'93 T/A running hot
07-23-2009, 12:16 AM
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'93 T/A running hot Ok another question guys...my '93 T/A seems to be having an issue with running hot. It will be fine then all of a sudden the temp shoots up. What could be causing this? The coolant level is fine...one fan kicks on when I turn the AC on but the reg one seems to be coming on right before the temp is reaching the red. We just replaced the thermostat...?????
07-23-2009, 01:41 AM
#5
Best way that works every time for me is:
Take the radiator cap off while its cold, top off the coolant, start the engine and stand there and wait for the engine to warm up. After you see your temp guage start to rise you want to squeeze the upper and lower radiator hoses rapidly about 10-20 times each, alternating back and forth from hose to hose. This will pulsate the air and water thats standing in front of the t-stat. Problem is, the air bubble is up against the t-stat and not the water, so it won't open because the water is whats getting hot. So by pulsating and pushing the water throguh the system it will move the air bubble around.
That should get the t-stat to open. Once it finally starts to flow and the coolant drops down, just top it off quickly while the t-stat is still open and keep topping it off till the flow stops.
That should do it.
***sometimes it can take a long time. if it gets too hot and it hasen't opened yet, shut the engine off, then restart it and keep trying.
.
Take the radiator cap off while its cold, top off the coolant, start the engine and stand there and wait for the engine to warm up. After you see your temp guage start to rise you want to squeeze the upper and lower radiator hoses rapidly about 10-20 times each, alternating back and forth from hose to hose. This will pulsate the air and water thats standing in front of the t-stat. Problem is, the air bubble is up against the t-stat and not the water, so it won't open because the water is whats getting hot. So by pulsating and pushing the water throguh the system it will move the air bubble around.
That should get the t-stat to open. Once it finally starts to flow and the coolant drops down, just top it off quickly while the t-stat is still open and keep topping it off till the flow stops.
That should do it.
***sometimes it can take a long time. if it gets too hot and it hasen't opened yet, shut the engine off, then restart it and keep trying.
.
07-23-2009, 01:59 AM
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Don't lt1's have a bleeder valve on top of the t-stat housing?? If so, leave the radiator cap off and crack open the bleeder screw. Once the coolant starts to flow out of the bleeder screw. Tighten it up. Put the cap on and let the car cool. Then just open the cap and top off the radiator if it needs it. That's how I use to do it on my 95.
07-23-2009, 07:34 PM
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Bled it, squeezed the lines...No change! I don't think the fan is turning on at all - AC fan workds. What would cause the fan to not turn on when the thermostat registers at a certain degree? I am assuming the thermostat is working since we just replaced it...
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07-23-2009, 09:35 PM
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A bad water pump won't cause it to overheat unless it's just absolutely puking coolant, and then it's not the pump causing an overheat but rather the loss of coolant. I'd second the motion for improper venting, and/or a dirty radiator or A/C condenser.
You know the pump is bad when it starts leaking out the weep hole.
You know the pump is bad when it starts leaking out the weep hole.
07-23-2009, 11:41 PM
#10
Did the coolant drop down ever?
If the coolant did nothing.....your t-stat is not opening...period.
If it did flow and you still overheat after you put the radiator cap on and go for a drive....it can be a dizen different things.
If you don't verify if the coolant is flowing.....you will never figure anything out.
The fans........they will turn on regardless of what the t-ststa is doing, the fans work off the coolant temp sensor in the head. If your fans are NEVER coming on no matter what...you found your problem.
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07-24-2009, 09:45 AM
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I am pretty sure the coolant is flowing! Can feel it in the lines...
Are there any "vents" that look like bleeders off the radiator? I had the car towed to the shop when the ignition module went. They said "all these bleeders were open all over the radiator and you had no coolant at all so we closed all the bleeders." Well, no one had touched any bleeders and the reason I had no coolant - which I told them - was because we had just replaced a lower hose and lost most of the coolant.
Are there any "vents" that look like bleeders off the radiator? I had the car towed to the shop when the ignition module went. They said "all these bleeders were open all over the radiator and you had no coolant at all so we closed all the bleeders." Well, no one had touched any bleeders and the reason I had no coolant - which I told them - was because we had just replaced a lower hose and lost most of the coolant.
07-24-2009, 04:24 PM
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I replaced the coolant temp sensor ran the car and temp was fine took it for a ride around the block three times and temp got to just under red...coolant IS flowing...fan kickes on but not until about 240 degrees plus and that is when the needle is almost in the red. I am so confused and so frustrated...
07-24-2009, 05:19 PM
#16
I replaced the coolant temp sensor ran the car and temp was fine took it for a ride around the block three times and temp got to just under red...coolant IS flowing...fan kickes on but not until about 240 degrees plus and that is when the needle is almost in the red. I am so confused and so frustrated...
If it doesn't, get a new t-stat.
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07-24-2009, 06:22 PM
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Ok I replaced the coolant temp sensor...at what temp should the fan kick in? Mine is coming on at around 230 degrees which is about 3/4 between half and red...is that too hot? Alson why is it that when I unplug the IAT sensor off the air cleaner jousing the fan automatically comes on and will shut back off when I plug it back in? What does IAT stand for anyway?
07-24-2009, 06:41 PM
#18
Ok I replaced the coolant temp sensor...at what temp should the fan kick in? Mine is coming on at around 230 degrees which is about 3/4 between half and red...is that too hot? Alson why is it that when I unplug the IAT sensor off the air cleaner jousing the fan automatically comes on and will shut back off when I plug it back in? What does IAT stand for anyway?
230 degrees is pretty damn hot. But don't go by the guage in the cluster, they're not at all accurate. I don't know much about LT1's but I would think your fans are supposed to come on around 215* of so.
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07-24-2009, 07:55 PM
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Ya it does seem hot...i guess we will see how it goes...Thanks again for the help guys I appreciate it! I just wish I could go a few days maybe even a week without having to do something else :-(
07-24-2009, 08:05 PM
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I just read "With factory programming, the PCM will command low speed fans (or primary fan) "ON" at 226º and "OFF" at 221º and high speed fans (or secondary fan) "ON" at 235º and "OFF" at 230º."