290S Water Temp

[Daniel-vwbsa]

Only recently got the car so please be gentle. I'm after some advice on what would be perceived as a normal water temperature on a steady 60mph run. My car tends to temperature cycle which to my mind does not seem correct. The temperature will build upto the line on the dial above the 90 not sure if this relates to 90 or higher. The fans then kick in and the temp drops back down nicely, this cycle constantly repeats itself over a 5-6 minute period
I was expecting that the car could maintain a steady temperature without the need for fans at a constant 60mph. How does everyone elses car perform.

The cooling system is only a few years old, new rad, pipes, pressure cap on the swirl pot. I have also bled the system to death.

I was wondering if maybe the fan is coming on to early and if it waited a bit longer it might reach a steady temperature. I'm also concerned that if the fan is required to maintain temperature that if it fails disaster will strike.

Yours confused, Dan

[Daniel-vwbsa]

Yes, that could make sense. Do you know if the fan is controlled via the ECU or by a simple temperature switch?

[Daniel-vwbsa]

I'll have a bit more of a poke around and see what I can find. The cars not overheating I was just expecting that on a constant steady run the airflow through the radiator would be enough to maintain temperature.
Could it be that actually the fans not coming on at all and that the thermostat is opening and closing causing the temp fluctuations?

The car is actually an S1.5. I have the 2.9 V6 and a mix and match of S1 and S2 parts. Good old TVR not wanting to waste a single part..

[Daniel-vwbsa]

yknot said:

Apologies if I misunderstood but how can you hear the fan coming on/off at 60mph? I'm sure I couldn't hear mine over the noise of the exhaust, etc!!

You are right I cannot confirm the fan is coming on that is just an assumption I'm making. I will look into getting a lamp installed to check this. I'm quite probably worrying about nothing.
When stationary the fan tends to come on at around the 90 line and this is about what the temp gets to on the road before coming back down again hence the assumption.

It does seem that the thermostat opening temperature and fan turn on temperature are rather close together, I would have thought there would be a bigger deadband between them to allow the thermostat to do its job without the fan potentially interfering straight away
Thanks for all your advice it gives me a few thing to look at and try.

Edited by Daniel-vwbsa on Friday 19th May 16:17

[Daniel-vwbsa]

yknot said:

Apologies if I misunderstood but how can you hear the fan coming on/off at 60mph? I'm sure I couldn't hear mine over the noise of the exhaust, etc!!

You are right I cannot confirm the fan is coming on that is just an assumption I'm making. I will look into getting a lamp installed to check this. I'm quite probably worrying about nothing.
When stationary the fan tends to come on at around the 90 line and this is about what the temp gets to on the road before coming back down again hence the assumption.

It does seem that the thermostat opening temperature and fan turn on temperature are rather close together, I would have thought there would be a bigger deadband between them to allow the thermostat to do its job without the fan potentially interfering straight away
Thanks for all your advice it gives me a few thing to look at and try.

Edited by Daniel-vwbsa on Friday 19th May 16:51