CSR water temperature

[Cows Aloud]

Had a great day doing the Tafia Fish & Chip run however whilst in a traffic jam in Brecon water temp reading on stack went up to 108c. As soon as we were moving again dropped back to 85c.When stopped we let the temp go to 105c but couldn't hear the fans running. Any suggestions as to checking fans are ok and at what temp they should come in?

Reading the manual on returning home it states optimum running temp 110c?

This seems very high?

[tbird]

CA

If its any help my Fans usualy kick in somewhere between 98 and 102 on the stack, in Germany last year, stuck in traffic on a hot day and the water was up to 110 with fans running and the oil temp not far behind, I wasn't happy but to be honest there were no problems, I had a chat with CC when I got back and they assured me that wasn't a problem and the CSRs run hot anyway. Having said that you said you couldn't here the fans running stationary at 108, that would concern me, you will definitely here them when they kick in if you are stationary with hood down. even at tickover in the garage (doors open) or on the drive the temp will get high enough to kick in the fans, so if you take off nose cone you will see if they start up by 110

Like yours, normal running with plenty of airflow, no fans and about 85C

 

welcome to BC btw

 

Tim

 

 

Edited by - tbird on 26 Apr 2012 17:03:25

[charlie_pank]

I don't know if the fan is ECU or temp-switch controlled on a CSR. I'll assume that it is temp-switch controlled like on my roadsport.

 

This is basic fault-finding:

 

Check the fan's working by attaching 1 fan terminal to earth and the other to (+). If it runs, your fan is fine.

 

Next, try shorting the terminals of the thermoswitch, if this makes the fan run, then wiring to thermoswitch is fine.

 

Next check that radiator is full and water is covering thermoswitch if it isn't then the thermoswitch won't be able to tell the temp of the coolant

 

To check the thermoswitch, take it out of the radiator (you'll have to drain the coolant to below the level of the thermoswitch) and stick it in a pan of water with a thermometer. Check the resistance across the terminals at room temp. then check again at the temp the switch is supposed to operate.

 

If all the above is working fine, then maybe your thermostat isn't opening or your temp gauge is mis-reading etc... etc...

[tbird]

Thread here on temp and sender and fan fault which might be useful

 

Tim

[mic]

Fans are ECU controlled

 

[Cows Aloud]

Thanks for the helpful replies. Very impressed with rapid response and advice !!

Adrian

 

[Bio]

Hi Adrian,

I was that pesky VX behind you going across the mountains. 😬

It must be the feed to the fans (or the return) as you say both fans are not working. Is there a fuse just for the fans 🤔

 

John

[charlie_pank]

Hmm, makes it more fiddly if it's ECU controlled. You'll have to find out at what temp the ECU should turn the fan on. You can do a lot of the same tests as I described to check though - the ECU will control the fans through a relay - so you could short the terminals on the relay to check its operation etc... if you find out the resistances of the ECU's temp sender at different temps (this'll be in the spec of the part itself - perhaps ask Caterham Cars?) you can whip it out and stick it in a pan of water with a thermometer and a multimeter to make sure the ECU is reading the right temp.

[ACJ]

If you have knowledge of the easymap software and a CAN adapter lead I think you can activate the fan controller from the ECU. From memory the MBE Cosworth ECU has a lock on it which means it won't work with the download from the MBE / SBD website. This will at least answer if you have a wiring issue / problem physically with the fan or an input issue with the temp sender.

 

Additionally, does your car have a stack dash? If so I think the car uses seperate senders for the dash and ECU. I think one is in the casting bolted to the back of the head and the other is in the ali water tube running to the rad. They do suffer from reading differently so the dash will display a higher reading than the ECU is seeing, hence the fans seem later on coming on.

 

Hope this helps

[Cows Aloud]

Thanks for all your suggestions. Today having time to test out the temperature, the fans are in fact working fine but they come in at 106C! Seems high to me but presumably not a problem after all!

Adrian