Dumping water from the cooling system

My Rivage has a continuing problem I can't seem to solve - dumping fluid from the cooling system. Today I started her up and the coolant light was flashing and sure enough the coolant tank was empty. I have had a new cap so it's not leaking from the cap. Has anyone had this problem and can suggest a solution? It makes using the car, especially in summer, a bit of a trial in case it happens on a trip and I risk running the temperature way up. The temp gauge stays reasonable and my local garage can't crack it. It doesn't seem to be the radiator as I had that checked. When I had an MOT done on Friday there was a pool of water on the floor of the garage after a short trip to the MOT station. The local garage is pretty good and know the cars fairly well, but I can't afford to pay for them taking hours experimenting and I wouldn't think it was a unique problem. Help much appreciated.

It sounds like you already found the cause, you have a leak somewhere. I'd suggest parking on some cardboard and checking it periodically to determine the rough area and then track it back to source.

Also, look for orange/brown corosion around the engine which will point you in the direction of the problem. Check all hoses etc, back flush rad, change the stat.

Thank you for that, eminently sensible!

JSeaman said

It sounds like you already found the cause, you have a leak somewhere. I'd suggest parking on some cardboard and checking it periodically to determine the rough area and then track it back to source.

Also, look for orange/brown corosion around the engine which will point you in the direction of the problem. Check all hoses etc, back flush rad, change the stat.

On second thoughts I'm not sure it could be a simple leak. All the fluid seems to be dumped in one go and it seems to be when the car has stopped - as at the MOT station.

OK so the coolant system is pressurising then by the sounds of things, do you have access to a compression tester? It is possible that combustion gases are finding a path to the coolant system so head gasket is a suspect, might not be that serious but worth a check

Thanks again. Unfortunately I don't have access, but might try asking the garage I use to see if they understand your suggestion. Regards

Well, the compression test is as follows:

1. Go to your local auto factors and buy one (no more than a max of £20 though!)
2. Run the engine to normal operating temperature
3. Remove all 4 spark plugs
4. Get someone to hold the throttle open and crank the engine for 5-10 seconds
5. The compression tester will show a number which is the cylinder pressure in psi/bar, write this down

Once you've done all 4 cylinders post up the results and will tell you more

It's dead easy and I did a guide for mk3 supra if you're interested - check out www.mkiiisupra.net if that is any use to you