water level low?

Hi, Herbie,
You don't say what car you have, but the same will apply to any car really. There's many reasons why you could be losing water. When you leave the car standing on a dry surface, any sign of a damp patch underneath suggesting there's leak from the system? Check all the hose connections, are they correctly located and tight. Is the car overheating? Even though your temp gauge is saying no, is it reading correctly? You could be losing water through a cylinder head gasket leak into the oil or it may be leaking onto the outside of the hot engine and boiling away before you see it. Check on the dipstick to see if there's any sign of water in the oil. Sounds a little daft, but are you putting too much water in the system, as this will cause water to be lost when the pressure builds up and it will tend, through capiilary action, to lose more and the level will drop below the correct level. Only fill to indicated level on the expansion bottle.
Only sure way to tell where water may be going is to have a garage do a pressure test on the system. They'll fit a cap on yhe expansion bottle and pressurise the system over what it should run at and hopefully show where any leak is. You may also need a cylinder leakage test to show possibly a dodgy cylinder head gasket problem. This is done by fitting adaptors into the plug holes and pumping compressed air into the engine to show any leak in the cylinder head gasket. Not all garages can do this. Be quite clear, if you do take it in for this to be done, that they don't do just a compression test. This may show a drop of compression in the cylinders, but it doesn't show where the problem is. A cylinder leakage test will. At the end of the day, you may be better off having these two tests done, as you can spend ages trying to find the problem yourself. I've done it! Best of luck!!!

Denis Langley
March 2006