Calibra coolant light

Hello all!
I have a p reg calibra which is nice!!! and every now and then the
coolant warning light comes on there is a hissing noise coming from the
tank but the lid is on as tight as i cant get it and there is no loss
of water (leaks) when the car is staionary. when im on the motorway it
never comes on but when i slow down it does. Also the car has not hot
air when i turn the blower on but when it is not the air is warm im a
bit stumped on this one can anyone help me with this.

Also my wife has a vectra and it seems to be kicking out alot of
exhaust (steam i think) and the car sounds like a deisel and its a 2
litre petrol sri n reg the car has the same engine as my calibra but it
has now power in te lower rev range but is snappy on the odometer reads
over 2.5 revs is this the head gasket by any chance as the car is under
performing so badly?????

 

And another thing! have been reading the ads here and uncovered a few
more things about the calibra which now concern me the temp guage
always seems to be low between the 90 and cold line untill im staionary
then it warms up however sometimes it can run midway up the gauge where
i think it should be (btween 90 and 100) it went above that but im not
to sure the fan kicked in as the temp nearly hit the red lines. the car
seems to be drinking an obscene amount of fuel its vosting me a
fortune!!! it seems to me after reading the articles that it might be
the thermostat can you confirm for me pleeeeeeease!!! the fan will only
work on full blow which is a bit of a nightmare is that normal????

 

And another thing! have been reading the ads here and uncovered a few
more things about the calibra which now concern me the temp guage
always seems to be low between the 90 and cold line untill im staionary
then it warms up however sometimes it can run midway up the gauge where
i think it should be (btween 90 and 100) it went above that but im not
to sure the fan kicked in as the temp nearly hit the red lines. the car
seems to be drinking an obscene amount of fuel its vosting me a
fortune!!! it seems to me after reading the articles that it might be
the thermostat can you confirm for me pleeeeeeease!!! the fan will only
work on full blow which is a bit of a nightmare is that normal????

 

Sounds like the thermostat is stuck open to me and not letting the engine
warm up properly. I used to have a 1991 Calibra 2 litre 16v and before that
a 1989 Cavalier 2 litre 8v and never had any complaint about the heater not
performing as expected.

Ian

 

check the thermostat.
whip it out and stick it in a pan of water then bring to boil
does it open.?

mike