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MG MGF Technical - QED Remote thermastate - Problem

Just fitted QED Rover remote Stat.

I started the car this morning. I got her to run hot in the garage with front rad fans working and heater on. No problem. Temp gauge rock steady. Clearly thermostat was fully open.

As soon as I turned heater off the water in the expansion tank started to bubble like mad and temp started to rise. I turned off car to cool down. Why should turning the heater off cause this to happen remembering the thermostat should remain open when I turned the heater off? I have driven 250 miles with the remote stat fitted and heater on. Temp steady all the way.

Has anyone fitted the QED Remote Stat on the MGF and if so please confirm how plumbed in especially the T junction?

Old stat has been removed.

Many thanks.

Julian

Julian

Julian,

Its as if the system is cooling via the small heater rad.

Is your front radiator ok ? and the pipes to the rad ?

Its a strange one alright, but from what you describe its just as if thats happening. With the heater on the coolant should circulate through rad and heater, and as you say thermostat is open as engine hot so should go through rad.

But as you say closing off the heater circuit causes temperature to rise.

Brian
Brian

I've heard of someone else having a problem with the QED remote thermostat before - but that was due to a garage fitting it back to front! Perhaps the thermostat is faulty, as you suggest. Where have you fitted it - and have you removed the original thermstat and replaced it with a restrictor ring PEL000040A?

See http://www.mgfcar.de/epc/2630.htm
Rob Bell

Rad is fine - fans come on as hot water passes through radiator. Bled correctly (by Make S. and since I have come home by me)and re-bled. Mike did the original fitting.

Ideally I need someone who has a QED remote fitted to input.

Thermostat replaced. Fitted at bottom of S bend output pipe from Engine which goes ultimately to top radiator hose. Original thermostat removed by Mike.
Julian

Is the radiator getting warm Julian? The easiest test of this is to remove the bulk head trim and feel for the temperature of the radiator feed and return pipes as they run under the windscreen washer bottle. If both are running cold, then hot coolant is not reaching the radiator suggesting a blockage of flow.
Rob Bell

the stat which controls the radiator fan is in the alloy elbow attached to the head, thus it is not nesecerally a slam dunk that the radiator is getting flow (the fact that the rad fan switches off points that way though)
Will Munns

The hose to the radiator gets hot and the one from the radiator is cold. Plus radiator fan kick in. I have no idea why the temp moves around so much!
Julian

Stone cold? That's very odd... this does sound like a flow restriction; perhaps air lock in the rad?

Regarding the removal of the original thermostat, just check with Mike that he fitted the flow regulator (I am confident that he has, but it is worth checking!)
Rob Bell

I'll check whether stone cold tomorrow. Certainly cold engine end (and the hot pipe VERY HOT!). I'll check radiator end next time.

Water gushes out of the rad (and hot) so I doubt an airlock but worth rechecking.
Julian

I would have thought if the spacer ring had not been fitted the thermostat housing would leak. I think Julian you have either still got an airlock or there is a problem with the jiggle valve. According to the workshop manual the jiggle valve prevents pressure build-up in the expansion tank by regulating the amount of returning coolant, but in your case it doesn't seem to be regulating enough!
Blue Pocket Rocket

Got it working (at least in my garage). Left engine on for 20 minutes to get hot. Left heater off first then turned back on - temp did drop 2 notches and then came back up(Perhaps once on road it will just stay normal as engine will be generating constant heat). Then turned heater off again and temp still remained steady.

I will road test it this weekend and see what happens.
Julian

This thread was discussed between 23/06/2007 and 27/06/2007

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