Coolant Fan Cycling

Chris Kennedy · Oct 20, 2018

I was testing the coolant fans on my new MKII this morning to make sure they came on automatically and, yes they did, but noticed they cycle on a tight pattern---- just under 15 seconds on, then just under 15 seconds off, then 15 seconds or so on etc. I suspect this is correct, as override feature and air conditioner operation turns them on continuously. Am I correct about this? I am making good progress learning about and working with the car--- jacked up the car and changed the tire myself, adjusted rear clamshell for smooth open/close etc.
Thanks,
Chris

Roger Allen · Oct 20, 2018

Chris Kennedy said:
I was testing the coolant fans on my new MKII this morning to make sure they came on automatically and, yes they did, but noticed they cycle on a tight pattern---- just under 15 seconds on, then just under 15 seconds off, then 15 seconds or so on etc. I suspect this is correct, as override feature and air conditioner operation turns them on continuously. Am I correct about this? I am making good progress learning about and working with the car--- jacked up the car and changed the tire myself, adjusted rear clamshell for smooth open/close etc.
Thanks,
Chris

Hi Chris, I spent much time testing autofan switches. In the end fitted a high temp variant to cover the times I forgot to handle it manually! My RCR with about 375bhp was tricky to get stable with water temp. But fitting a pair of Kenlowe high output fans cured the issue impressively. Didn’t worry about low intermittent setting just have them on full chat and forget about overheating!! Cheers Roger

Chris Kennedy · Oct 22, 2018

Thanks, I appreciate the reply and advice.

/s/ Chris

Mark IV · Oct 22, 2018

Chris,

I have not had a SPF GT that cycled that quickly. Usually 60 seconds "on" or more. I suspect you may have a relay problem.

Chris Kennedy · Oct 22, 2018

Mark IV said:
Chris,

I have not had a SPF GT that cycled that quickly. Usually 60 seconds "on" or more. I suspect you may have a relay problem.

Thanks---I will look into it!

/s/ Chris

Silver66fb · Oct 23, 2018

Chris,
Also be sure your coolant system is burped - no air trapped. You can search these forums for more about that issue. That might cause some faster up/down cycles on temperature. I used a vacuum fill system to make sure to draw in the coolant without air being trapped. My system doesn't cycle as fast as you describe.

Tim

Coolant Fan Cycling

Chris Kennedy

Chris Kennedy

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Chris Kennedy

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