6 replies to this topic

[Hen1275]

Hi, I've had this problem on and off for a while now but as its coming up to winter I really need to get this sorted out. I have a standard 1990 mini cooper and I am loosing water from somewhere but only after I have done a journey and turned off the engine. I don't believe its loosing water when I'm driving as I wouldn't get far before overheating, judging by the large puddle which appears when I park up. Also when I'm driving the temperature gauge doesn't seem to get any hotter.  I've tried Radweld a couple times thinking it might be a leaking hose but that only temporarily solved it the first time and the second time it didn't have any effect.

Does anyone have any ideas as to what the problem might be?

Thanks

 

[stevelane]

I've had a similar issue which turned out to be an airlock. Kept finding a puddle under the rad from the overflow on the neck of the rad

[Guess-Works.com]

You need to pressurise the coolant system which will then show you where it's leaking from...

Find a garage or local enthusiast with something like this...

 

https://www.machinem...-pressure-teste

Edited by Guess-Works.com, 22 September 2014 - 06:53 AM.

[MrIan]

If you're getting a puddle under the rad (from the overflow??) then try a new radiator cap, I had the same trouble on my V12 XJS. While your driving the car you're getting air flow and fan drawn air across the rad / engine all keeping it cooler. Once you stop the engine there's a vast drop in cooling and it will get hotter / increase pressure, if this lifts the cap it'll overflow. Gives no sign while running but leaks when turned off after a few mins.

[Hen1275]

Hi, thanks for all the responses. It does seem to suggest that there isn't any pressure in the system because when I remove the radiator cap after its been running no air seems to get released. So I'll try a new cap first and if that doesn't work I'll take other action.

Thanks

[MrIan]

Yes that's a deff sign of either an obvious visible leak or duff cap. Make sure you get the correct cap too, not everyone knows they are pressure rated, fit too low a pressure one and it will open n chuck water out. The water system should be pressureised when up to temp as the water in areas gets to above boiling point, the only thing that stops it boiling is the pressurised cooling system of which the rad cap is the safety valve. Hence taking a cap off a hot engine makes the cooling water boil over instantly as it's not under pressure without the cap.

[maccers]

I had this 2 days ago and its turned out to be the water pump weep hole - apparantly when this leaks the pump is dead.