Engine overheating problems.

[Zeuszoey]

Need some help please. After a long period of being sat in the garage over the winter months I took out my Freda to clean and check levels to start using again, checked the coolant levels and when opening the cap I had a rush of coolant loss from the pipe and coming out from top of cap after the initial gush of liquid had calmed down I topped up coolant header tank and went to take out for drive, however after 5 mins on the road the temp gauge started to rise beyond its normal level of 11 o'clock, so drove straight back home and let her cool down.

This weekend I have preformed the bleeding process as recommended from searches on internet to unblock possible air lock and everything went fine, bottom hose from radiator got hot and fan heating in Freda working fine although I did notice when flushing old coolant out that the liquid had gone muddy brown colour, anyway took out van again today about 3 miles down the road and just pulling into fuel station heard a whistling sound under bonnet and temp gauge had gone way past 11 position, so opened coolant header tank and same thing happened again loss of coolant and gurgling sound from header tank, let engine cool down and topped up levels to get back home again which just managed to get back with gauge once again past 11 position.

I have bought a coolant alarm system which I plan to fit but would like to rectify this problem before I fit.

Anyway what I would like to know is what could be cause of these problems, I will try and bleed system again on Wednesday to see if this would fix or should I take out thermostat to see if this will solve problem.

Any advice would be greatly appreciated as I am not really great with engine mechanics.

Thanks in advance.

[Northern Bongolow]

did you open the cap with the engine warm, after it had been running for a while.
the coolant system is pressurized so if you open a hot system the pressure suddenly drops and the coolant will instantly boil.
the cap should only be removed when cool, or with care.

the repeated boiling sounds like it needs bleeding properly, dont run it more than necessary until this is done or damage may occur.

[Zeuszoey]

Thanks for your reply, when I first opened the header tank cap when I went to get the van out of the garage I opened it without starting it up so was cold and that's when I had the pressure go through the header tank hose and cap, today when I got to the fuel station I opened the bonnet and there was steam coming out of header tank cap, I will try another bleed on Wednesday to see if it sorts it out, when I bleed the system on Saturday I checked the lower hose was hot and the heating was working after I had checked these we're working I immediately turn off engine, should I have left engine running for a while to see if engine temp would go past 11 position and fan come on?

[rita]

I would imagine by the sound of things is you need (for a start)to have the cooling system cleaned out(checking the flow of the radiator)and a new thermostat fitted then bled.

Very unusual to have pressure in the system if the vehicle was not started after a few months, if it did at least it shows that there is no leaks.

[2newbies]

Hmmmmm.....When I have bled the system I've carried on after the the bottom pipe has got warm until there are no more bubbles.....Paul

[Zeuszoey]

I am going to try again on Wednesday, I have ordered new thermostat and will fit new one before I try to re-bleed system again, thanks for your replies and keep them coming as any advice on this forum has always been most helpful, cheers and wish me luck.