ok i had a post on here earlier and im need some help making a decision and getting ideas, my truck is running hot, i gone through a put on a large cooling fan to replace the old mechanical (the big one from advance) and replaced the water pump, and thermostat and 13lb rad cap. The truck runs while drivign down the road and stays between N and O if not below that! but if i stop and pop the hood the overflow tank becomes completely full and overflows a bit but its not overheating then. then if i let the truck sit still and run after a while it will start to get too hot and get up to M if not higher. Any ideas whats going on? Is the cooling fan i have not enough? or what?

 

Fan - electrical or mechanical? If mechanical, is the fan shroud still in place? A big fan doesn't mean much if it's not pulling the air through the radiator. This is my primary suspicion since you mention that the engine runs Normal going on the road where the fan doesn't play as big of a part in the cooling.

Also, is the blade pitch of the new blade in the same direction as the old? Just want to be sure that the blades are pulling air and not pushing.

To a lesser extent - is the radiator clear of obstructions - both inside and out? Bug and road debris, as well as internal crud, wreak havoc on the heat transfer.

Overflow tank - wondering if the cap is correct for the truck, or perhaps maybe there is a problem with the radiator tank lip, preventing a good seal.

Wouldn't be too concerned about getting up to 'M', particularly if it's a hot day and the A/C is running - however, beyond 'M' would be of concern, no matter what.

Good luck, and keep us posted on your findings.

 

no its electric, just 1 big electric, just replaced the cap, just hopeing tis not the head gasket, i have no indicators of it being blown though, im thinking that maybe the 1 fan isnt enough, im thinking of putting 2 smaller ones on to pushtrough so i get better rad coverage and maybe puttting the big on so it pulls in the center, i know everything is working as it should, i dont even see any bubbles in the rad either when running, it just seems to want to push the coolant out. maybe the rad is too plugged i dunno

 

What do you have the overflow tank at, mine will occasionally run up to the a when pulling hard during the summer. My tank fill from the full cold to within 1/4 inch of the top during summer when up to temp.
I also have the supercool setup complete with the larger radiator and the large external transmission cooler.

 

see heres the weird thing, i can leave the tank empty and fill the rad and it will end up overfilling the overflow and leaving the rad low what does that mean?

 

I guess we never figured this one out. Any ideas I am having a similar issue.

 

He never did post which e-fan he had...I have a Mark8 e-fan on my truck and have no problems whatsoever with cooling. I did however have a problem before this which was extremely similar.....my original radiator was extremely clogged causing all this.....the 4 core I have now has NO issues.....I'd be willing to bet a radiator clog is the OP's problem.....what is your truck doing?

 

Possible head gasket.