ls1 over heating
Thread Starter
Staging Lane
Joined: May 2016
Posts: 54
Likes: 0
ls1 over heating 
Ok, So I noticed my third gen swapped Ls1 overheating in traffic to nearly 260 degrees, and my temp gauge wouldn't even work until the car got to over 200 so degrees. I take the car home and change out the thermostat/ and changed the radiator fluid and it didn't even read the temp at the gauge after seeing if that would fix it. I took the cap off to bleed the system after letting run for about 20 mins while adding water I still had no reading on temp gauge. I changed the coolant sensor and the connector to sensor NOW my gauge works but my car is overheating very fast now. I drove it about a mile and it got over 260.
Also, when I changed the radiator fluid I didnt drain it from the engine plugs..
thank you in advance if anyone can help me.. I'm thinking its the water pump now..
Last edited by Tanmanls1; Aug 24, 2016 at 02:36 PM.
Thread Starter
Staging Lane
Joined: May 2016
Posts: 54
Likes: 0
ls1 over heating Ok, So I noticed my third gen swapped Ls1 overheating in traffic to nearly 260 degrees, and my temp gauge wouldn't even work until the car got to over 200 so degrees. I take the car home and change out the thermostat/ and changed the radiator fluid and it didn't even read the temp at the gauge after seeing if that would fix it. I took the cap off to bleed the system after letting run for about 20 mins while adding water I still had no reading on temp gauge. I changed the coolant sensor and the connector to sensor NOW my gauge works but my car is overheating very fast now. I drove it about a mile and it got over 260.
Also, when I changed the radiator fluid I didnt drain it from the engine plugs..
thank you in advance if anyone can help me.. I'm thinking its the water pump now..
Also, when I changed the radiator fluid I didnt drain it from the engine plugs..
thank you in advance if anyone can help me.. I'm thinking its the water pump now..
Last edited by Tanmanls1; Aug 23, 2016 at 07:23 PM.
Thread Starter
Staging Lane
Joined: May 2016
Posts: 54
Likes: 0
ls1 over heating Ok, So I noticed my third gen swapped Ls1 overheating in traffic to nearly 260 degrees, and my temp gauge wouldn't even work until the car got to over 200 so degrees. I take the car home and change out the thermostat/ and changed the radiator fluid and it didn't even read the temp at the gauge after seeing if that would fix it. I took the cap off to bleed the system after letting run for about 20 mins while adding water I still had no reading on temp gauge. I changed the coolant sensor and the connector to sensor NOW my gauge works but my car is overheating very fast now. I drove it about a mile and it got over 260. 
Also, when I changed the radiator fluid I didnt drain it from the engine plugs..
thank you in advance if anyone can help me.. I'm thinking its the water pump now..
Also, when I changed the radiator fluid I didnt drain it from the engine plugs..
thank you in advance if anyone can help me.. I'm thinking its the water pump now..
Last edited by Tanmanls1; Aug 23, 2016 at 07:22 PM.
TECH Resident
Joined: Apr 2010
Posts: 926
Likes: 18
From: Central Texas
Find a place where you can get the front of your car raised until the radiator is the highest point. Fill and walk away, come back in a coupla hours leaving the radiator cap off. Repeat until it will no longer take water(coolant) you should now have all the air out of the system and it should function correctly. Most F- bodies are a PITA to get the air out of the system
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Are you using the steam ports in the heads or did you block them? If using them where did yiu plumb them to? Hopefully you just dont have it blead good enough yet. I always have the front end jacked up as high as i can get it when primimg/bleeding the cooling system. Run it through a heat cycle on the jack stand top it back off and should be good to go.
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They are on the intake side of the heads on front and back corners down by the valley cover. Some older motors had all 4 corners tied together and a 1/4" line then run to radiator, all newer motors just have the front 2 corners tied together. On a swap people do all kinds of stuff youll have to get in there and look to see if they even put the steam line on. Google image search will show you what your looking for as far as the steam ports.
TECH Resident
Joined: Mar 2012
Posts: 821
Likes: 4
From: Elkridge MD
Third Gen what? All these old cars have several generations. Are you talking about a Firebird/Camaro? They are notorious for having no airflow. You MUST run a fan shroud, and you MUST have the little ugly spoiler intact under the bumper.
I had an '84 TA, and the 350 I built for it got up to 240+ until I figured out I needed those.
I had an '84 TA, and the 350 I built for it got up to 240+ until I figured out I needed those.
Thread Starter
Staging Lane
Joined: May 2016
Posts: 54
Likes: 0
Third Gen what? All these old cars have several generations. Are you talking about a Firebird/Camaro? They are notorious for having no airflow. You MUST run a fan shroud, and you MUST have the little ugly spoiler intact under the bumper.
I had an '84 TA, and the 350 I built for it got up to 240+ until I figured out I needed those.
I had an '84 TA, and the 350 I built for it got up to 240+ until I figured out I needed those.
Thread Starter
Staging Lane
Joined: May 2016
Posts: 54
Likes: 0
They are on the intake side of the heads on front and back corners down by the valley cover. Some older motors had all 4 corners tied together and a 1/4" line then run to radiator, all newer motors just have the front 2 corners tied together. On a swap people do all kinds of stuff youll have to get in there and look to see if they even put the steam line on. Google image search will show you what your looking for as far as the steam ports.
Thread Starter
Staging Lane
Joined: May 2016
Posts: 54
Likes: 0
Ok I tried this.. I let it run for about 5 mins and the car got to about 240 and it didnt burp so I just shut it off. The coolant level is stayed the same.