Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Roadster S2 Cooling System

I'm intrigued by the cooling system on my new Roadster.

Much more complicated than my old Zetec 4/4 and some rather interesting pipework.

Don't know if anyone has a circuit diagram to save me the trouble of figuring it all out but I do have 1 specific question at this stage.

If you look closely at the rather poor photo you can see a pipe going directly to or from the oil filter cooler adapter (at the bottom of the picture) seemingly directly to or from the overflow tank in the cabin heater circuit.

Is it using the cabin heater matrix as an additional oil cooler circuit?

Now, I also notice that the tank gets much warmer than my old Zetec tank and it seems as though there might be some flow through the Roadster tank which seems strange.

Also, where is the pressure relief cap. The cap on the top of the tank appears to have some sort of mechanism inside it but that would vent to atmosphere I think if indeed it is some sort of pressure relief.

Very confusing to me at the moment although I'm sure I will figure it out sooner or later.

The system also seems to include a water cooled (or heated?) throttle body.

BTW currently runs Evans Waterless and if the gauge is correct the temperature is only running at about 85 degrees.

Call me Monday
I’ll talk you through it

And get rid of the Evans....

Thanks Simon, will do.

I am not sure how close to the S1 the S2 is but this might help.
http://www.talkmorgan.com/ubbthreads.php/galleries/39519

And when you call Simon, place an order for stainless steel T pieces to replace the fragile plastic ones in the cooling system. IIRC, there are 2 on a Roadster - the one in the picture and one other that is more fragile,

Agreed I replaced mine courtesy of Simon plus on the S1 at least the plastic T piece of the engine breather with a brass one off ebay

I thought the Plus 8 cooling system was complex, until I looked at the C63.

There are multiple thermostats, well, electrically operated valves that manage water flow so that the engine heats up as fast as possible, but there are if/But logic gates depending on ambient temperature, car heater heating demand, oil temperature and transmission oil temperature.
There are multiple electrical water pumps, plus three heat exchangers that transfer heat between oil, water and air. There is a separate cooling system for the Turbos with a seperate header tank, plus I understand a water/water heat exchanger to transfer heat from the turbo cooling circuit to the engine cooling circuit. There are then an oil cooler and a heat exchanger to keep the inlet air temperature within precisely controlled values.

All very clever, but probably not really repairable by the DIY mechanic. I had a failed radiator and it was replaced under warranty. The radiator cost less than £300, but there was £600 labour. To get at the radiator all the front part of the car had to be removed, then the cooling system had to be drained and to refill the Mercedes service computer has to be connected to the OBD port so it can manage all the valves and pumps to ensure there are no airlocks and so on.

Amazing, but I doubt very much that these cars will ever be "collectable" in the way a "Trad" or Aero Morgan is/was.

Thanks for the input guys. And to DW for the diagram. Hope he doesn't have copyright or we're all in trouble.

That diagram looks very similar to what I have although the blank connector on the header tank is the return from the throttle body on mine.

The TB takes its feed from another nylon Tee of the heater circuit.

Also need to understand the bypass circuit which isn't really shown on this diagram.

Short update.

Had my chat with Simon on Monday and he put me straight on a few things. Thanks Simon.

DW's diagram of the S1 is pretty much the same as my S2 other than the hose which goes to the throttle body on mine.

A lot more hoses than on my old 4/4 and some of them damn near impossible to get at without stripping other things off first. Including the thermostat.

The big question now it whether or not to persevere with the Evans Waterless in the system or change it back to regular antifreeze.

I'm tempted to run it through the summer at least to see how it handles the hotter weather.

Incidentally, I checked the coolant temperature compared to the in car gauge with my new OBD reader and when the gauge was reading about 82 (ish) the OBD readout was 90 degrees. I'm happy with that as I felt 82 was a bit low for a modern engine. BTW that was after a hard blast (Italian tune up) with nice dark colouration on the exhaust pipes.