Water temp issue

[Bushbasher]

I've got a bit of an odd problem that I can't seem to cure. About 6 months ago or so my engine temp suddenly decided it wasn't going to run up to temperature in a timely manner any more and the car started running cold, if you believe the temp gauge. So where the needle was and should go from cold up to somewhere between the N & O within a couple of minutes once you get rolling of a morning it started taking 30-40km to just get into the "Normal" range. I figured it must be a dodgy thermostat stuck open so I changed it but that made no difference. Then I thought there might be a blockage of some kind down the back of the head to where the temp sensor is, plus my thermo fans were playing up AND I thought the replacement thermostat might just have been a dud maybe so I flushed the motor ALOT, put another new thermostat in and changed the thermo fans, still no change. In fact in the dead of winter the Fairlane was actually struggling to get going under load for the first 2 minutes which meant the gas converter was running on the verge of freezing up till some warm coolant began to flow through it, (it never did this before). Then I thought it might be the temp sensor itself causing the problem so last week I changed that too but still no change!! What the hell could it be and am I missing something? Is there a second temp sensor somewhere that might be faulty? The only other thing that may or may not be of relevance is that I changed the water pump a while back....twice, but that's another story. So does anyone have any ideas about where I might turn to next because if my temp gauge is to be believed then I'm basically running cold most of the time and it takes a hot day and a lead foot or hill to push the temp gauge up to where I'd expect it to be. Once it's up there though it does tend to stay there which is also confusing.

Any ideas anyone???


Cheers
Bushbasher