Engine overheating

[meanchicken]

If the fan is kicking on at 180 and off at 172, then why would it be the stat?
The stat does not tell the fan when to turn on and off.

The fan kicks on when the chip in the ECM tells it to...correct?

Who's chip are you using and what temp is it burned to turn the fan on at??

 

[Dabigguy]

The fan is kicking on it'll get up over 200 if I let it, been cutting it off once it gets to 200, ambient temp is about 66 degrees.

Wouldn't this lead us to the stat being the problem MeanChicken?

 

[TR Custom Parts]

Are you just letting it sit in the driveway running?? If so, put some miles on it and see what happens.

 

[meanchicken]

Checked it again with it just idling it gets up to 180 and the fan kicks on and cools it to about 172 shuts down then does it all over again. If the thermostat was opening I should be able to feel something moving through the upper radiator hose correct?

Wouldn't this lead us to the stat being the problem MeanChicken?

I was reading his second post above.
The above describes normal fan operation if the chip is programmed to kick the fan on at 180.

The t-stat does not tell the fan when to turn on, the ECM chip does.

 

[mikestertwo]

I was reading his second post above.
The above describes normal fan operation if the chip is programmed to kick the fan on at 180.

The t-stat does not tell the fan when to turn on, the ECM chip does.

I agree. It sounds like it is operating normally. Take it out and drive it and see what the temps are.

 

[Hacksaw]

This also might sound dumb, but is the lower radiator hose OK? They get soft, then collapse some during to the water pump suction.

 

[meanchicken]

This also might sound dumb, but is the lower radiator hose OK? They get soft, then collapse some during to the water pump suction.

That's actually a pretty good point to check in overheating systems.
Old radiator hoses can act like check valves.

...but...if the secondary description posted that the fan clicks on at 180 and off at 172 is accurate, I still think his chip might be burned for this state in normal operation.

Needs to drive it around a bit and post back the behavior.