(No) heater

[krustybiker]

Hi, new on here, first post. I've seen some posts regarding my problem, but I've got an extra concern. The heater packed up over a week ago, garage said they bled it, and it worked, until today. Temp gauge is normal, no scary lights. I checked the header tank, it seemed overfull. Later, after it cooled (about 3 hours) I released the filler cap, water spilt out, under some pressure. My query then, is it possible there's something more sinister? What's causing the pressure. I understand cooling systems are pressurised, but this seems excessive. Also, why has the problem returned, is it such a common fault?

[dixieds]

could be a massive air lock.or wrong cap rating thats the cheap option of course the worse one could be head gasket

[krustybiker]

I fitted a new header tank cap, it's rated at 21 psi. When I took the old one off, loads of pressure again. Ran the engine for a minute or two with the cap off, more bubbles in the tank and heater worked ok (not great) for about a couple of hours and cold again. I'm going to give it one more shot at a proper bleed, if that doesn't work, it's off to the garage. I know it's not always the case, but there's no trace of oil in the tank or water in the oil.

[dixieds]

good luck hope it turns out to be something cheap

[krustybiker]

Well, it appears it WAS just the header cap. I have been on a couple of long runs, the first one was a bit chilly in the car, but the last ones have needed the heating turned down! I've had visions of head gaskets, water pump and heaven knows what else. Fixed for less than £10.

[dixieds]

great news glad it was cheap

[krustybiker]

Famous last words! I've been losing heat again over the past couple of days. Now dreading it is the head gasket

[Altransit]

I seem to remember that some of these had a restrictor in the small pipes from the header tank to the radiator, and these can clog up.
You may want to try and bypass the restrictor with a new pipe, or remove the restrictor if you can, and see if the water flow improves