SII - Coolant Loss

[JC]

Over the last two months I've needed to top up the coolant on two occassions, each time with 4 pints of coolant - the last time was when I checked the car over before a run on Sunday (that, of course, I missed!!)

Tonight I took the car out for a 3 miles warm up tonight - there was no coolant loss and no drips underneath!

I've checked the engine oil - the level has not increased and the filler cap is very clean. So I'm assuming this is not a cylinder head gasket problem.

The driver-side footwell carpet is damp - but not 8 pints wet!!

My only history with the cooling system, other than changing the coolant, was getting the radiator re-cored about 10 years ago.

I'm in a dilemma - do I wait for the problem to re-occur and, if it's a leak, identify it ; or drain/flush the system (32pts of coolant), assuming there might be an airblock caused by something stuck in there?

Any thoughts would be gratefully received!!

Cheers, JC

[/list]

[mgcjag]

Hi JC.....If you have had the same coolant in for 10 years it would be a good idea to replace it......you need to find out why the carpet is wet....consider putting in some Bars leaks just to seal up any leak you may have......ensure you have the heater set to hot so the coolant circulates through the heater matrix..... Are you topping the system to the level in the expansion tank.... Steve

[abowie]

Coolant level is slowly dropping. You have wet carpet. Logically the heater pipes are leaking.
Bars Leaks is a very good idea. Don't forget to turn the heater on when you put it in.
If that doesn't fix it your next step is to check the pipes.

[markc555]

Could you have put the radiator cap on the expansion tank and vice versa?

The rad cap is a plain unpressurised item and the expansion tank cap is a pressure relief (7lbs) item. Put them on the wrong way round and you'll lose water out of the expansion tank as the system heats up (and expands) as the there's no seal on the expansion tank. Yes I have made this mistake myself

Cheers

Mark

[Alan N]

Hi
I had similar problem took ages to find had a large crack in the rear of expansion tank only leaked under pressure.

Alan

[JC]

Well it seems that I've solved the problem - or rather I've found a leak, there could be others. i'm doing some tarting while I've got components out (looking for leaks) and I'll test later.

Alan - Similar problem to you, i had a crack where the inlet pipe meets the expansion tank

Markc555 - The cause was indeed caps. before the leak I'd exchanged the caps - intentionally because they where the wrong way round. Previously no water had leaked because the rad cap was 20+ psi!! I'd innocently lived with this since I bought the car 20 years ago - I'm surprised the radiator didn't give way!!

Cheers, JC

[malcolm]

Foolishly, I was also always topping up a little, until I realised I was filling the expansion bottle too high. The hoses are quite low down on it. Worth noting maybe?