Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Running cool

Hello again
Driving down from a Trip to Revolutions in Perth (top guys by the way)I was keeping an eye on the temperature gauge which was only reading around 70 and the heater was only blowing luke warm air.
All my other and previous cars tend to run at 90/100
The car does have a new aluminium radiator fitted.
Any thoughts or comments?

I have an ali rad the heater is fine. Was the heater fully open? Were all 4 vents open on the heater box.You don't say what car you have I know some +4 I think duratchs had thermostat issues.

From your previous post regarding your diff, it seems you have a 2009 4/4, but don’t know your experience with Morgans.
As John says, check that all 4 heater louvres have been opened (by hand) Also note that the heater knob and mechanism can be very stiff and full output may only be achieved if you rotate it to at least 4 stops or even 5. Morgans tend to run a little cooler with an Ali rad anyway, but even at an indicated 70 or so, you should be feeling the heat.

It's ironic but some have found after an all aluminium larger capacity radiator upgrade that the car runs hotter in certain circumstances typically motorway cruising I believe. Reason is the thermostat which remains partially closed for longer to compensate for overcooling. It messes up the hysteresis but a thermostat change solves I understand.

The 3.7 Roadsters John V6 and I have seem to have very robust temperature control as no difference at all after rad upgrade other than fan coming on far less regularly.

To me it seems like your thermostat could be broken and it won't close anymore. Now the question is, what was the temperature before it stopped warming up properly? Can you remember if it was higher or lower with the aluminum radiator when driving faster than with the smaller OEM plastic radiator?
When I got my aluminum radiator new a few years ago, the engine temperature was always a bit too high when driving fast (which means about 160 km/h on the German Autobahn). This had always irritated me because the aluminum radiator cools more efficiently. After three years, the head gasket was broken due to the always slightly too high engine temperature. That's when I started to get interested in how the cooling circuit works on my 2014 4/4 with Ford Sigma engine. This is described in detail in this thread.

http://www.talkmorgan.com/ubbthread...the-cooling-water-temperature#Post713083

In short, because the thermostat on the Ford Sigma is not located in front of the radiator inlet but behind the radiator outlet in the engine block, the heat of the circulating coolant in the engine block is no longer sufficient to open it when necessary if the thermostat is cooled down too much from the outside.

But all this has nothing to do directly with your problem, but maybe indirectly. If a thermostat always runs too hot, it could be that it breaks down and no longer closes.

Yes, thermostat change helps, but it needs a second component. I had to partially cover the efficient aluminum radiator so that its effectiveness is about equal to the effectiveness of the weaker OEM radiator. Ford calculates the radiator efficiency quite accurately because it is part of the overall working system. I don't know if the Plus 4 has a comparable cooling system, but I assume so.

Interesting subject thermostats Heinz. Not all of a particular advertised temperature work the same. The opening range is equally important. I was given an "80°C" thermostat to cure overheating on a vintage marine diesel engine, replacing the previous 72°C one. It worked because the high temperature one actually started opening at 65°C. I suspect a new thermostat alone would cure your issue Heinz although admit a lot of thought, sourcing and experimentation would be needed. This would allow full use of your larger capacity radiator, possibly required in extreme circumstances.

Note after 2006 MMC fitted the same radiator to all Classics so the cooling system didn't have the benefit of custom tuning of system that Ford would have made to each of its cars.

I would check the obvious first is there fluid in the expansion tank., any chance of air lock somewhere (try parking on a steep hill & opening the heater up).

That's certainly worth considering, Richard. Because as it is now I can not really take advantage of the benefit of the larger radiator, for example, in a traffic jam in the hot summer or I have to change the area of the cover of the radiator more often, so less in summer, more in autumn and winter.
Your thought seems very conclusive to me. Already on the standard Ford, yes, the thermostat is an 82 degree (from memory) type so the engine reaches about 88 to 90 degrees. On a conventional cooling circuit with a thermostat before the radiator intake, it would be an 89 degree thermostat to keep the engine at 89 degrees.
But in my case, without the radiator cover I might have to install a type with a characteristic that might open as early as 75 degrees (as an example) but then also stay closed until, say, 82 degrees. And I agree, all possible Ford engines, from the 1.6 to the 3.0 had the same radiator in the Morgan which is not the Ford philosophy.

Maybe for fun I'll install a 77 degree type or similar if I can find a thermostat that fits the Ford mechanically. Another difference to the conventional circuit is that when the thermostat opens, the cold water flows through the direction of travel and not the hot water...and that the thermostat must react to the mixing ratios of the temperatures it feels from both sides....quasi a temperature mixing sum must move it to open

|Completely different engines, so may be irrelevant but on my Mog with a Xflow I had the same issue - replaced the 82 degree thermostat with a 92 degree and now getting decent heat.

Had a similar problem with the Vx Corsa and that was down to an airlock in the matrix - the in pipe was hot, but not the out pipe. I spent some time squeezing hoses and now gone. On the Mog I fitted a airbleed into the exit hose, wish Vx had done the same.