Discussion
Just wondered what temperatures people have seen their cars get to...
After sitting in the sunny queues at Le Mans, my Chimaera (95, 4.0 HC) was quickly climbing to 100 degrees even with the fans on continuously and as I'm off for a 2 week tour of the South of France in September, I just wondered whether I should be concerned... The car seemed to stabilise a bit at 100 degrees, but slowly crept over. I saw a maximum temp of around 103.
I've had a lower temp otter switch and new radiator fitted, but the fans just don't seem to provide adequate cooling air flow in hotter temperatures. Any advice?
Thanks,
Ross
After sitting in the sunny queues at Le Mans, my Chimaera (95, 4.0 HC) was quickly climbing to 100 degrees even with the fans on continuously and as I'm off for a 2 week tour of the South of France in September, I just wondered whether I should be concerned... The car seemed to stabilise a bit at 100 degrees, but slowly crept over. I saw a maximum temp of around 103.
I've had a lower temp otter switch and new radiator fitted, but the fans just don't seem to provide adequate cooling air flow in hotter temperatures. Any advice?
Thanks,
Ross
quote:
People seem to like the Modwise two stage fan gadget mentioned on this list in the last day or two - maybe that'll help.
I thought about this after seeing GreenV8S's review. The problem seems to be with the fans though as they simply don't provide enough of a cooling effect in hotter temperatures.
What sort of temperature would you consider pulling over and letting the car cool off? I stopped when the needle passed 100 degrees (around 103)...
quote:You could fit some thermal wrapping on the header manifolds - this should help a bit (Demon Tweeks sell it I believe). Have you checked that your thermostat is opening completely? What temperatures do you normally see in Britain?
The car seemed to stabilise a bit at 100 degrees, but slowly crept over. I saw a maximum temp of around 103.
I've had a lower temp otter switch and new radiator fitted, but the fans just don't seem to provide adequate cooling air flow in hotter temperatures. Any advice?
Thanks,
Ross
cheers,
Craig
quote:The Mod-Wise kit helps with heat soak but won't increase the cooling capacity at all. The spoiler (if it does anything) only works at speed where the temp should not be an issue. If you have air con turn it off as that helps a lot. It could be the guage is out so it might be worth using a temp gun to see what the temps actulaly are. Could also be a partially blocked rad or one that has had a slighly less efficient core fitted. Could be that the fan(s) is on its way out and is not as effeicient either. Had that once on the 520 when one of the Kenlowes died.
I thought about this after seeing GreenV8S's review. The problem seems to be with the fans though as they simply don't provide enough of a cooling effect in hotter temperatures.
Personally if the temps start to get over 100 ish in traffic, time to pull over as this really is not where the car want to be.
Steve
Surely 103 isn't going to cause it a problem is it? When the cooling system is under pressure the water won't be actually boiling until a much higher temperature. My fireblade is the only thing I've got with an accurate temp guage and it sits happy at 105 in traffic and run normally at 81.
Mark
Mark
quote:
You could fit some thermal wrapping on the header manifolds - this should help a bit (Demon Tweeks sell it I believe). Have you checked that your thermostat is opening completely? What temperatures do you normally see in Britain?
Hi Craig, in Britain I normally see temperatures around 80 degrees (fans cycling in and out) on a normal drive and up to low/mid 90s in London. The fans do cut in and out quite frequently so I presume the thermostat is working ok...
I don't know what sort of temperature I should start to get concerned. I was just aware that the fans did not seem adequate in the heat at Le Mans and thought it might be worse in the South of France (although September might be cooler?). Probably just a bit of tvr-paranoia, but thought I'd check...
Did anyone else who went to Le Mans experience soaring temps? I ended up taking the front number plate off and stashing it in the boot - the Gendarmes didn't seem to care...
Whilst obviously you can not increase the cooling capacity with two stage cooling, what you can do is replicate the cooling effect of higher speeds at much much lower speeds by having the fans on at half speed. They come on at half speed way,way before the full speed so at least "something" is acting to begin the cooling effect, rather than relying on forward motion.
Imagine the engine reaches its operating temperature and opens the water thermostat, unless you are to travel at 55mph, the coolant temp will begin to rise. With fans on at half speed at 30mph has the same cooling effect as motoring at 60mph. If all is well the car initially, half speed fans after the full speeds have gone off has to be an advantage. While stationary keeping the air moving from under the bonnet is also an advantage.
Imagine the engine reaches its operating temperature and opens the water thermostat, unless you are to travel at 55mph, the coolant temp will begin to rise. With fans on at half speed at 30mph has the same cooling effect as motoring at 60mph. If all is well the car initially, half speed fans after the full speeds have gone off has to be an advantage. While stationary keeping the air moving from under the bonnet is also an advantage.
In many of the handbooks, the instructions are to stop if the needle gets into the red which makes life a little tricky as there is no red area. Dug in my TVR archives and quote" Should the guage register between 100-110 and remain in that position, stop the car immediately and switch off the engine. Investigate and rectify the cause."
That indicates to me that your car has a problem or that the temp gauge may be slightly inaccurate. If it is a real problem then it is a question of working through the obvious things, I don't know how old the car is but there have been several changes particularly in the fan front and so on. Are there any air locks,? Is the fluid leaking somewhere? There are many things to go and check. Is the thermostat sticking? Is it the right one? Is the fan belt tension right? Is the water pump on its way out?
