[littebluepony]

Recently my last few driving trips I've noticed my temperature gauge sporadically rising. Initially it would only happen while stopped and immediately drop back to it's normal position slightly above 'C' upon moving. Now the gauge spikes just below 'H' frequently. If I stop and let the car idle I can watch the gauge go up very quickly. I'm not sure if it's a sensor issue or the thermostat not opening and closing correctly. Also the air coming out of the heater gets significantly cooler while stopped.

[sleeper_inc]

Get a new thermostat and if that doesn't fix it than get a new gauge sender

[92'Grey-Ghost]

Make sure your cooling fan is working. Had the same problem with mine.

[littebluepony]

The electric fan is working fine.

[icemann427]

Hi

The thermostat is potentially the only problem. However, once you replace it you may still have a problem. In a car that old, the radiator may be getting dirty, and as a result, need cleaning. You can try a radiator flush that you can buy at a parts store and try to clean it out at home, however, you may need to take the radiator to a radiator shop and have it cleaned out professionally...Or just buy a new radiator.

Also, once you have the thermostat and/or radiator installed, fill the system with the normal mixture of water/coolant. Open your interior heater controls to allow the water to flow through your whole system. Run the engine for a while to let the thermostat open and for the water to flow. The thermostat won't open allowing the water to flow until the engine is good and warm. Once the engine is fully warmed, turn off your engine and let it cool. After it is fully cold, open your radiator and fully fill it again along with the proper amount of water in your overflow container. Only once you have gone through these steps will you cooling/heating system be full of water...And the 2.3L system needs every drop of water it can get. Good luck

[littebluepony]

I actually just got finished putting in a new thermostat with no improvement. The temp Gauge is all over the place and the heater goes cold unless i have my foot on the gas. I saw the post about the air pocket in the heater core.
My question is where is the pickup for the temp gauge located? The hose from the engine to the core is hot. The one coming out is cold so i'm thinking that water isn't flowing through core unless there is the extra pressure from the high rpms. If the gauge sensor is that plug spliced on the hose going into the heater core than it would seem that the hose just gets extremely hot because there is no flow. Which would indicate that the gauge isn't reading correct overall fluid temp (if this is true ford picked a terrible place to put a sensor). The font main radiator gets warm as well as both in and out hoses to it, so it appears fluid is circulating correctly there.Also if i'm driving down the highway and turn on the heat full blast the temp gauge drops almost instantly in response to heat from the heater...that seems to support my theory at least.

[littebluepony]

-Fixed-
Here's a lesson. After reading through repair manuals and numerous forum posts, changing the thermostat, going over tons of things and still being stumped. oh and finding a nasty little slow leak in my radiator (to be fixed when my ordered one gets here) I had one of those moments that we all have at some point while trying to work through a stupid problem we know we should be able to fix.
I had the engine idling, I was checking to make sure the right hoses were warm etc as I was staring into the engine compartment mulling things over in my head as my eyes fell on the coolant reservoir tank. The fluid was just above the 'hot' line. All fine there...except I haven't put fluid in it since it just started getting cold around december. I thought "that looks like it's at the same level". It also appears to be completely stagnant. So I glance at the black tube that runs to the radiator, it looks fine...or is it? I look at it from the battery side and I can see the end of it and it's not where it should be. Wtf? Then i had that epiphany. I topped the reservoir off right when it started getting cold and I checked all that crap. Well just after that I got the car inspected and I remember being told they had to take the battery out to fix that little bracket that holds it in. The filler hose from the reservoir must have been knocked off when they put the battery back in. it runs right past the corner. So apparently the system was so low on coolant that the air gap in the system was causing a pressure drop at idle speed. Thank god these engines run so cold, even with so little coolant the engine is fine.

[sleeper_inc]

Wow, good think you noticed that. The walmart boys never would have. (had my car in there and they said my reservoir was low, checked it and it was fine, dumb fucks I swear)