Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGF Technical - Electrical waterpump

Hi all,

To prevent HGF problems caused by the thermostat, I am thinking of replacing the thermostat and waterpump by an electrical waterpump. Has anyone have any exprience using electrical pumps. The pump will stand (nearly) still when the coolant is cold. When the water is heating up, the pump will start operating, increasing speed related to the coolant temperature.

Can anybody help me with determing the pump capacity and the 'circuit' of the coolant at which it will travel through the system.

Thank you

A.P. van Wijngaarden

I don't think you have to go that far. The thermostat is in the wrong location so you could either try the QED or mgtf solution, either one will be a lot simpler to install (see Rob Bell's site for details).
Blue Pocket Rocket

Sounds like a good idea, there are pumps/kits on the market that can be used, Craig Davies I think, have seen them in Demon Tweakes.

Is there any chance you mean Davies Craig Mike :o)

About 70 quid and it just needs a simple timer. Rob and Will will be along later....

tim woolcott

Thank you all for these replies.

I have looked into the Davies Craig electric waterpump and it seems a very nice solution (only a bit expensive...).

I have thought about the remote thermostat solution using a QED thermostat. I have found an article on using this thermostat on Dieter's site
This article describes the use of the remote thermostat placed near the radiator. I don't really understand the benefits of this solution. The original thermostat (although holed) is still being used and will probably still close when cold water from the radiator is received.

Isn't it possible to completely remove the original thermostat and place the remote thermostat near the coolant outlet of the engine.

A.P. van Wijngaarden

Alex, the Davis Craig water pump has an inadequate flow rate to completely replace the standard mechanical water pump, whose output is truely prodigious. It's a non-starter I am afraid - and it is interesting to note that if you do a search on the internet to see cases where this has been done, the impression that this mod is worth while is pretty negative.

What I've got is something a little different to what you had planned (which is what Tim has mentioned) - a simple timer driven water pump that circulates coolant around the head once the engine has been switched off. It isn't a HGF cure though.

The remote thermostat modification is probably worth persuing. Two or three options there. One is the QED remote thermostat, another is a similar bit of kit from Both are for the Elise, but the kits ought to be easily adapted for the MGF. Chat to Thierry, as he's taken this path already.
The other choice is to take the OEM route, using the MG Rover "remote thermostat". It's fitted to all 2004 model year and later MGTFs, and can be readily be retro-fitted to the MGF. Costings are difficult to come by, partly because the parts availability is not great, even now 18months on from the system's release.

A bit more reading here:
Rob Bell


Have a look at QED's website
or Rob Bells site Basically you remove the thermostat from the housing and re-assemble using the large washer supplied in the QED kit. The QED thermostat housing (new thermostat is already fitted) is connected into the top hose (the outlet side of the engine) and means that the flow of coolant is being controlled in response to engine temperature.
Blue Pocket Rocket


Davies Graig produces 2 types of pumps.
A booster pump producing 13.3L/min, which is described in the link you gave me

A second model is probably more for use as a standalone. It produces 20 to 80L/min. The pump can be speed regulated. When the engine heats up the pump can be made pump harder.

I do not know exactly I can expect from this pump, but it seems to be better performing than the booster pump. It not cheap though!!

The remote thermostat seems like a nice option. For now I shall look into this option first.
A.P. van Wijngaarden

That's correct Alex, but the mechanical water pump has a capacity of over 200l/min at 2000rpm - the larger version of the pump can't muster even 50% of this at peak load. Add to that a somewhat limited service life, the case for replacing the mechanical water pump with a Davis Craig EWP simply doesn't stack up.

There is good reason why car manufacturers haven't taken this route yet - although I am sure that many are taking an interest in developments, as your basic premise is sound.

Therefore, I'd definitely go for the remote thermostat - be that the OEM MG Rover item, or one of the aftermarket alternatives.
Rob Bell

I have the OEM Rover item which is fitted to the later TF fitted to my 97 1.8i and have noticed one big differece which is it takes much longer to warm up, I assuem due to the fact water is constantly flowing. This is not a huge problem and if it aids the engine in life then I am not complaining.

I had the thermostate fitted as I wanted all the pipes in the engine bay replaced due to the age of the car and reports of pipes failing so did the upgrade at its service.

Tom Randell

This thread was discussed between 22/03/2005 and 24/03/2005

MG MGF Technical index

This thread is from the archive. The Live MG MGF Technical BBS is active now.