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MG MGF Technical - Coolant queries

The coolant in my mgf is a green / yellowish colour which I believe
Is Unipart super plus 3 which contains ethylene glycol which is
Unavailable now,I have seen Comma x stream G48 which also
Contains ethylene glycol which is blue in colour,my question is
would it mix ok with existing just for topping up purposes not
That I need to top up very much ,it would be nice to hear the
thoughts of you guys out there.

Cheers Peter.
p le rossignol

Hi Peter,
Just until someone with far more know-how comes along, I'll have a go at helping.
In general, people seem to empty, flush and then refill with OAT coolant....the pinkish stuff, as it has properties that weren't available when the early ethylene coolant was about.
From what I've seen, everyone says, it's your car and your choice over which coolant to use, BUT don't mix them.
Empty-Flush-Refill with your coolant choice.

We've a '96 vvc and are still trying to find OAT down in SW France, at the moment.

Hi Graham
Thanks for your input which makes sense the only trouble being
Finding a garage that knows about mgfs, we all know about
Airlocks in the system leading to the dreaded hgf.
There was an mg garage here but it no longer exists.

p le rossignol

Same problem here Peter.
You find a lot who think they know about the F issues, but their info usually ends with HGFs.
Have you tried online ordering ?


As Graham has said mixing OAT and non OAT coolants is not advised, the 2 are incompatible and will form a sludge in the cooling system.

OAT (pink coolant) is the current norm for most modern cars and should be widely available. Draining and refilling the cooling system isn't difficult, the easiest way is to disconnect the rubber pipes at the rear of the metal pipes that run under the floor of the car. This will also give you the opportunity to inspect the metal pipes which are prone to corrosion and if need be replace them with stainless versions which are relatively cheap and readily available.

Having drained the system you can flush the system by a number of methods, you could connect a hose to one of the disconnected pipes and flush until only clean water exits or you could reconnect the hoses and put the hose in the coolant tank and remove the bleed screw from the radiator or a combination of both. Once flushed and drained again, reconnect any disconnected hoses.

To fill the system I normally prepare a sufficient quantity of coolant, (I buy mine in concentrate form and mix with water but you can get it pre-mixed), fill the coolant tank and bleed the air from the radiator bleed valve. Once air stops coming from the radiator bleed valve replace the valve and bleed the heater bleed valve (youíll need to remove the black plastic cover just below the windscreen to get to this one) and then the bleed screw on the coolant pipe in the engine bay (youíll need to remove the engine cover to get at this one).

I would suggest you go round the bleed valves a couple of times to ensure no more air is present. You also need to ensure the heater is set to max heat while doing the above.

Having done the above, ensuring the coolant level didn't drop to low in the expansion tank while doing this, start the engine and let it idle until the radiator fan cuts in, this can take about 20 minutes depending on the air temp. The temperature gauge should rise to about halfway and the fan should cut in for a minute or two then stop, leave the engine running and after a short period the fans should start again and then stop. Check the heater is blowing hot air and if you havenít replaced the black plastic cover at the front you can feel the rubber coolant pipes which should both be hot (one hotter than the other).

This should now be complete, you can however if you wish wait until the system has cooled and re-check the bleed screws, you will need to remove the coolant tank cap to get water to come out of the engine bay bleed screw.

I've used this method a number of time times without issue and any reasonable mechanic should be able to do this but the critical factors are:- ensure heater is set to max and bleed all three points.

R.A Davis

Nice one Bob, you've explained the proceedure far better than I could've.

Hi Bob and Graham
Graham has explained the procedure very well but I think I lack
the ability and confidence to do this,I will have to find somebody
With a bit more mechanical knowledge than me,it's nice to get
feedback from you, thanks.
p le rossignol

Another tip is to replace the radiator plastic bleed screw with a Mike Satur version. I changed to OAT a long time ago after running the car for an hour with fresh water as a flush. I changed coolant again after five years and again after ten years. So far, so good.
Brian Highe

This thread was discussed between 07/01/2017 and 01/04/2017

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