Fitting spoilers etc are not going to solve the fundamental issue of the car overheats when stood still in traffic for X minutes when the ambient heat is X degrees. That is purely down to cooling capacity and many many cars don't do this so the conclusion must be that something is wrong.
I would chcek that the guage is accurate. It may simply be reading a few degrees out and the car is behaving itself. If it is't then start checking that there is not a problem.
Steve
www.tvrbooks.co.uk
>> Edited by shpub on Wednesday 10th July 19:57
That indicates to me that your car has a problem or that the temp gauge may be slightly inaccurate. If it is a real problem then it is a question of working through the obvious things, I don't know how old the car is but there have been several changes particularly in the fan front and so on. Are there any air locks,? Is the fluid leaking somewhere? There are many things to go and check. Is the thermostat sticking? Is it the right one? Is the fan belt tension right? Is the water pump on its way out?
Fitting spoilers etc are not going to solve the fundamental issue of the car overheats when stood still in traffic for X minutes when the ambient heat is X degrees. That is purely down to cooling capacity and many many cars don't do this so the conclusion must be that something is wrong.
I would chcek that the guage is accurate. It may simply be reading a few degrees out and the car is behaving itself. If it is't then start checking that there is not a problem.
Steve
www.tvrbooks.co.uk
>> Edited by shpub on Wednesday 10th July 19:57
quote:
Your's is an M reg car? Does it have the single or double fan arrangement?
Steve, I've got twin fans and both seem to be working ok. The radiator was replaced in January and then David Batty fitted a lower temp otter switch at a major service in/around April. I haven't checked for air locks so will double check this over the weekend...
I'm going to get the car serviced and double checked before I leave, so that should give me peace of mind... Thanks for all the suggestions, looks like I've got a weekend double checking things to look forward to!
Yes it is possible. Personally don't think it is worth it. Doesn't reduce the engine temp much if at all. Doesn't stabilise the oil temp much either as the oil doesn't usually get overheated anyway.
If the car is being thrashed within an inch of its life yes, worth considering.
Based on the 520 with oil cooler and oil temp guage.
Steve
>> Edited by shpub on Tuesday 16th July 07:37
If the car is being thrashed within an inch of its life yes, worth considering.
Based on the 520 with oil cooler and oil temp guage.
Steve
>> Edited by shpub on Tuesday 16th July 07:37
'I know its not boiling over, just dumping. Anybody similar.'
Yes, mine will drop a bit - but only sometimes and only when I move the car 10 yards into the garage after a good run. Doesn't do it when I stop after the long run, only after the 10 yard bit. Bizarre. I suppose the underbonnet temperatures have crept up while it was parked. Never have managed to see where it's coming from though - any idea folks?
>> Edited by simpo one on Tuesday 16th July 09:57
Yes, mine will drop a bit - but only sometimes and only when I move the car 10 yards into the garage after a good run. Doesn't do it when I stop after the long run, only after the 10 yard bit. Bizarre. I suppose the underbonnet temperatures have crept up while it was parked. Never have managed to see where it's coming from though - any idea folks?
>> Edited by simpo one on Tuesday 16th July 09:57
My Griff 500's guage been up in the high 90's and touches 100. I went back to the dealer, who checked the coolant temp with a digital meter. It read steadily between 83 and 87 during a half hour idle. The dealer told me it's the sender or the guage as the cooling system seems fine. They fitted a low value resistor in series to lower the reading slightly and will investigate more next service. Hope this helps.
Ross
any news on your weekend of checks? Although i have the "new" two fuse, two relay set up, i was a total of 11 amps down through the original wiring on full speed fans. By going to a "good supply" i now have the full supply. My fans now roar rather than purr. Just a thought! Maybe yours is not so simple.
Oh and another point is now if the fans were on when i pull up and turn off, they stay on until the temp has gone down. Of course they can not come back on again to set the alarm off.
>> Edited by david beer on Tuesday 16th July 18:59
any news on your weekend of checks? Although i have the "new" two fuse, two relay set up, i was a total of 11 amps down through the original wiring on full speed fans. By going to a "good supply" i now have the full supply. My fans now roar rather than purr. Just a thought! Maybe yours is not so simple.
Oh and another point is now if the fans were on when i pull up and turn off, they stay on until the temp has gone down. Of course they can not come back on again to set the alarm off.
>> Edited by david beer on Tuesday 16th July 18:59
quote:
Ross
any news on your weekend of checks? Although i have the "new" two fuse, two relay set up, i was a total of 11 amps down through the original wiring on full speed fans. By going to a "good supply" i now have the full supply. My fans now roar rather than purr. Just a thought! Maybe yours is not so simple.
Oh and another point is now if the fans were on when i pull up and turn off, they stay on until the temp has gone down. Of course they can not come back on again to set the alarm off.
David, thanks for the email. The only thing I discovered over the weekend was that I was a little low on coolant. I've now topped this up and seem to be running a bit better.
How easy is it to fit your kits? I'm quite interested after having a look at your web site... If the current to the fans is suffering due to the original wiring/set up and your kit fixes this, then I'm definitely interested. Which kit reduces the resistance on the circuit to the fans?
Interesting that your fans stay on after the engine has been turned off as well... I was wondering whether any damage could be done to the engine if it is turned off when hot and the fans stop as well. Surely there is then no cooling so the temperature under the bonnet could increase even further?
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