K Series Cooling

[David Hopkins]

First 1000 miles has seen my car overheat 5 times , water out of expansion tank and rad , J hose still cold . New thermo switch for fan and thermostat make no diference .

 

Caterham didnt fix it a the build check and seem baffled .

 

Have lifted front of car during bleed which seems to improve things but gauge still has excursion into 100+ before fan cuts in so I am still not confident with the car .

 

What is the exact procedure to ensure I fix this .

[Bob Corb]

Just out of interest, do you have a heater or not?

 

I don't. I just filled the coolant with the car level and then raised the front a pulled the bleed screw out of the top of the rad. Carried on topping up and squeezing all the hoses. I did have to top up by 1cm's worth in the header tank when it started up for the first time. The coolant temperature has only gone over 85° by a small amount when it gets a good pasting down a country lane. Car has now been running for 1500miles (in 4 weeks).

 

Bob

[ashaughnessy]

I'm glad I don't have a k-series - this is the umpteenth thread about k-series overheating. Try searching old Tech-Talk threads, there's all sorts of depressing information about repeated replacement of fan switches, thermostats, etc.

Anthony

[pie_boy69]

When bleeding your system you dont have to lift the front all you have to do is give it a good blow( if you pardon the expresion)

Fill the system, remove the bleed then blow hard into the filler and wait for the fluid to come out.

Have you tried running with no thermostat?

Have you checked that the fan is turning the right way when on?

 

 

Keith Pickering

now superlight less

[Dartmoor7]

It's not a K-series problem, it's a Caterham problem.

Otherwise we wouldn't be able to move for all the Metro's,200's,400's,etc, parked at the side of the road.

[Tin Man]

Sounds like an airlock to me. have you tried jacking the front end up before filling. If you have a heater fill the the upper hose with your finger over the heater inlet to stop it drawing in air. Is the temp gauge reading correct? A bad earth on the sender can make it read very high. Good luck.

 

 

[murph7355]

If you're not getting steam any more, it could be that the gauge isn't reading accurately (if the temp drops back down, where does it drop to?). You might want to take a reading at the fan switch with a reliable thermometer and see where it's cutting in. I think it should be about 95degC.

 

Having had the privilage of meeting Keith I wouldn't argue with him wink.gif However I'm not sure I'm man enough to get my mouth round a hot expansion tank, and am not convinced I could get enough wind up to blow the air out (though I do have friends who would scoff at both comments)! Certainly not without drinking half a pint of Comma's finest.

 

The "jack up the front" piece (heating the system through and bleeding with the heater fully open if you have one) worked perfectly for me.

[murph7355]

I am *100%* sure I pressed the button once! Honest.

 

Edited by - Andy Murphy on 5 Oct 2001 22:49:59

[mikehoile]

Ive also joined the overheating club-problem was my rad fan switch didn't whilst on holiday in France this year. Whilst there was no engine damage, am not sure quite what caused the problem except the that Caterham advised that they had had a faulty batch of switches-they seem to get several of these on different items from time to time according to members,-Caterham advised to take out the thermostat which enabled us to carry on as it seems that the stat was buggered and the header tank ruptured along a side seam probably due to excess heat. in fairness caterham have now put in a new stat and I managed to get a new VW fan switch in France. Air locks are a pain in the .... to get out sometimes

[Red SLR]

Dave

 

I have just returned from my garage trying to fix this EXACT same problem!!!!

 

I have been, with out much success trying to fix it for about 2 months now.

 

I am quite sure it is air in the system though. I have tried 3 stats and 3 fans switches now and they have not really helped.

 

In my opinion air is getting trapped in the top of the rad and no allowing water to flow round to the stat and thus the stat does not open and the water just gets hotter and hotter.

 

I would try the following. Needs 2 people really.

 

Run car upto temp on flat surface. Jack car up, remove bleed bolt on top of rad. Then remove filler on exp tank and stick a hose pipe in there. Leave engine running.

 

Then let the hot water run out of the top of the rad until stone cold water comes out. Then once water goes cold replace bleed bolt and exp tank cap.

 

Turn off engine and lower car.

 

Next run car upto temp again and see how hot it gets, dont let it go over 100 though, then *slowly* unscrew the bleed bolt. You should start to hear air come out, if water comes out then you are ok. Then once water comes out tighten the bolt up and check temp. Top up exp tank once the car has cooled down.

 

You may need to do this a couple of times to get all the air out.

 

I did this 3 times and managed to get my car down from 100c+ to 83c max.

 

Dont forget to put some anti-freeze in also....(other wise you will have to start all over again)

 

My bottom hose only gets warm after the car has been running for about 10 mins and is upto just over 80c. This is because the std stat is 88c and only starts to open when the water is just over 80. You may want to get a lower stat, maybe 82c.

 

I would not advise running without one.

 

If this solves your problem I would advise you check the car every few weeks just incase.

 

 

Hope this helps.

 

Simon.

 

X777CAT

[Red SLR]

Ps - see my post called over heating AGAIN.

 

I have moved it near the top.

 

Simon.

 

X777CAT