Cooling fan not kicking-in

[Paul Cyclops]

I only run my Mk 1b every 10-14 days this time of year, just a handful of miles to pump the fluids round, charge the battery and work the brakes.

Always starts on the button, settles quickly and runs impeccably until this afternoon. A few minutes into my short journey in central London, I was aware that the heater was still blowing cool air but the temperature gauge was creeping beyond the normal mark. After a further mile or so, the gauge was on the cusp of the red so I pulled over and topped-up the coolant (always carry some red stuff and a litre of water with me).

The rad fan hadn't engaged at all though the 20a fuse that I presume governs the fan was intact. The car cooled after 10-15 minutes and I gingerly managed to make my way safely home without boiling-over although there was some light steaming.

The water pump hasn't failed so where's the first place to look - is it the thermostat?

Cheers
Paul

[LimeyMk1]

Thermostat stuck closed would be my first port of call, however this doesn't explain why you lost coolant. You may have sprung a leak.

How much coolant did you have to put back in?

[Paul Cyclops]

About a pint I suppose - it didn't dip below the min in the header tank and I vented the steam. I was lucky I could find somewehere to pull over and that I noticed straight away.

I'll change the thermostat shortly. Cheers.

[scomr2]

The passenger compartment heater is on a different circuit to the rad so the fact that this wasn't getting hot suggests there is more wrong than a stuck thermostat.

[Paul Cyclops]

The passenger compartment heater is on a different circuit to the rad so the fact that this wasn't getting hot suggests there is more wrong than a stuck thermostat.

After looking through the BGB through tear-stained eyes, I'm going to check the temperature sensors connectivity. If I can't fix it by jiggling things about, I'll have to think about trailering it away and paying through the nose. I don't have a warm garage and I don't fancy crawling about in the damp dirt in a communal car-park with my incomplete collection of basic spanners.

The only thing I didn't perhaps stress was the rapidity with which things cooled down once I stopped the engine. Don't know if that's significant but I thought it unusual.