Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Temperature

The other day, for the first time, I got caught in a traffic queue and the temperature gauge on my '92 plus 4 went from it's normal 80+ to 100+. I put on the heater and roasted. Today I had a run and then, once home, let the car idle until the temperature again went above 100. The fan cut in at about 105 but only briefly and then again only briefly. The differential on the "otter" switch seems very small. Would you say this is normal or do I need to change the switch.

If your gauge is anything like mine I would not worry too much as its unlikely to be accurate. For peace of mind i fitted an override switch so i can keep the temperature down in traffic, the dash light is more useful just to see if the fan is working. Otherwise it sounds sort of normal to me.

Bleed the coolant system incase you are getting airlock or consider changing the thermostat.

The censor that controls the temp in my car was changed to a Fiat one it kicks in about 82 and witches off about 106 if my memory serves me well.
Its a 4/4 1986 why not change yours.

Also, well worth considering removing the hoses and giving the radiator a good flush through.

Mine often goes to about 100°C in traffic. The high speed fan cuts in at about 93°C and cuts out when the temperature drops to 92°C. I think this is fairly normal for the modern lean-burn petrol engines. I found it a bit alarming after being accustomed to the relatively low running temperature of a turbo diesel but now I just keep an eye on it but don't let it worry me.

My Plus8 does the same.
In winter it runs at 80C. In summer at a85C+.
The higher ambient temp obviously has an effect.
The fan cuts in at about 95C+
When in traffic the temp tends to stay high and fan run more often.
It rarely happens in winter.
The car has a Morgan Al rad..
There are no apparent overheating issues so it doesn't worry me. Coolant never needs topping up.
The under bonnet temp does get quite high though. The air filter box gets to 50C and more.

I have taken off the top hose to measure the radiator inlet spigot. Car Builder Solutions sell an aluminium section for 32mm hose that has a bose to carry a fan sensor. By installing one I could read the temperature nearer the head. When I came to replace the coolant I couldn't get almost half of it back in. From where should the system be filled, the header tank which seems below the top hose or the radiator. After years of old cars I am at a loss.