94 LT1 Running Hot
Thread Starter
Le Mans Master
Joined: Dec 2002
Posts: 5,135
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From: Harbeson DE
Cruise-In IV Veteran
St. Jude Supporter
94 LT1 Running Hot
My 94 LT1 is running hot at 225 with out the A/C on. When the A/C is on the temp rises to 250. :eek:
Suggestions.......
Suggestions.......
Race Director
Joined: Oct 2002
Posts: 13,717
Likes: 5
From: RI
Re: 94 LT1 Running Hot (Opium)
Air in coolant? Coolant level topped off.........? Check for crap in the radiator like bags, leaves, trapped debris. Thermostat stuck closed. Low oil level, dead oil pump. Fans not coming on? Do you have a service engine light?.........codes of light?
Let us know..........
Kitt
Let us know..........
Kitt
Melting Slicks
Joined: May 2001
Posts: 2,143
Likes: 7
From: San Diego CA
Re: 94 LT1 Running Hot (Opium)
:iagree:
Be sure the fans are working. At 250 both should be running.
Another thought, the fans are controlled by the A/C condensor pressure with the AC on. You might be low on freon to the point where there isn't enough pressure to turn them on. But at 250 AC or no, both fans should be blowing 40MPH worth of air.
It is virutally impossible to see if the radiator is clogged, but you can get a hint if you look at the radiator shroud from the passenger side. There is a space about 1 1/2" wide to look across the radiator. If you see any debris, it's time to pull it and clean it.
When the engine is cold, pull the cap on the expansion tank (not overflow). Start the engine, if the expansion tank is not completely full (it should be pretty close) do you see a steady stream of coolant squirting into the tank. If not the impeller may be gone.
You might replace the t-stat, if its frozen you could be in for hi-temps.
Be sure the fans are working. At 250 both should be running.
Another thought, the fans are controlled by the A/C condensor pressure with the AC on. You might be low on freon to the point where there isn't enough pressure to turn them on. But at 250 AC or no, both fans should be blowing 40MPH worth of air.
It is virutally impossible to see if the radiator is clogged, but you can get a hint if you look at the radiator shroud from the passenger side. There is a space about 1 1/2" wide to look across the radiator. If you see any debris, it's time to pull it and clean it.
When the engine is cold, pull the cap on the expansion tank (not overflow). Start the engine, if the expansion tank is not completely full (it should be pretty close) do you see a steady stream of coolant squirting into the tank. If not the impeller may be gone.
You might replace the t-stat, if its frozen you could be in for hi-temps.
Thread Starter
Le Mans Master
Joined: Dec 2002
Posts: 5,135
Likes: 0
From: Harbeson DE
Cruise-In IV Veteran
St. Jude Supporter
Re: 94 LT1 Running Hot (Opium)
I checked the coolant and it seems to be fine. It appears that I do have some debris blocking the radiator.
Will get that cleaned out and see what happens.
Thank you everyone for your input. :hat
Will get that cleaned out and see what happens.
Thank you everyone for your input. :hat
Team Owner
Joined: Sep 2001
Posts: 62,139
Likes: 1,728
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: 94 LT1 Running Hot (Opium)
1. Clean the front of the radiator thoroughly, the only good way to get it all out is by removing the thing and getting all the junk from between the fins.
2. Flush the entire system and refill. Remember to burp the system so all the air comes out.
3. Whether you change to a 160 thermo is up to you, you already have a 180 and its ok, but you should think seriously about a fan switch wired to the main fan or having your PCM reprogrammed to make them come on sooner.
4. Add a bottle of Water Wetter, sometimes you can get 5-10 degree difference from this stuff.
2. Flush the entire system and refill. Remember to burp the system so all the air comes out.
3. Whether you change to a 160 thermo is up to you, you already have a 180 and its ok, but you should think seriously about a fan switch wired to the main fan or having your PCM reprogrammed to make them come on sooner.
4. Add a bottle of Water Wetter, sometimes you can get 5-10 degree difference from this stuff.
