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MG MGF Technical - Thermostat housing

I've got an 02 135. How easy/difficult is it to remove the thermostat? Can it be done from underneath, or do you have to remove the inlet manifold, or both?
Is it also worth renewing the water pump when changing a cam belt, and also the cam bolts/tensioner? It's only 3+ years, and 25K.
Jerry Herbert

you can do the thermostat thru the engine grill.
but buy yourself a decent 8mm ratchet spanner

the thermostat is held in with three 8mm headed bolts, and they don't stick (which is nice), _but_ the houseing pushes into a metal pipe which runs around the engine, it is held onto the block by a number of 8mm headed bolts (3?) so you need to losten these too.

Take care not to pinch the thermostat gasket when you put the bolts back in.

From above you will have to do this all by feel, and you cannot fit a ratchet in. from below you may be able to see some of the bolts, but at least one will be out of sight.

Re ther water pump. It's not a standard replacement item, but are you sure that the whine is from the tensioner and not the pump? In you case I would replace it.
Will Munns

Thanks. Not knowingly got a problem!!!
Just that when the weather breaks next year, I'm taking the car off the road for a bit whilst I try and fit my MG-R 25 diesel laminova oil/water intercooler.
By then I thought it might be wise to change the cam belt, tensioner, coolant etc as coming up then to 4 years old. Just getting my ducks lined up.
Jerry Herbert

From my, and several others, experience it is worth replacing the tensioner at the same time as the cam belt. The cost of failure far outweighs the additional cost, should the tensioner fail. I was quoted a *minimum* of 1500 for repair by the dealer, or 3k+ plus fitting for a new engine.


Jerry, I've never attempted this job myself, but I suspect that with the alloy inlet plenum, access is going to be somewhat tricky even with the benefit of ratchet spanners as Will suggests.

Best approach is probably to remove the inlet plenum, unfortunately.
Rob Bell

Nah, the alloy inlet manifold is not a problem, the problem is that you only get about 2mm of movement in the spanner. a ratchet spanner will do the job slowly, but a hell of a lot fater than taking the inlet manifold off.

trust your fingers, there are no other nuts to be mistaken by.
Will Munns

Fair enough! :o)
Rob Bell

Thanks for that guys, got the 8mm spanner now!
Looks easier if you move the header tank and dipstick out of the way.
Another thing struck me tonight, the thermostat on the MG-R diesel laminova is set at 82*C, and the K series smaller engines seem to run at 88*C.
Question for the experts, is an 82*C thermostat going to be OK in a remote thermostst? Or am I imagining a problem? Just need to know best opinion, as the thermostat in the laminova does not look as if it is available in a range of temperatures.
Jerry Herbert

82C thermostats are usually fine on a K - in fact, there is quite a movement amongst many, especially in the Lotus fraternity, towards fitting 82C thermostats in preference to 88C.

Personally, I'd keep to 88 - but you'll certainly do no harm in the short term with an 82.
Rob Bell

I use an 82 thermostat with no probs at all.
Blue Pocket Rocket

A "flexidrive" (screwdriver handle with long flexible extension suitable for small 8mm socket) is IMO needed to stay cool and keep a decent language during the operation ! 82 deg. thermostat keeps things a bit cooler, does not alter temp gauge thou. Sits at the same "one notch below" probably at all temps between lukewarm and meltdown...
This weekend I mounted a digital "steak thermometer"in an attractive housing on the panel as a more accurate temp check. Gives fast uppdates of the temp readings of the coolant AND a warning signal at a pre-set temperature.In my case set at 92 deg (well done /slightly red inner core ;O)) / Carl.

Where does the fan come on?
Will Munns

Standard is 102 deg. ON / 96 deg. OFF. Can easily be adjusted (lowered) to suit cooling system changes.
With external thermostat housing at the front with 82 deg. thermostat my fan is set at approx. 98 ON /92 OFF.
Farnell /ELFA has excellent quality glass termistors in small step and wide ranges that fits inside the original housing.A blob of white silicone "grease" between the termistor and sensor body assures fast thermal tracking. / Carl.

I thought it was up there - so your light comes on when-ever you slow down?
Will Munns

> and keep a decent language during the operation.

Fully agreement, and see for someone with a box of plaster !
Affiliated works position (MPI) (you feel like a _m midwife_)

This thread was discussed between 01/12/2005 and 06/12/2005

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