Lt1 rapid overheat after head gasket change
#1
Lt1 rapid overheat after head gasket change
Hello all, I just joined the forum hoping for some help. I change my head gaskets on my lt1. Previous owner cooked the heads so I had them milled. New thermostat. Now on my first start up while trying to follow the instruction I found and read many post on this fourm the car sky rockets to the red line. Maybe in 2 minutes. The coolant in the radiator isn't hot I can put my fingers in it and not get burnt. The temp gauge sending unit is new as well. I know it's probably air but how I can get the air out if I only have 2 minutes or so before it hits the red. Also I've tried about 4 times now. Thank you all.
#2
Re: Lt1 rapid overheat after head gasket change
Hello all, I just joined the forum hoping for some help. I change my head gaskets on my lt1. Previous owner cooked the heads so I had them milled. New thermostat. Now on my first start up while trying to follow the instruction I found and read many post on this fourm the car sky rockets to the red line. Maybe in 2 minutes. The coolant in the radiator isn't hot I can put my fingers in it and not get burnt. The temp gauge sending unit is new as well. I know it's probably air but how I can get the air out if I only have 2 minutes or so before it hits the red. Also I've tried about 4 times now. Thank you all.
#4
Re: Lt1 rapid overheat after head gasket change
Based on your description, it is almost always air in the system. Use the fill procedure on my tech page.
#5
Re: Lt1 rapid overheat after head gasket change
Thanks I've followed it I have a large amount of bubbles coming out of the radiator cap then the temp heads to the red zone. Do I just keep repeating? I've tried w/o the thermostat to no avail same result
#6
Re: Lt1 rapid overheat after head gasket change
Well verified the pump is working. It seems I can't run long enough for the thermostats to open so the radiator remains cool thus the fans do not turn on but the gauge is red. How can I bleed the system if I cannot run it long enough to get the thermostat open and remove the air pockets..?
#7
Re: Lt1 rapid overheat after head gasket change
How did you determine the water pump is working?
And you followed Shoebox's procedure EXACTLY?
Hate to mention it, but..... leaking head gasket?
And you followed Shoebox's procedure EXACTLY?
Hate to mention it, but..... leaking head gasket?
#9
Re: Lt1 rapid overheat after head gasket change
Well verified the pump is working. It seems I can't run long enough for the thermostats to open so the radiator remains cool thus the fans do not turn on but the gauge is red. How can I bleed the system if I cannot run it long enough to get the thermostat open and remove the air pockets..?
#10
Re: Lt1 rapid overheat after head gasket change
I do have a temp gun I'll take some temps. I suspect it is steam pockets as it isn't boiling and the heat just begins to get warm as it hits the red. The engine doesn't feel like a super hot engine. What temps shot on the sides of the head would be in the range of operating temp? 215 ish? Thanks for the help it's kinda got me stumped!
#11
Re: Lt1 rapid overheat after head gasket change
Ok I have some data temp gauge in car reads near red. IR temp gun reads 110 on the sending unit and around it. ohm'd the sending unit and got a measurement of 48.5 ohms I don't know what the reference is for ohms/degrees but I believe the ohms correlate to the measurement on the gauge i.e. Lower ohm higher reading in degrees on the gauge. Either way surface temp seems way low for what the gauge says.
#12
Re: Lt1 rapid overheat after head gasket change
#13
Re: Lt1 rapid overheat after head gasket change
Bad sensor? I snapped the plastic bit off the original one removing my manifold.. This is not an ac delco sensor it's a Orileys whatever it's new so maybe defective?