Talk Morgan Forums Morgan Sports Cars Morgan Aero 8, 2012< Plus 8, SuperSports, Coupe & Aeromax Coolant Temperature Observation and Question

Clearly an intentional peculiarity!

I don't think it is a sticky thermostat as the car heats up quickly, it just has a winter and summer mode....!

I believe the radiators are stacked closely. As soon as you turn on the Air/Con the fan kicks in to provide a steady flow. I figure this is also running over the engine radiator so it keeps it lower than the main fan kick point. I suspect the main engine fan is programmed to come in at 103ish.

The S2 and especially the Coupe seem to do the same.

Wish my old +8 would do that, better heater output.

Not an Aero car but......
Went to Williams Saturday...Rover Plus8.
Coolant gauge showed just touching 80C all the way.
In summer this would have been 85C ish.
Colder air giving more cooling through the rad.
Yes, a simpler set up than an Aero car but shows the basic (Ye canna change the laws of physics, Captain).
In summer my car runs warmer and fan kicks in when in slow traffic or just after stopping after a good run (heat soak causing water round fan sensor getting hotter). No overheating issues at all.
Under bonnet temperatures are correspondingly higher too. Tests in both summer and winter show significant differences resulting in warmer air being sucked into the engine.
I would like a bit more air hitting the rad in summer so may look at diverting some up there with the ability to block it in cold spells in winter. Also cooler air feeding to the air intake.
Years ago I had a Maxi that had an adjustable louvre to block part of the rad in winter/cold running...quite neat on such a basic car!
OK, the BMW system for Aeros may have more sensors for the A/C and ecu map requirements but may not fully compensate for lower air temps or deliberately manage them differently? Is the higher engine coolant temp due to the ecu causing different combustion to manage emissions due to colder air?
I also remember one car that I once put the heater on in summer as I had a coolant loss and needed extra heat extraction until I could pull in safely.

Its a real puzzle this one Peter. I cant think of any reason why it should be programmed to do what you say it does, but I have little doubt that it is programmed rather than any sort of fault.

Might be worth having a word with your local BMW dealer since if as I guess this is a design feature of the engine, it will also happen on their cars.

I still think its to keep the water temp up to keep the heater working in the cold air.

Do people really drive looking at the gauges all the time? I swear blind that if we get more gauges we just worry about me stuff, conversely take them away and you never worry about it.

I find corners and stray wildlife far more of an on the road distraction.

Mine does exactly the same, new to me in spring this year so a bit more aware of things in those early drives.

Hi Peter,
My Aero Plus 8 does the same. Last winter the engine ran at 100 degrees gradually dropping away as the weather warmed. All summer the engine has been running at 90 deg but as soon as the temperature dropped again, it climbed back up to 100 deg. I kept a close eye on the engine temp while I was trying out Cain's prototype bump plate for him.

Tested over a good few thousand miles, the plate makes no difference to the engine temperature as far as we could tell.

I wonder if this is a phenomenom that occurs on some everyday cars as well, but we can no longer observe it. I remember reading a while back that on a lot of modern tin-tops the temperature gauge stays rock steady in the middle of the gauge providing the temp is above a low setting and below a high setting. This to stop owners worrying about temp fluctuation.

Cheers