L2500dt

[bill10mm]

My 1999 l2500dt overheats with rpm at pto set speed. Replaced entire cooling system. No change. Put water bottle on overflow tube. No bubbles or Antifreeze. I'm at a loss. Can pull down below 2000 rpm and will cool down. Run up to 2500 and heats up

 

[North Idaho Wolfman]

Is the fan on the right direction, and is it the right fan?
I've seen so many that had either the wrong fan or fan was installed backwards and wasn't pulling enough air.
Also loose or slipping fan belt.

If you've truly replaced all of the cooling system and you still have an issue, then it's either a cracked head or blown head gasket.

Fill the radiator full and with the cap off run it and look for bubbles.

 

[bill10mm]

Is the fan on the right direction, and is it the right fan?
I've seen so many that had either the wrong fan or fan was installed backwards and wasn't pulling enough air.
Also loose or slipping fan belt.

If you've truly replaced all of the cooling system and you still have an issue, then it's either a cracked head or blown head gasket.

Fill the radiator full and with the cap off run it and look for bubbles.

Fan only goes on one way, won't fit backwards. Have put bottle on overflow line. Cap doesn't leak and no bubbles

 

[Astr]

My 1999 l2500dt overheats with rpm at pto set speed. Replaced entire cooling system. No change. Put water bottle on overflow tube. No bubbles or Antifreeze. I'm at a loss. Can pull down below 2000 rpm and will cool down. Run up to 2500 and heats up

Fan belt slipping at high RPM? Or the radiator screen is caked in chaff. Check the cheap stuff before tearing into the block.

 

[TheOldHokie]

My 1999 l2500dt overheats with rpm at pto set speed. Replaced entire cooling system. No change. Put water bottle on overflow tube. No bubbles or Antifreeze. I'm at a loss. Can pull down below 2000 rpm and will cool down. Run up to 2500 and heats up

What does it do when hot? Does it boil over?

Dan