Overheat but with fans on

[RayD]

A picture of each would be handy... It’d be interesting to see if they differ in design. For instance...The type with a float in the bleed hole was meant for horizontal fitting.

Ray

Edit...See Failed Parts Summary

[GeoffSmith]

I've long suspected that aftermarket thermostats aren't up to the quality standards of the originals - why do the latter work for 15 years and the former seem to fail after no time at all? I even decided to buy a Lotus one as a spare.

Don't forget to try and capture this for your failure history log Ray.

[dermotbell]

That's where I was going to get mine...............hmmmmmmmmmm.......need different supplier

[L.G.]

You can buy a Beck Arnley one from Rockauto. I have one, used it for over a year now, no problems. (so far )

L.G.

[JimF]

I arrived back in UK after 12 days away and had an uneventful journey home until i stopped at a gate.

It was 2am and I was pretty tired so didn't notice the temp gauge on the 25 min drive home. What i did notice was the fans were going, which was unusual as the drive home is open roads. The temp gauge was nearing 3/4.

My first thought is that it was the thermostat seized in the shut position but why then were the fans on. Surely if the thermostat was seized no water would get to the sensor as it is on the other side of the circuit.

When I stopped (eng off) the fans kept going and after 2-3 mins cooled the temp. Is it possible the thermostat opened at a higher temp to allow the water to circulate.

I am planning to replace the thermostat, and am now searching the site for alternatives to OEM.

I had exactly the same thing. Again the car was low on coolant when I finally checked. We had a long journey back from the Le Mans classic arriving at night in bad weather and couldn't get the screen inside to clear with demisters on. Turned out that the demisters seem to be blowing water vapour, so probably a fine leak in the matrix or somewhere in the heater. There is a damp feel to the carpets at the side / front of the tunnel after heater use. The car runs fine with no coolant loss with the heater off.

Problem is how do I get at he heater matrix to check it (and the hose connections)? Had a quick look but it seems to be deeply buried behind the dash somewhere.

[DeeAitch]

A picture of each would be handy... It’d be interesting to see if they differ in design.

Some pics here
The Halfrauds one has a notch in rather than a bleed hole. Can't imagine it would allow much flow tho'
Also makes it hard to get any trapped air out of the head

I'm intrigued how the fans would stay on with the engine off
As Sy has pointed out this condition should activate the electric pump