I think it was the thermostat Jerry, the garage replaced it and said it was closed. The 1st I knew about the issue was on the A303 on my way to a meeting in Salisbury. The car indicated on display on the dash and the gauge went right to the top. I pulled over when it was safe to do so. When I popped the bonnet up and saw that fluid was leaking from the bleed valve on the heater pipe (it's plastic) on my 07, called the AA and they performed a temp repair by putting a screw in the hole where the bleed valve, it worked perfectly, Temp stayed on 90 all the way back. Went to Alfa get price for new bleed valve and was informed that I would have to buy the whole lot about £100 and a fair bit of labour. Ordered the part and Alfa said it should be ok to drive. The next day on a local trip the temp gauge raised to the top and indicated on the dash that "excessive temp in radiator".
I pulled over and checked fluid levels and it appeared that fluid had come out of the coolant bottle. I took it to a mate of mine who has a garage of his own and asked for his advice, we checked for leaks and check pipes the main radiator pipe was not getting hot and found no leaks, not even from the temp repair. Not hot air either from the heater.
We done a head gasket test with car on tick over and the test was negative, not convinced we decided to do it again with a little throttle applied and this time the fluid turned green
It appears to be causing back pressure under heavy acceleration?
So we knew what was wrong, took it to Alfa to ask for a price for a new head gasket and they wanted around £1700 to do the gasket, and another £400 for cam belt & water pump.
Asked my mate if he fancied doing it, he said he look into it and said he would, he is not a one man band has 3 other mechanics and one had done a few Alfa's so this was a tasty project for him.
And now after the head had been done we can't get it to start. There was a bit of water in the engine so we thought it might be injectors, then ECU or fuel issues. So 2 weeks before Xmas she went to Alfa where they told us it was compression issues and something to do with the injectors????
They say it needs a new head.
I reckon If I get somewhat near what my loan is on it I might be tempted to get another, maybe a Brera. I don't know.