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MG MGF Technical - Cooling fluid loss

I own a regular MGF built in 1998. I mainly drive her as a week end toy, carefully and no heavy foot at all. Only 35k done from new. Now lately I have noticed some green stuff on the floor at the middle of the engine and was unable to detect where it is leaking from. That never happens when the engine is hot but apparently there is a steady loss when the car is not used. I pour an extra pint of fluid every second week. The car has a cooling tank sensor so I am not very worried about. The question is...should I be worried?
Thanks and best wishes to all.
Edward Lyon

ANY coolant loss from an MGF should be dealt with immediately.
From your description, it sounds like a leak from a hose, water pump or head gasket.
Have it attended to ASAP.
DO NOT rely on a sensor, it may be too late then.

Tony Harrison

I agree that any coolant loss should be dealt with soon however is not easy to detect were the actual site is located. The same has happened to my F and twice have to spend some time at the garage having it fixed. But then it will happen again. I believe that the B&G water cooling sensor is reliable and if the worst happen -a sudden loss of cooling- it will let you know and you can stop the car ASAP.
Richard Holder

It actually is worth while trying to track down the likely area where the coolant is being lost, as it will give a clear indication as to the likely repair bill!

Coolant loss down the centre of the engine, to the rear suggests an inlet manifold leak (common on MPis with the original black coloured gasket - these always eventually fail - the later green type is much more robust).

A head gasket failure commonly fails to the right side of the car, at the front of the engine - usually above the alternator. Look near the exhaust manifold flange.

A leaking hose usually dumps coolant to the left side of the engine (often near the engine's outlet coolant stub where the temperature sensors are mounted).

As Richard says, it can sometimes be hard to track the leak down, but worthwhile, in that you can prepare yourself for the subsequent repair.
Rob Bell

>A head gasket failure commonly fails to the right side
>of the car, at the front of the engine - usually above
>the alternator. Look near the exhaust manifold flange.

and a water pump seal looks very simmiler on the floor, except the leak comes from under the cambelt cover.
Will Munns

Dont forget to have a look UNDER the car too along the welds opn the underfloor coolant pipes.

Oh and dont forget to check the stae of your radiator. Mine had more holes than fins before i got it changed. I could not believe the state it was in.

Unfortunatley you may have a leak which is slow enough or in a hot enough place that it gets evaporated before you can see it. Perhaps a pressure test would alert you to any holes anywhere
I Brown

Thank you all for your answers. A few extra questions. What is the inlet manifold and where in the engine it is located? Is itvisible? What would be the cause that the leaking occurs only when the engine is cold?
E. Lyon

'only leaking when cold' is an illusion i'm afarid

Inlet manifold is on the rear face of the engine, black plastic visiable thru the engine bay grill from the boot.

the original inlet manifold gasket rotted, i would be very surprised to find a car with a black gasket after all this time.
Will Munns

'only leaking when cold' is an illusion i'm afraid.
May be Will, however when I use the car -golf weekends mainly- I park and then five hours later return and always check for fluid loss before departure. Never a single drop on the pavement. But then next morning I always find definitive evidence of fluid loss on the garage floor. Can you explain Will?
Edward Lyon. UK.

I have just noticed a drop of green stuff leaking from the mid-engine, a bit to the right of the ignition coil. Do this suggests an inlet manifold leak?.
I really wanted to identify the colour of the gasket but did not know where to look at. Actually I believe it might be the original gasket as the engine has never been touched yet.
Edward Lyon

This is all good news, HGF tends to happen on the other side of the engine.

If the manifold gasket has not been changed it is the prime suspect, but also in that area are the thermostat and some coolant pipes and hoses.
Although I have heard of the pipes under the car rotting thru I have not heard of the same for the pipes on the engine, but it is sealed against the thermostat with an o-ring which might have died.

I would get it looked at asap, if the IMG has died then it might be being sucked into the cylinders when the engine is running, if it fails big style with the engine running it will fill a cylinder and the engine will hydrolock leading to knackered con-rod, liner and piston (cheaper to get a new engine time). This has been reported a number of times here.
Will Munns

I had the inlet manifold gasket go - It's obvious that it must have leaked continuously but it probably evaporated off the engine when it was hot and was actually more evident when the car had stood and the engine was cold as that was the only time I found water on the drive - I also found that if I took the expansion cap off after the car had been standing a while (overnight perhaps), then this made the leak become more evident (with the cap on, the system is sealed, removing it allows air into the tank and allows the water to flow) - I could then see the water track down the engine from under the manifold.
M Clayton

This thread was discussed between 17/06/2006 and 22/06/2006

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