Hey guys, I've got a 94 Formula that is running a little too warm, its running at around 225-235 degrees, I stuck a 160 thermostat in it to see if that would help and nothing, wondering if it may be the raditator? The fans kick on and work fine the car just doesnt have the power it should. Gonna have it flushed and refilled and see if that helps.

 

The fan settings are prety high from stock to begin with, lot of them run warm.

 

Ditto,
Fans turn on around 229°F. Too high in my opinion but thats how GM designed them. Apparently they did that for better emmissions. If you put in a 160° stat, I would have your fans turn on at cooler temperatures like ~175° or so. I used a hypertech programmer to do this in my car but there are other options. Some people hardwire a manual switch to the fans but I don't really like that idea.

 

A new radiator fixed the same problem with mine. Now it runs around 170 to 180 with a 160 stat

 

you probably have some air bubbles. Did you bleed the coolant correctly?

Also, if your cap is not holding pressure, temps will rise ALOT, if you have a small crack in a hose or radiator then temps will go up. So you could very well fix it with a new radiator and new cap.

 

does it run at that temp at idle or like at highway speeds?

It's normal (if you have a stock tune) to run that hot when not moving very quickly. You can get a tune to fix that easy. But if it runs at that all the time then I would check to see if you have any coolant/radiator problems.

 

Hows a new cap affect temperatures at all? Granted, without a cap, the coolant would boil and youd have all kinds of air pockets showing up in your heads causing the gauge to fluctuate wildly and bigger problems brewing... but I fail to see how a new cap will decrease temps?

Anyway, just did the radiator in my g/f's '94 T/A and then did the water pump a day later after that went out. Still runs as it always has, around 210* unless you sit where it creeps up to around 230-235 when the fan kicks on. Opti's still good, still original...amazing considering the amount of water thats been dumped on it with numerous occasions. I think all that oil/grease has made it pretty water tight.

 

Your cooling system is designed to work at a given temperature under a certain pressure. Your cap needs to hold a certain pressure so that the system can maintain its pressure. If your cap is shot (not very common) it can't hold pressure and allows air to get into your system. If you get enough air in your system, you won't have any coolant flow in a reverse cooling system. Did you try filling up your g/f's without bleeding the system? If you did, the temp gauge would just run away. It happened to me a couple times when I forgot to bleed mine. A lot of cars have a "self bleeding" system but not ours.
I don't think that a bad cap would cause you to run hotter until, over time, it'll leak some fluid out and let air in, then cause you some problems. If the cap was totally shot (doesn't hold any pressure at all), then you'd just boil over.

 

Ive done the nightmare bleeding LT1 thing numerous times. It was very difficulut till i got teh procedure down to a ascience. Now I just put the car on a sloped driveway, and jack the front end way up, with the passenger side higher, open the screws, fill her up, and close the screws. No other bleeding necessary in my experiance. Saves a lot of time.