Tanmanls1

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..

Tanmanls1

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..

Tanmanls1

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..

cookseyb

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

NowhereFast

I like to fill these through the upper radiator hose, and then top off the rad after. Seems to make **** a lot easier.

cookseyb

That works too, wasn't sure about where he was trying to work on it at.

gametech

iTrader: (1)

Have you verified the temps with a real gauge of any sort? I doubt the readings you are getting.

tug686spd

iTrader: (11)

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.

joecar

+1 bleed air out thru the steam ports.

Tanmanls1

No I have not, How can I do that?

Tanmanls1

Thanks for the replies. Where are the steam ports? Sorry the dumb question. My first ls1 I'm learning though. I'm young and I bought this off craigslist I didn't do the swap my self..

Tanmanls1

Thank you for the replies!

tug686spd

iTrader: (11)

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.

gametech

iTrader: (1)

The simplest way would be to point a infrared thermometer at your radiator. There are an unlimited number of slightly more difficult or dangerous ways to do it.

superdave84

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.

Tanmanls1

89 rs

Tanmanls1

i found the steam ports how exactly do I bleed them?

Darth_V8r

iTrader: (4)

Lift the front as high as you can, take the cap off, run the car. When it burps, top it off and cap it.

You'll recognize the burp when it happens

Tanmanls1

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.

Tanmanls1

Also my fan turns on as soon as I start the car