overheating on a run

[nigel99]

the temp on my S1 goes into the red on a long run, i've had a new radiator an 82 degree thermostate, new pressure cap and new hoses in recent months. but when i go out the engine warms up fan cools it down, engine warms up again fan cools it down again, but each time the temp gets a little bit hotter until i,m always running in red with the fan on. does not seem to be any leaks, but after a long haul could end up putting half a pint back into swirl tank of water that has boiled off. anybody got any idea's or advise before i loose the head and put it in autotrader

[GreenV8S]

Have you bled the rad? How old is it? They can get silted up on the inside and clogged on the outside and gradually lose their effectiveness, but start by making sure the rad has been bled because an air lock in the rad will cause those symptoms.

[bills1]

For the S1 it is very critical to have the system up to pressure but not too high and correct rad cap essential.
It needs to be a long reach to hold the pressure, if the system does not get up to pressure it will blow the water out with a lower boilig point.
Firstly try reusing the old cap, it may be old but worked and using it will confirm where the problem is.

I use Quintin Hazel FH49 and now have no probs apart from having to top the water every so often(500miles).

If this doesn't solve it you could be losing pressure via the smallest leak so give it all a good check when hot.

best of luck and let us know how you get on.

PS Of course you are putting the pressure cap on the swirl tank. This is also essential for the 2.8

[nigel99]

first problem was with water leaking from top of swirl tank, so replaced cap,local TVR specialist pressure tested found leak in rad so replaced, used a new rad from a chimera which he said would be fine.ok for a while then started to get hot on long runs so changed thermostat, but still getting hot. will bleed rad to make sure, if no joy will take back for a pressure test, but am a bit worried it might be head gasket, altought no sign of water in oil

[mycroft]

Probably not your problem but i think most of the early cars had the rad mounted behind the rad , if it has been wired up to blow this can dramatically reduce cooling effect rather than help it , later cars were built with fan in front of the rad , i can only assume cos it worked better .sorry if this is obvious but as you have a build up in temp the longer you run it could be something like this .

[Ray S]

Have a similar problem with mine but not as bad as yours sounds previous owner fitted an override switch for fan.I think a lot of the problem is to do with the angle of the rad,quite a lot of cooling air must be deflected downwards. I'm going to try fitting some deflection fins in front of my rad to force more air through.Will let you know if its a success.Ray

[niels]

Maybe it's not getting enough air.

My S1 overheated when I first got it 3,5 years ago. I removed all the fly mesh in the air-intake. It was clogged up with paint and rubbish.

Now the cooling is perfect. Even still with the old radiator.

Niels

[ketvrin]

nigel99 said:

but after a long haul could end up putting half a pint back into swirl tank of water that has boiled off. anybody got any idea's or advise

This may sound daft but you are not just putting water in alone are you ? Antifreeze has summer cooling properties as well as anti freezing winter properties so you need to keep the mix correct when you top up... sorry if thats obvious but...

failing that maybe these will help:

http://cgi.ebay.co.uk/TVR-Chimera-radiator-cooling...

good luck anyway

K