3406 high coolant temps

@rank there’s a kit you can buy, you put the end of the overflow hose in it, and it’s supposed to change colors if combustion gasses are present. I’ve never used one myself, but it may be something to look into if you’re concerned about that.

When mine starts running warm, it’s always dirt and crud plugging up the fins on the radiator. A little time with an air hose and she’s good to go again.

 

Firing rings are basically head gasket issues iirc. Are you having other symptoms that point to a head gasket problem? How hot is hot?

 

Take a bottle of water and run your over flow hose into it. With it warned up good and rev the engine to about 1500 see if it bubbles. If not rig up an extension on the hose and tie it to mirror or hold it what ever suits you and go for a drive loaded don't be easy make it run full boost. You didn't say it was loosing coolant so I wouldn't think you have issues there.

That bleed hose from front of head to top radiator tank if it's restricted it will get warm and mirror a head gasket or liner issue sometimes.


Oil cooler passages are notorious for stopping up and restricting flow.

Thermostat housings will erode internally and cause issues but you woulda seen that already.


Also check just to be sure the fan is pulling air from outside the radiator. With hood up RPM at 1000 fan engaged throw a dry wash cloth up toward the radiator front. It should pull it and hold it there. I have seen more than one backwards fan blade.


When you done the pump did you notice if it had a metal or plastic impeller. New backing plate?

 

Kind of a dumb question but have you verified the guage is accurate? Hows the oil temp? It should be somewhat close

 

What's your pyro reading when it heats up?

 

That makes it sound like a boost leak or lack of air problem