94 LT1-overheating, need help!!!
Thread Starter
Racer
Joined: Apr 2004
Posts: 482
Likes: 0
From: Wilmington NC
94 LT1-overheating, need help!!!
Hello all,
My 94 has the temp go to 235 rapidly in city traffic, and when it get to 245 I stop and let it cool down. Strangly, it has never boilled over and the aux fan never comes on. This has been going on for about a week and over a period of about a month I have noticed the gradual temp rise.
I have to get on the open road and drive 15-20 minutes at 55mph for the temps to start coming down, and after about 45 minutes it will be back down to 195.
The engine was replaced a year ago.
Yesterday I changed all the hoses, the thermostat, flushed the system, etc. I pulled the radiator and there was almost no trash in the fins and seemed to have no blockage. The water pump is working as it should. There was little trash in the space between the condenser and the radiator but not enough to interfere with the airflow. Could a small leak somewhere cause this to happen?
Any ideas? I'm to the point of replacing the radiator as I've replaced everything else.
Help!!!!!!!!!!
My 94 has the temp go to 235 rapidly in city traffic, and when it get to 245 I stop and let it cool down. Strangly, it has never boilled over and the aux fan never comes on. This has been going on for about a week and over a period of about a month I have noticed the gradual temp rise.
I have to get on the open road and drive 15-20 minutes at 55mph for the temps to start coming down, and after about 45 minutes it will be back down to 195.
The engine was replaced a year ago.
Yesterday I changed all the hoses, the thermostat, flushed the system, etc. I pulled the radiator and there was almost no trash in the fins and seemed to have no blockage. The water pump is working as it should. There was little trash in the space between the condenser and the radiator but not enough to interfere with the airflow. Could a small leak somewhere cause this to happen?
Any ideas? I'm to the point of replacing the radiator as I've replaced everything else.
Help!!!!!!!!!!
Burning Brakes
Joined: May 2006
Posts: 904
Likes: 0
From: Boynton Beach FL
Hello all,
My 94 has the temp go to 235 rapidly in city traffic, and when it get to 245 I stop and let it cool down. Strangly, it has never boilled over and the aux fan never comes on. This has been going on for about a week and over a period of about a month I have noticed the gradual temp rise.
I have to get on the open road and drive 15-20 minutes at 55mph for the temps to start coming down, and after about 45 minutes it will be back down to 195.
The engine was replaced a year ago.
Yesterday I changed all the hoses, the thermostat, flushed the system, etc. I pulled the radiator and there was almost no trash in the fins and seemed to have no blockage. The water pump is working as it should. There was little trash in the space between the condenser and the radiator but not enough to interfere with the airflow. Could a small leak somewhere cause this to happen?
Any ideas? I'm to the point of replacing the radiator as I've replaced everything else.
Help!!!!!!!!!!
My 94 has the temp go to 235 rapidly in city traffic, and when it get to 245 I stop and let it cool down. Strangly, it has never boilled over and the aux fan never comes on. This has been going on for about a week and over a period of about a month I have noticed the gradual temp rise.
I have to get on the open road and drive 15-20 minutes at 55mph for the temps to start coming down, and after about 45 minutes it will be back down to 195.
The engine was replaced a year ago.
Yesterday I changed all the hoses, the thermostat, flushed the system, etc. I pulled the radiator and there was almost no trash in the fins and seemed to have no blockage. The water pump is working as it should. There was little trash in the space between the condenser and the radiator but not enough to interfere with the airflow. Could a small leak somewhere cause this to happen?
Any ideas? I'm to the point of replacing the radiator as I've replaced everything else.
Help!!!!!!!!!!
Thread Starter
Racer
Joined: Apr 2004
Posts: 482
Likes: 0
From: Wilmington NC
I already installed a new cap and burped the system twice
I thought the temp sensor might be bad, it seems it would read wrong at all the ranges if it was but it's not.
This is all just very odd. I guess I'll go ahead and replace the radiator and if that doesn't help then I will bypass the heater core. It didn't seem blocked when I flushed the system but I guess it could be. Thoughts?
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
I already installed a new cap and burped the system twice
I thought the temp sensor might be bad, it seems it would read wrong at all the ranges if it was but it's not.
This is all just very odd. I guess I'll go ahead and replace the radiator and if that doesn't help then I will bypass the heater core. It didn't seem blocked when I flushed the system but I guess it could be. Thoughts?
I thought the temp sensor might be bad, it seems it would read wrong at all the ranges if it was but it's not.
This is all just very odd. I guess I'll go ahead and replace the radiator and if that doesn't help then I will bypass the heater core. It didn't seem blocked when I flushed the system but I guess it could be. Thoughts?
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 207
From: Orlando FL
If your cooling down when you drive 55 sounds like the cooling system (radiator, pump thermostat) is probably working OK. I can tell you that in traffic with outside temps over 90, it will get hot and keep getting hot if the aux fan does not come on. I believe that’s the cause of your problem.
Now you got to find out why the fan does not come on. Could be a bad fan, fan relay, connections at fan or relay, or PCM. I would check out those items first and look at the PCM last which is probably OK.
Also 12 volts has to be feed to the fan to come on hence it would be fused. Don’t have the fuse number or color or wires at relay connector but can give them to you tonight if needed.
Now you got to find out why the fan does not come on. Could be a bad fan, fan relay, connections at fan or relay, or PCM. I would check out those items first and look at the PCM last which is probably OK.
Also 12 volts has to be feed to the fan to come on hence it would be fused. Don’t have the fuse number or color or wires at relay connector but can give them to you tonight if needed.
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Race Director
Joined: Oct 2005
Posts: 11,776
Likes: 182
From: Rolla Missouri
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It should not take that long to cool back down when moving. Once you start moving, if it's not back down under 200 within just a minute or two, then something is not right. Sounds like the airflow through the system is being blocked.
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 207
From: Orlando FL
As I wrote my post, this bothered me also. It would depend on the outside temp but 45 minutes is to long. But the aux fan does need to work to get a true indication. Repair what’s known broke first then see how it reacts. Then I agree with the airflow check as described.
Pro
Joined: Feb 2004
Posts: 641
Likes: 16
From: O'Fallon MO
I just had this happen yesterday with my 91 L-98. There had been some maint requiring the left valve cover to be taken off. The wires to the EGR solinoid under the front of the intake plennum had been disconnected. The hot wire eventually shorted blowing the guages fuse which also sevices the fan control relays with power. As soon as the fuse was replaced it blew and we found the source of the short. Reconnected the plug and the fans are doing their job again. This was the first time I used the car since the maint had been performed.
