Toyota Carina overheating advice

[LV]

Hi, I am looking for some advice. I have a Toyota Carina 2 E reg, I recently had a core plug and a new radiator fitted. At this point my temperature gauge seemed to not be working correctly. We took it to the garage and it was checked, a new gauge was fitted and then it was run to see if t was working. Now the temperature gauge went to half (which is normal) but upon returning to the garage steam was coming from under the bonnet. The engine was checked and the water pump was working as was everything else. I was advised the next thing was to have a new head gasket the head skimmed and cracked checked, but if that didn't work it could be a crack in the engine block. We decided to see how it ran when it was all put together (as I was looking at a large bill as you can imagine). I ran my car for about 5-7 miles at around 50-60 mph, the temperature only went upto half and we returned home thinking all was ok. Upon pulling on the drive steam was coming from under the bonnet. When we looked the water was coming out of the overflow tank and we could hear the water was boiling in the overflow tank.

I am after advise as to what could cause this, has anyone had this happen to them. My car is now 28 years old and though on the drive she ran like a dream I cant understand the overheating and it not registering on the brand new temperature gauge (as it must be working as it went to half then stopped rising). Is this the head gasket or is there any other reason anyone can think of.

Any advice will be greatly appreciated, Thank you.

Lynne