R53 cooper s overheating...help!!

[kildangan_kid]

I seem to be in a big spot of bother and could really do with some help. The missus bought a '04 cooper S a couple of months ago - smashing car to drive and handy run. But about 3 weeks ago it just randomly started to over heat. Kept getting more and more frequent, happening with absolutely no warning.

So I checked a few things and noticed that the expansion bottle seemed to be leaking a slight bit of water, but a losing a lot of pressure. Did a bit of research , turns out the expansion bottle and cap give big trouble on this model. So ordered a bottle and cap from conlans and fitted. Bit of trouble bleeding it but got there eventually. That was two weeks ago. Car drove like a dream after that.

Then last when she was driving home and heard "a loud bang" - I can't confirm this yet as I haven't seen the car yet, but started to overheat again. Without warning. It seems to still draining it's expansion bottle every time and I can't find what the problem is.

- I've checked the water pump , no noises , abnormal play or leaks

- no leaks or weeps from the rad , all the piping is fine and connections fine

- old expansion bottle was leaking from the seem where the top and bottom were joined. New bottle is perfect, no leaks or hissing

- the temperature usually fly's from halfway to the red in literally a second , no warning

- the high and low fans are working when they should , seemingly a issue with them too .

If anyone has any experience with this problem can you please help this has been wrecking my head for weeks and I need it sorted

Thanks in advance,

Adam

[JohnH]

Did you check under the oil cap? Any sign of mayonnaise? Is it the head gasket that's gone?

[kildangan_kid]

No mayo at all.. no smell of oil from the coolant.. car starts are drives perfect apart from this. No sign of head gasket failure from what I can see..

[kildangan_kid]

Just drove the car home , 10 miles and not a peep out of it. I just topped it up with water (it took 1.5 litres) with the blowers on full belt on hi temp. Left the blowers on driving back.

I'm so confused , where did the water go? It's not leaking anywhere and there's no real symptoms of head gasket failure.

I also left it running for 10 mins with no blowers on when I got home and the gauge didn't move a inch.

[Johny14586]

Had more or less the same issue with her cooper s awhile back. Turned out to be a hairline crack in the thermostat housing.

[Venom]

If its just water and no coolant it can use water which may explain that. Any damage to fins on the rad. Also a compression tester is 30 quid from an auto factors and would rule out a head gasket. How is the car performing? Any loss of power? Could the loud crack have been the water pump letting go? I hope not

[rebel.ranter]

Are these Cooper C a bad buy? I was thinking of getting one as a run around when the M6 next breaks down!