Talk Morgan Forums Morgan Sports Cars Morgan Aero 8, 2012< Plus 8, SuperSports, Coupe & Aeromax Running temperature

Hi guys, what running temps do you see on your bmw v8 powered cars?

Well. the needle is normally vertical-ish.

The LCD readout varies between 95-100 normally, give or take a degree or two, depending on the temp of engine and air, and whether the aux radiator has opened.

What temps are you seeing?

I get two different readings from the cars with one clear change - the air-con

The S2 with the 4.4 (more room around the engine?) seems to sit around 92 with the air-con on and around 96 with it off in main road driving.
The Coupe runs warmer at around 96-7 air-con off and 102 with air-con on in general driving.

I guess the air-con causes the fans to switch on and means the main rad is cooler?
They have been pretty consistent on these temps for 30k each.

What are you seeing on your - I assume it is the famous flip paint car in the picture in which case it is an S4 - 4.8 like the Coupe?

p.s. I have not thought to use the digital gauge but I do monitor the temp gauge having had a fan fail on the S2 in the past. Given traffic was free and I was just up the M4 from the dealer I was able set the heating to max and just gently tickle it up the motorway without any nasties.

I am seeing it around the 104 mark, that was without the air con on, it does seem to fluctuate a bit though but the max it has hit is 106

This is quite normal in winter - there was some previous discussions a few years ago. My S1 runs at 104 and its all to do with BMW design logic !

My 4.8 runs cool in hot weather and quite hot in cold weather.

It's around 90 when very hot (I had a month in Provence this year which was very hot) and around 100 when it's cold.

My S4 does the same too, a bit disconcerting at first.

Too much hysteresis in the coolant temperature control. There have been similar issues when more efficient after market aluminium radiators are fitted, actually increasing engine temp under certain motorway conditions. Cure I believe was an alternate thermostat.

Note not all thermostats of same quoted temperature are equal. I had an overheating issue with a boat diesel engine cured by a higher temp thermostat because it started opening 14°C below its listed temp.

If it gets too hot there is a warning light on the dash which coms on - only ever experienced that when I was losing coolant due to a split radiator hose.

Indeed. I tend to treat the guage as a vague indication of warmth, and the LCD as perhaps a more accurate read of whether the engine's 'ready to do some work', or perhaps 'hotter than I might expect'

... there's also the auxiliary radiator in play here, which does sometimes produce counter- intuitive 'runs cooler on a hot day'

Will