Overheating ( again )

I have read the various threads re; this problem and I am going with the expansion tank and associated hoses first.
Water seems to mysteriously disappear and then reappear I had a drive to the beach with the dogs( about seven miles) the expansion tank was normal on leaving but when checking on arrival at the beach the tank seemed empty! Left it until I came back, still apparently empty,topped it up to the mark and drove to local shops, came back to find a considerable amount of water under the vec, but on checking the expansion tank found it still at normal level, drove home temp gauge started to go above normal but went back to normal but after leaving it to cool went back and checked tank, empty!
Using available tools (big gob) I pressurised tank and was rewarded with a fountain of water from an apparently empty tank?
Any ideas:confused2

Expansion could have crack in.the go about half way up but will only leak under pressure.

Or the cap seal has gone causing it to leak unxer pressure.

Can be a sign of head gasket on way out

haigy said:

Expansion could have crack in.the go about half way up but will only leak under pressure.

Or the cap seal has gone causing it to leak unxer pressure.

Can be a sign of head gasket on way out

Click to expand...

I have only had this problem since I had the P seal repaired, could this have a bearing on the problem do you reckon?

any joy?

trax said:

any joy?

Click to expand...

Tried bleeding it a couple of times as I thought the garage might just have "topped it up" after changing the P ring no change, earlier today decided to remove the stat and flush the whole thing out, did that earlier, tried a couple of tentative short runs, all OK, then took her out on a longer run ( the beach of my troubles) seemed ok, left her for a while, came back water levels still ok came home the long way round and beasted her a bit,leaving it for a while before going out to check water levels.
On the runs she seemed fine other than she never got quite to normal temp, which is normal with the stat removed if IRC from my spannering days
Aye, water level still at normal, will drain and replace stat and top up later this week, hopefully will then be able to tackle other issues, intermittent speedo, stuck window........

progress then

trax said:

progress then

Click to expand...

Aye, I seem to be removing uneccesary bits as I progress

Have you tried burping the system? squeeze the hose while the cap is off


My header tank has a split above the water line it hisses steam when hot but the level is as it should be it dose not disappear and reappear as you describe