Letting the car cool down
Discussion
Ok i've just got HGF on the Elise but there is one thing I don't understand regards preventing it in the future
Lots of people talk about letting the car cool down after a track session or similar by leaving it running stationary for a while, but all I see happening is the temperature rise to 100+ and the fan cut in, or is the idea that if you switch it off the coolant pump stops leaving a hot engine with less cooling?
Surely its better to take the car for a gentle run to let air into the rad and maintain 87 or so then switch off?
Lots of people talk about letting the car cool down after a track session or similar by leaving it running stationary for a while, but all I see happening is the temperature rise to 100+ and the fan cut in, or is the idea that if you switch it off the coolant pump stops leaving a hot engine with less cooling?
Surely its better to take the car for a gentle run to let air into the rad and maintain 87 or so then switch off?
in an ideal world, it would be great to have a few slow miles in a cool breeze before you switch off ...in reality it will likely make bugger all difference to getting HGF again im afraid.
HGF on the K is well documented, I really wouldnt worry about, just use it like a normal car - its a mass prodcution shopping car engine after all, if you go on track, get an oil cooler and yes, do some cool down laps, but other than that, accept it may cost you £500 every 30, 40, 50K miles...pot luck really !
HGF on the K is well documented, I really wouldnt worry about, just use it like a normal car - its a mass prodcution shopping car engine after all, if you go on track, get an oil cooler and yes, do some cool down laps, but other than that, accept it may cost you £500 every 30, 40, 50K miles...pot luck really !
Yep, as you live in the South East you probably know that many a journey can end with the engine above 95 degrees. What I'll do is let the fan cut in, then wait until the temp bottoms out - it's normally 95-96 degrees - then cut the ignition. Just don't come screeching up to your drive and stop the engine and you should be fine.
Davis... the thing is if you switch it off right after a track session, the heat soak into the coolant ends up with the engine boiling the coolant inside the bloc and popping the head gasket (possibly).
I've noticed in the past, restarting my car 10 minutes after a track session the temperature reading up around 115!
Sure if you leave it parked, idling, the temperature of the coolant will creep up until the fan cuts in as it sucks the heat out of the engine, this is better than just switching it off.
Best solution by far is to do a good few cool-down laps to allow the radiator to breathe and suck out the heat-soak... alternatively, install a manual fan-override switch so that when you come off the track you can leave it idling for 5 minutes with the fan going to suck out the heatsoak instead of having to wait for the temperature to rise.
In the absence of either, try leaving it parked up with the doors open and the ventilation fan/heater on full blast... it's not much but it helps
I've noticed in the past, restarting my car 10 minutes after a track session the temperature reading up around 115!
Sure if you leave it parked, idling, the temperature of the coolant will creep up until the fan cuts in as it sucks the heat out of the engine, this is better than just switching it off.
Best solution by far is to do a good few cool-down laps to allow the radiator to breathe and suck out the heat-soak... alternatively, install a manual fan-override switch so that when you come off the track you can leave it idling for 5 minutes with the fan going to suck out the heatsoak instead of having to wait for the temperature to rise.
In the absence of either, try leaving it parked up with the doors open and the ventilation fan/heater on full blast... it's not much but it helps
I've installed the fan switch but only use it when tootling back to the parking space (but NOT when on the track.) I race a Mini Cooper and we have a capillary temp gauge in the head. You'd be amazed at the real-time heat soak (with this gauge it's displayed constantly without ignition on) and so we always return to the car every 5 mins, start it up and hold at 2000rpm for 20 secs. It drops 10 degs at least every time. Do that once or twice and it'll help. Even if the electric fan is on, the waterpump will only pump cooled water from the rad to the head with the engine on! I now also do it for the Elise on trackdays because I too am paranoid about the gasket.
lee111s said:
I've not been above 100 but I've never heard my fan kick in :/
should I be worred? (s1 111s)
No. The fan doesn't generally cut-in 'til around 102-105, as far as I know, which will explain why you haven't heard the fan. Mine cuts-in at an indicated 104. should I be worred? (s1 111s)
Leave it idling for a while when you get home. Then, if you haven't heard the fan kick-in by 105 take it for another drive straight away to cool it down... and only then can you start worrying about your fan not working!
Edited by Breezer182 on Sunday 30th November 03:36
Thrashing an engine and then just switching it off will likely knacker any engine as hot spots build up, the coolant overheats, then boils and pops your gasket. I generally try to get a proper cool down lap in and then leave the engine running at low revs for a few minutes afterwards. The K series is maybe worse than others according to internet statistics, but you should cool any engine down properly anyway. Having said that, there are a lot of k series in caterhams which get subjected to appalling abuse but last rather well. Maybe it's all just b*llocks and it's luck of the draw.
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