running hot need some input

[rccktmn2]

Just a thought, did you point the temp gun at the thermostat housing, before the housing on the coolant passage of the intake and on the upper radiator hose? If there is a temp difference in that area I would say thermostat, what temp was the thermostat you put in? If it's 190-195 your engine will run a little hotter than normal, try a 160 or 180. The clutch fan doesn't work past 35 mph, it's designed to cool the engine at low rpm's, so if you get up to highway speeds and the engine is cooling down to whatever the temp of the thermostat is that you put in but at idle or in traffic in town conditions it heats up to 220 then I would start looking at the clutch fan. The black air dam should be there on this year and it does help a lot so if you don't have one I would start looking to get one or you could always upgrade to electric fans and a shroud. Also did you check the radiator cap? If your cap does not let pressure build up in the system then there will be no coolant flow to the back cylinders of the block and cause overheating issues as well. Good Luck.

 

[olds307 and 403]

The 307 is an easy motor to cool. A failing thermostat will cause half the rad to be cool and start blowing out the cap. Make sure you have proper coolant flow and air movement. How is your fan shroud? I have the Champion 3 core, cools OK. I was thinking the Griffin dominator series when I upgrade the motor.

 

[ERIC87442]

The radiator is a gm radiator he worked at a gm dealership and replaced it with everything gm. I did notice a difference between the hose and the intake the hose was around 198 and the intake was 220 230 ish. The air damn is there it use to be it would heat up on the highway when it was hot out. Last night it got hot in town.

 

[ERIC87442]

I replaced the radiator cap and drove for about 30 min up and down the highway then in town for a bit. No issues. It ran about 10 15 degrees hotter down the highway 195-200 and cooled to about 180-190 in town. But the real test will be when its real hot out again

 

[454muscle]

have you removed the rad cap to see what flow you have thru the rad. I once got a rebuilt pump that had the wrong impeller so it wasn't moving the coolant and the car ran hot

X2. Remove the rad cap, start the car and let it warm up (with cap off). Look in the rad cap and see if the water starts to flow when it's warmed up. If it doesn't flow and just bubbles up then your thermostat is not open. If it starts to flow then begin to look at other possibilities.

 

[DoubleV]

Timing set to specs?

 

[DRIVEN]

Just out of curiosity, have you tried to run it with no thermostat at all? I wouldn't leave it that way but it only costs you the price of a gasket to try it temporarily.

 

[ERIC87442]

Timming should be right if my guns right. I set my gun to 20 and aim it on 0.i just adjusted it a bit it was probably 1/2 degree retarded. (Was heating up before i did that) i did it for another reason, at idle in park it has kind of a rythmic pop through the tail pipes but not all the time

 

[DRIVEN]

I went back and reread the thread. Just so we're clear, this started BEFORE the engine was rebuilt? After the rebuild the problem remains but is getting worse? If so, I would not suspect anything that was replaced at the time of rebuild. What was reused?

 

[ERIC87442]

Radiator,upper and lower hoses, heater core, waterpump. All not replaced by me. All been replaced once though