of time/frequently. Something to do with cooling?
The idea with turbocharged cars is that it is to allow oil to circulate, whilst it cools down, as if you switch the engine off straight away after a spirited drive, the very hot oil is trapped in the turbo and the bearings within the turbo can overheat. To do any real damage, you would need to be ragging the nipples off it, and then switch the engine off straight away. 95% of the time, people don't do this.. just a 5 minute relaxed drive after a spirited drive is more than enough to allow the oil to cool. Also does this train of thought apply to turbo diesel cars (I imahgine it does).
On this note, how does one idle wth an automatic where some manufacturers specifically doesnt recommend idling in P or N for any period of time/frequently. Something to do with cooling?
I always rest the car at idle before switch off. It's a must for my MR2! If I've come off the motorway or some really hard use I'll give it three minutes at the most. Usually a little less if I've just come off the road and thirty seconds if I've had to slowly creep into my destination.
Turbo Timers are popular with a lot of older performance car owners. That said, I don't use them, not just because of quitting offences but because I don't like the idea of the engine running with the keys out, or even the idea of securing the car in a private area and walking away with the engine still going. Mind you, a turbo timer is always appreciated when buying a used car as it means someone has decided to spend a bit of cash looking after the turbo prior to you getting it!
Turbo Timers are popular with a lot of older performance car owners. That said, I don't use them, not just because of quitting offences but because I don't like the idea of the engine running with the keys out, or even the idea of securing the car in a private area and walking away with the engine still going. Mind you, a turbo timer is always appreciated when buying a used car as it means someone has decided to spend a bit of cash looking after the turbo prior to you getting it!
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