Hey fellas. My 92 Firebird 305 TBI has been giving me a tough time. I have been experiencing increasing cooling problems over the last few weeks. I was under it the other day and noticed some coolant coming out of the weep hole. I went down to the store and bought a Carter high-flow water pump and installed it on my car. The cooling was better, but still needed work. What happens is that if I'm on the highway, the temp stays where is should, but once I stop, the temperature creeps up to almost overheating. As long as I start driving again, the temp comes down again. I noticed the other day that when idling, the temp was about 230 and the fan wasn't coming on. I decided to wore the fan so that it would always run as long as the ignition was on. Before I did this, my dad suggested that I check the coolant temperature sensor. I went and bought one, but haven't put it on yet. The thing cost me $25, so I'm going to be pissed if that isn't the problem. I also replaced the thermostat with a 180 degree one. Does anybody know what might be the problem?

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1975 Firebird - Pontiac 350, TH350, 27k original miles, rustbucket, ongoing resto project

1992 Firebird - 305 TBI, 700R4, sport appearance package, t-tops, flaming red, 89k miles, Weiand 360 air cleaner assembly, CAT Power Engine Parts race underdrive pulleys, more to come....

 

The coolant temp sensor has nothing to do with the fan coming on. There is a fan switch that does that, it's in the pass side head.

The factory fan switch is designed to turn the fan on at about 230-235°. As far as the factory is concerned, 230° does not constitute "overheating". Furthermore, if you put a new stock fan switch in it, it will still turn the fan on at something around 235°. That's what these cars are supposed to do.

It doesn't sound to me like you have a problem. It may be that you would like your car to run cooler, which is easy enough to do; but everything you have described is perfectly normal and correct for the stock cooling system, it is not broken, so you may wish to modify it but you don't need to "fix" it.

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"So many Mustangs, so little time..."
ICON Motorsports

 

Like said there doesn't seem to be a problem. These engines are designed to run a little on the warm side for emission purposes. But I understand I wouldn't want my car running at 230* either. Try some Water Wetter, supposed to drop coolant temps up to 30*, I've heard good things about that stuff.

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2 Tickets to game= $250
Gas= $20
Sitting 20ft. from MJ= Priceless
'86 IROC T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK HEADERS Hooker CatBack
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat, just switched to 180* b/c of winter coming and going to college in the mts.
3:73 Posi Rebuilt 700R4
B&M Megashifter, 5" Autometer Tach w/shift lite

 

I've heard a rumor that there is a fan switch from the Buick turbo Grand Nationals that turns on the fan at a lower temp than the stock Chev switch, and it can be used on our cars. Any truth in this??

Alternately, there are aftermarket switches that turn the fan on at 200 or so.

 

One thing, though - my fan USED to run at about 210. I thought the fan was dead, so I wired it directly to the battery and it worked. My car runs hotter than 230 sometimes, like almost to the red. It runs so hot that the coolant boils off after I let the car sit.

Has anybody wired their fan so it always runs when the ignition is on? I'm probably going to do this, it'll run cooler all the time and I don't think it'll hurt anything.

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1975 Firebird - Pontiac 350, TH350, 27k original miles, rustbucket, ongoing resto project

1992 Firebird - 305 TBI, 700R4, sport appearance package, t-tops, flaming red, 89k miles, Weiand 360 air cleaner assembly, CAT Power Engine Parts race underdrive pulleys, more to come....

 

i am also having cooling problems ever since i installed a shift kit, car used to run under 200, now it heats up in traffic very fast, but if they car is moving at a good pace it doesnt, it does have an external trans cooler on it, it also runs inline through the radiator, changed thermostat, also wired fan2 directly to a switch so its always turned on, cant seems to solve the problem, i dont like running over 200 since the car was set up to run under 200 and never used to run over till i put the shift kit in, any ideas?

 

it's easy to wire the fan to come on when the car is on, just ground the green wire that goes into the passesnger side heads. Sounds like to me you may need a new cooling fan motor, that may help.

 

Check to see if the coolant flow isn't restricted. Possibly a clogged radiator. One way you can check for restricted coolant flow is to watch the lower radiator hose and rev the engine (when its warmed already). If the hose sucks in or "collapses" there's a problem right there.

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Red '87Formula Firebird
-mostly stock 5.0L LG4 w/cowl induction setup borrowed from '83 TA and T5 tranny.

My newest Ride:

'85 Silver L98 Corvette w/4+3 manual tranny. not bad for $3500.

 

Well, the cooling fan does work. I opened a little section of the wire and ran it directly to the battery and it came on and ran fine.

As for the lower radiator hose thing, what if your lower hose has that spring in it to keep it from crimping? I don't think there is a clog because when I put the new water pump on it, there was a lot of coolant moving through that hose.

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1975 Firebird - Pontiac 350, TH350, 27k original miles, rustbucket, ongoing resto project

1992 Firebird - 305 TBI, 700R4, sport appearance package, t-tops, flaming red, 89k miles, Weiand 360 air cleaner assembly, CAT Power Engine Parts race underdrive pulleys, more to come....