Why is my Firebird getting hot???

Maybe someone can help me figure this out.
My 89 Formula has dual electric fans. A while back one of the relays burnt out and the 2ndary fan wasn't coming on at all, so my engine was overheating. I rigged the fans together so that both fans come on and stay on together.
This caused the temperature to never even reach the midway point of 220 on the gauge, so my car was running cooler than normal just fine. Also, to this point, I wasn't using my A/C because there was a problem with it.
So, fast forward to a month ago, I got the A/C fixed (it was a short in the power wire) and recharged completely. BUT, now my car is running at the midpoint of 220 and even hotter. It's gotten about 3/4 of the way to temperature redline on an almost daily basis now!
This usually happens in slightly stop and go traffic, and if I'm on the open road, the temperature gauge needle will move back down to 220 or a little cooler. But, it will still fluctuate a little within a very small time frame.

Could this have something to do with the A/C operating again? I was told that if my belts area little loose, it could be causing the engine to work harder now that the compressor is engaged.
My coolant level in the radiator is good, but I used the 50/50 premixed stuff. Should I add more straight antifreeze to strengthen the mix?

Any ideas???

are you running your AC while youre checking the gauges? cuz your car will run hotter when you run AC.. also, antifreeze cools engines SLOWER. water is actually the best liquid to use.. but you use antifreeze so..well, it doesnt freeze and crack your block, so it doesnt start boiling, and so your engine doesnt rust.

It's mating season...what was the question?

This is the same problem my camaro had. I replaced the relays, made sure the wiring was correct. Sorry because I can't say if it ever worked because I attributed my overheating problem to the transmission, which I'll never know if it was the problem. If this heat has been going on for a long time, it could be hazardous to your engine and might have caused long term problems...g/luck with that of course and I hope everything works out!!

Have you by any chanced tried changing your thermostat? It could be stuck in a closed loop cycle.

I replaced the thermostat just a few months ago. I'd hate to think it's a faulty thermostat. It's been running fine before the A/C was used.

The AC will cause the car to run hotter, but what you describe sure sounds like an issue with the thermostat.

Has the radiator been flushed recently . The A/C evaporator core is warming the air before it gets to the radiator . Thus not enough heat being removed from the coolant from flow restrictions . Ignition timing may not be advancing properly at highway speeds causing overheating . Just some thoughts. Rob

Hmm, all good ideas guys. I think I have some good leads here.

One thing we found re; overheating in specifically firebirds in stop and go traffic especially with ac on is the air dam under the front end is broken or missing, the firebird in particular has so little grille area the bulk of the air flow from the cooling fans comes from underneath the carover the air dam. Usually this black plastic piece breaks off at parking lot wheel curbs. The firebird air dam is in front of the front wheels so hits the curb before the wheels. the car seems to generate enough airflow when moving idling is the problem, this G M bulletin covered 82 - 88 but if I remember right yours is similar. Hope it helps!

Penski

I Think I Know Exactly Whats Going On The Same Thing Happend To My Camaro And Its The Fan! I Changed The Thermostat And The Fan Sensor And It Stil Overheats ...so I Busted A Mickey Mouse....what I Did Was Cut The Cables From The A/c And Connect A Wire From The Ac Wires To The Battery And ..vuala! The Fan Turns On...but Careful To Disconnect When Then Car Is Off!! Or It Will Eat Ur Battery !! If I Were U I Will Take It To An Electrician Where They Could Do A Profescional Mickey Mouse Job ...hope This Helps

honestly there is nothing to worry about because aslong as an engine made after 85 the engine is designed to run approximately220 to 240degrees your fans come from the factory set not to come on until two thirty four

I replaced the thermostat just a few months ago. I'd hate to think it's a faulty thermostat. It's been running fine before the A/C was used.
A good idea is to warm up some water in a pot on the stove and when it just starts to boil put the new thermostat in it to see if it opens up... just for future reference. I went through 2 thermostats on my 96 chev pu when i had it...