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MG MGF Technical - Interesting water loss

I checked the water level in my 1.8I on sunday with the engine cold, coolant was down to the lower mark and I topped it up to the upper one, just below the seam in the tank. I did not drive the car on sunday, but after backing the car out of ther garage on Monday a small pool of coolant was left on the garage floor under the overflow pipe position. I was very careful putting the coolant in, using a funnel and did not spill any.......any Ideas folks?
Phil Stafford

Have you checked the seals/clips on the coolant pipes, if your coolant was down to the minimum mark you must have been losing it at some point, mine is leaking at the heater connector join at the back of the engine.

I have been informed this is common, Mike Satur does an aluminim connector and stainless clips which I will be purchasing to fix the problem, about £26 and the cost of a coolant change afterwards.

If as you say you were careful whne topping up, I suspect a leak will be apparent put the car up on ramps at the rear and get out a torch to inspect the pipes and clips, if you have a leak you should be able to clearly see staining.
Chris Catchpole

I don't think that this is the reason. The car was recently serviced and had a number of the clamps replaced along with a coolant change and a new cap. I had not experienced a loss of coolant prior to this (other than due to a bad cap or overfilling the header tank, both of which have happened in the past) and have not seen any evidence since. This is the first coolant top-up (about 1 cup full) in about 6 months. If the fittings were leaking it should happen regardless of the level of the header tank as there is always water in the block and hoses. I have had small amounts of overflow in the same location in the past but usually on a hot days (35 to 40 deg C) when parked in the garage (40 to 50 deg C) after driving in heavy traffic. Waht amazed me this time was the same small puddle on the floor from a cold engine. I was wondering if there was some sort of pressure pulse from the waterpump on start up that might push a small amount of water out the overflow
Phil Stafford

Have you checked above the alternator at the corner of the block, classic place for HGF. If you have recently had coolant change and the system was not bled properly, hot spots can occur and the gasket eventually gives up. Water comes out under pressure, on start up and drips over the alternator onto the floor, if this is the cause again you should see tell tale signs of staining.
Chris Catchpole

I'll check this although I suspect it won't be the cause as I replaced the HG about 6 months ago with new gasket, dowells, cam seals, head skim, coolant etc.etc. done by a reputable MG workshop who properly bled the system. Your comment about water pressure at startup might be the key to a small leak somewhere else though. Is there a pressure relief within the cooling circuiy when the thermostat is closed? or dose the system pressurize unevenly as the pump spins up on start?
Phil Stafford

> Is there a pressure relief within the cooling circuiy when the thermostat is closed?

No but there is a bypass pipe, which does alows water to flow even with the heater off and the thermostat closed.
Will Munns



I also have an unusual coolant leakage, I only drive my mg at the weekends. Usually after it has stood for a week you can see a minimal amount of coolant about a teaspoon worth on th floor. The only place i have identified it coming from is on the exhaust box which doesn't make sense. I can't trace were it originates from before this any ideas as to the cause etc.
Simon B

Coolant or water? Daft question I know - but you need to be sure.

No cooling system should drip coolant under any circumstance: it's a sealed system.If it does drop coolant on the floor, then you have a problem that needs to be identified.

If the leak only occurs when everything is cold, then I'd wonder whether one of the unions between a rubber hose and metal pipe is weaping? Jubilee clips are notorious for uneven clamping forces (the clips that Mike sells are much better in this regard) - so with aging rubber perhaps this is a potential point of leakage?
Rob Bell

Also - dont forget that in the case of an *F* (as opposed to a *TF*) the Hydrogas system uses a water/anti-freeze based fluid that can leak and looks just like coolant!

Ted
Ted Newman

it is coolant, the floor of my garage is coated light grey, so its easy to see things. i'll check all the hoses and clamps etc. tonight.
simon b

G'day Phil

A few months ago I had a similar problem with a very small pool of green liquid appearing on my garage floor - the pool was on the passenger side of the car when looking from the rear of the car. There wasn't a discernable difference of the coolant level in the expansion tank, so perhaps, if you have noticed a drop in the level in your tank, then maybe your leak is more serious.

In my case, it turned out to be faulty hose clips which have since been replaced - this appears to have solved that problem. I've also had my coolant replaced since then and everything appears to be ok - touch wood (he says, touching his head).

Whatever the problem mate, I'd get the car down to the workshop ASAP and get them to check it out.

Out of interest, is there any mayo on the oil dipstick?

Cheers,

Phil

Phil

No mayo. I had the HG replaced recently, hence the coolant change and bleed. MG Workshops replaced the hose clips and pressure tested the system, including leaving it under pressure for hours with no change in the pressure and no leaks. The small pool of coolant seems to be under where the header tank overflow discharges (under engine towards passenger side) Which is why I asked the question about pressure relief. I the pump for some reason produces a pressure pulse that forces coolant past the cap on starting this would explain why a static pressure test would not show anything wrong but the engine may stall lose small amounts of coolant.
Phil Stafford

Phil, you have coolant leaking past the expansion bottle cap? If so, then it is very likely to be faulty - and not holding the required 12(?)psi...

Replace it and the coolant loose should be solved. Coolant on the floor is still rather likely to be a problem hose clip I suspect.
Rob Bell

Rob,

I suspect you are right. I am on my 3rd cap in 40,000km with the previous one leaking a lot more than the current one. (If that is the cause) The problem is that the caps test OK on the pressure tester. I guess its time to buy another cap and see if this helps.
Phil Stafford

> I am on my 3rd cap in 40,000km

Great reminder to me. ;)
Need to buy another spare. Installed the fourth within 3 years and 80k km.
Dieter K.

This thread was discussed between 03/02/2004 and 06/02/2004

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