Hello I have a 01 5.9l ram 2 wheel drive. My issue is it heats up normally but then just starts slowly getting hotter and hotter up to around 240f~ if I turn my heater on full blast it will keep it at or under 210f~ I've replaced the tstat twice first one was a fail safe and because it got over 212f it failed safely and stayed open. The new tstat is a 196f, the radiator is only 2 years old purchased from the dealership.
I have tried the basic tricks to see if fan clutch is bad ( it stops spinning right as engine turns off, it's not leaking any grease, there is still tension when moving fan with hand after engine is heated up, it's not wobbly)

The water is obviously moving through the system since the heater air I can't even hold my hand over the vent it's so hot.

There's no obstructions infront of the radiator.
Anyone have any idea what I should try? It's getting hot I live in AZ and having heater on full blast isn't fun...

Thanks for your time
Tony

 

Have you done any work on the system recently. If so and even if not you may have air in the system. I would start by burping. This takes a while but it could be the issue.

 

Water Pump????

 

I do hear bubbles flowing through the heater core for a few seconds when I first start it up... How high do I have to get that passenger side up to burp the system completely?

 

if you are jacking up ONLY the passenger side, that will TRAP air.

Jack the whole front end up enough for BOTH WHEELS to be about 3 inches off the ground. Or buy those little ramps for you to drive up when doing an oil change and such. While you are at it. Drain ALL COOLANT from the rad, refill with water and Napa coolant flush with descaler. Let the truck run for 30 mins. Then refill with 50/50 water antifreeze.

 

Make the bottom of the radiator filler neck the highest point in the system, above even the top of the upper radiator hose, and keep it there until you've seen the thermostat operate at least twice. If after that your coolant is apparently full and the engine overheats, you've got blockage somewhere.

 

I had a problem just like this years ago and it turned out to be the "anti-collapse" spring in the upper radiator hose - it had dislodged itself somehow from the hose and gone into the radiator where it compressed and created a "tube" inside the radiator that caused a partial blockage. A new upper radiator hose completely fixed the problem.

Chuck

 

Thanks guys I'll try burping the system tomorrow and see how that goes and post back.

Thanks
Tony

 

New update.... I don't have a jack because I'm poor so I drove up on some 4x4 posts that I had laying around and spent 25-30min burping system got some air out. Now it still overheats and now I'm getting a P0303 error code.... Oh yay miss fires again... Any ideas?

Thanks
Tony

 

I know I'm probably out in left field here but you have got me scratching my head. Water pump possibly or an obstruction. When the engine is warm check to see if the rad hoses have colapsed. As for the misfire on cyl three pull the plug and see what it looks like. I had an old mazda mpv that had a bad head gasket the leaked into the cyl and it would burn coolant. Enough to cause a misfire but you could smell the coolant in the exhaust. The van would overheat because the coolant system wouldn't pressurize and that affected the flow. I truly don't think you have this problem but have seen stranger things. I would go pump or obstruction for the OH issue.