Overheating problems

You could have a faulty radiator cap that is not allowing the system to pressurise.

A quick test for a leaky head gasket is to undo the radiator cap first thing in the morning (having driven it the day before, and not touched the cap) if there is a hiss of escaping gas then more than likely there is a leak.

(Others will tell you this doesn't happen, but it did for me on the 4 cars that I have had with head gasket problems over the years. )

The proper test is done by sampling the water and testing for combustion gases.

Thanks for the replies. I bled the system and there was quite a lot of air in as I had to replace a lot of coolant. Took it for a test drive and could hear the coolant bottle bubbling as I was driving along. The rad cap was quite easy to untighten compared to others so I've ordered another one which will hopefully solve the problem.

I didn't knowe the radiator cap had such an important job to be honest I just thought it was to stop coolant falling out!

If she's losing coolant and it's not in the expansion tank but unable to return to the radiator due to a possible faulty radiator cap, it will be the head gasket.

If it were the rad cap you'd have excessive coolant in the expansion tank and s hose would be sucked in so it looks like it's collapsed.

Get it tested at a garage for exhaust in the coolant asap. That's what your air will be.

Otherwise, sooner or later she's gonna break down and or boil it up so it really warps the head if it is the head gasket. If its not, then great. Just do some checks rather than guess and hope.

A compression test may show a leaking head gasket to the coolant too if you have a compression tester.

Kirkynut

I have since found out that after the coolant bottle blew off, my sister did not top up the radiator, just the bottle, so there wasn't enough coolant at all. When the rad cap arrives I will take it for a drive towards a garage and see what happens. If the problems persist I'll take it straight in to get the head gasket tested.

If it is the head gasket is this a particularly difficult job on a Jimny M13AA engine? If so how much could I expect to pay for labour?

Sorry mate but I can never remember what engine code is what.

Single cam engine is simple, twin can slightly trickier but to a garage, neither are hard, that's their job.

Price wise I'm out of touch I'm afraid. Maybe £2-300

Kirkynut