Hey guys so today on the way home my car started to creep up to the middle of the temp gauge on the way home from work. It was only in the mid 80's so it is going to get hotter. What could be causing this? I know the rad is good since I replaced it and I can hear the clutch fan spinning when rolling forward a bit.

I think my thermostat is sticking closed because back when it was cold it would get to operating temp then sometimes go above then come back down. It would only do that at cool temps outside. Never drove it when it was seriously cold.

I really hate to flush the radiator since I just put all new coolant in it a couple months back but if that is what is needed along with the thermostat. Oh well...

 

You don't need to drain all the coolant to replace the thermostat. When you unbolt the neck it's under a little will pour out, but it's near the top of the system. Just make sure to get a new gasket and scrape the old one off.

 

Is it getting warm in stop n go traffic or on the highway? If stop n go then its probably the clutch
fan not engaging. If its on the highway, then its the cooling system, either radiator or tstat or
waterpump etc etc.

 

It's supposed to be right in the middle or a bit towards C...where is yours usually?

 

Normally it's at 1/4 to 1/3 from the C Mark.

 

the gauges sit in different places depending on the year of the car.

the 79-83 cars normally sit at about 1/3, which is about 85c, and something like 95c is in the middle. and H is 110c.

84-85 normally sit a needle width below halfway, which is about 88c, and a needle width above half is 91c. the first line at C is 65c, and H is 110c.

if the radiator is new, but the thermostat is unknown, the thermostat should be looked at/replaced. Mazda or NTC only please.

i put a bunch of thermostats in a pot and had a cookoff, and the OE Mazda stat not only seals the bypass, but it also opens faster and more than the aftermarket junk, which goes under the trade names stant, and gates.

 

Interesting, my 83' usually ranges between 1/3 and a hair under 1/2 on the gague, not sure why the movement. Only time I saw it hit 1/2 was when I was driving at a high rpm in the mountains, I backed off quickly.

 

Yeah the FB gauges are little different from the SA ones. Its ok if it gets to 1/2 when
pushing hard like that, especially if you are around 5-6K rpm constantly while
doing the curves. Good to always keep an eye on it. '

One time I was driving my car back from cars and coffee and my temps started going
up a lot as I headed home. Babied it some on the way home. I had a plastic bag
that got sucked up on the highway blocking the oil cooler and rediator. DOH!

 

I'd replace the thermostat and the radiator.

 

if you think about it, 65c on the cold mark, and 110c on the H mark, only gives the gauge 45 degrees of range, so it should move around some.

 

i tested the gauge in my FC and that one is REALLY weird. it uses the same range, 65c is the cold mark, 110c is the hot mark, but, between 0-75c its like an FB gauge, accurate, but damped. between 75-95c its range of movement is teeny, so the needle doesn't move at all. and then 95c up is really accurate and not damped at all.

 

Ditto on replacing the rad, I had to replace mine after less than 20yrs with the same symptoms. Turns out I had lost and continued to lose several rows of cooling fins from plain rust!!

 

The radiator has already been replaced hence the new coolant a few months ago. I flushed the system and that seems to have helped. Also when i went to swap the thermostat out it had a 170 in it. So I left it in there. Will only get to the middle now if I am sitting in traffic 95+ with the A/C on. The idle up also doesn't work when the A/C is on so that isn't helping the fact either but I usually just rev the engine up to 1200 while sitting at lights to keep the fan going.

 

I had this same problem. My fan sounded like it was engaging well, but it actually wasn't. I replaced the fan clutch with a used one and it works perfectly now. With fresh coolant, a new radiator and a new fan clutch, my temps stick right above the second tick on my 85. I don't believe it ever goes above 1/4 even on the hottest days unless I have A/C on with the original 32 year old working thermostat. I do however always keep a thermostat in the glove box just in case.

 

Sounds like me. I am planning on going electric once I swap my motor in. Any one have a suggestion on what relay kit is good for the taurus fan?

 

Davies Craig 0444