A couple of weeks ago afetr blasting up down the motorway on a few trips the rad on my Grand decided to dump its load when I got to work, filled it and limped home, checked the Rad and it was toast, and I mean rotten.
Changed the rad and put a new stat in it,filled it up, ok for a couple of days then one day on the way to work, takes ages for temp gauge to move, no heat, check coolant and its lost some, only a couple of litres. Thought it could be air lock so fill it up again, on my travels again, same thing happens, lost coolant, only intermittent heat, temp gauge up and down. Lots of gurgling noises from the system and the reservoir, put the old stat back in just in case it was that, check the heater pipes are not full of air. Refill and watch it on the drive.
As it warmed up, top hose getting hot and starting to expand, heater pipes cold, then it seems the pressures buliding built up so high that coolant is pissing out of the rad cap and also blasting into the reservoir together with loads of bubbles, turn it off still loads of coolant together with bubbles going into the reservoir until the pressure drops.
Change the cap, still no heat, top and bottom hoses hot but heater hoses cold and coolant blasting into the reservoir.
Now I think maybe the pump is toast although I changed it about 2-3 years ago, its as if there is a blockage somewhere could be the pump I thought.
Changed the pump this morning as I had one spare, old one looked ok, started up and now still some pressure although the heater hose (in) was hot the heater hose (out) was cold, still no heat but temp gauge reading hot. The pressure went down when the bottom hose started to leak but still bubble city in the reservoir..
So it seems the old rad probably blew due to the pressure and the new rad has just pushed the problem elsewhere..
Does this sound like the head or head gasket has gone? would that explain the pressure build up and bubbles in the reservoir..? Could there be a blockage somewhere?
Sorry for the long post and thanks for reading but while I like messing and having a go this is now doing my freakin head..
Any help as usual gratefully received..