Temp gauge and fans

[markcoopers]

So the good news is they work of sorts, but not sure what is going on.

Swirl pot is full, rad is full and expansion tank is half full. Car warms up and fans then come on with gauge saying 50. They stay on and it will climb to 70 but that is it. Driving the car the gauge will occasionally drop to 55 when booted like water is circulating and then climb to 70again. Fans never go off. This evening I let it idle and it did the same, up to 50 fans on then sit at 70 until reved. All hoses are hot and heater is blowing hot air. Swirl pot and rad is hot and lots of hot air from the fans, expansion is not that hot. I was able to open the expansion and it did gurgle a small bit of air but the level was the same, with a small noise from the swirl pot which I look to boiling water as now no pressure. Restarted and no change.

I assume otter switch issue may be the fans, and I know the gauge is a just that a gauge so this may be normal.....but thoughts?

No smoke or steam even after 30mins ideling

[Belle427]

If your fans cut in early I would expect to see similar results if they are having a cooling effect on the engine.
The gauges are just an indication, mine sits at about 80 cruising, climbs to 90 sat in traffic until the fans cut in.

[markcoopers]

begging to think i have a cooler operating otter switch.

The Low reading gauge is a common and known issue so that is OK, use it as a level indicator rather than an absolute reading

The fluctuations appear to be due to the sender location being in a blind ally and seeing air and water and thus showing fluctuations

The fans on all the time was while i was idling, it could simply be that the stat is keeping the temps correct, but that correct temp is above the lower limit for the otter switch. Perhaps in lower ambient temps it will switch off? How to check if they go off on the road when driven i am not sure as you can not hear them.

Tracking down the last owner might be a plan...

[Belle427]

You could wire some temporary indicator lamps back to the cockpit to tell you when the fans are on.

[Steve_D]

Get yourself RoverGauge and a lead.
The temp reading that will give is way more accurate.
At idle the fans should cycle off/on.

One of the boxes on our service sheet is a comparison between RoverGauge and the dash temp gauge.

Steve

[markcoopers]

thanks Steve,

I guess i am not really that worried about the level as there is no sign of it either over heating or running cool, it is more the fans on all the time once triggered. Still thinking it is a lower running otter switch, meaning that once up to temp and the stat is opening and closing to do so, the overall water temp is still above the otter switch lower limit. After all when cold the fans do not start with the engine, so the switch must at some point return to the open position meaning that it is not stuck just operating at a lower overall temp.

[magpies]

that's exactly what I've done on my S

now worked out that (using the gauge) fans come on when just into the red and torn off when back to the 90 deg white line

this is good as the Otter switch has 88deg C as it's off setting