New LS3 start up but no water flow through radiator
 

Finally got my LS3 427 started but the water is not flowing through the block. All parts are new to include the thermostat and a Dewitt radiator. Temp rises but radiator is cold. This is the first few starts, so I only run it for a minute or so since the engine temp rises. First thing I think of is the thermostat but I remember seeing posts about getting the water to initially flow. thanks

Answered your other post. How hot are you allowing it to get while running? I bet not enough to get the t-stat to open

Are the fans turning on?

Don

Fans are not going because they are tied to the thermostat in the radiator. I remember this some where else so I will try this.

17. We are not ready to fill the system just yet, as you may have noticed there is no intake manifold on the engine. We will give you an update once we get the car running. Be Cool has very detailed instructions on how to properly fill the system and its too detailed to fully explain here, but here are a few things to note. Jack up the nose so the radiator is the highest point in the cooling system. Fill the radiator with the engine off. Wire the fans to run all the time, and if so equipped turn the heater on high. Then start the motor with the radiator cap installed in the loose position. Run the vehicle until the thermostat opens. When the fluid suddenly drops in the radiator, add an additional 2-3 quarts. You may need to repeat this cycle, but once topped off the second time tighten the cap. After a few heat cycles check the level one more time and you should be good.


Sources



Be Cool
Essexville, MI 48732
800-691-2667
»www.becool.com

A dewitt radiator has the fan trigger in the radiator, so unless it's flowing through the radiator, they won't turn on.

Coolant doesn't flow through the radiator until the t stat opens. If you temperature gauge isn't exceeding your t sat opening temp, you aren't running it long enough.

yup i freaked out as well. I need up putting about 3 jugs in to finally fill everything up. Just go buy a cheap temp infrared gauge and point it to the thermostat. My guess is you dont have it hot enough yet

Thanks but temp in going past 210 to 240.

I wouldn't let it go that hot again. The infrared gun aimed at the tstat will give you an indication of a faulty gauge. If gauge is ok, you have a bad stat, or some kind of blockage, ie a shipping plug left on radiator inlet, etc.
Is the TStat a GM piece? It should open, and you should see water moving in radiator before 210. If not, shut it off.

Air pocket if it goes from 210 to 240 quickly.