Hi everyone -- here's an ongoing problem I've been having with temperatures; it seems like a constant battle. I've read up on a lot of threads about overheating, but I feel like I've done just about everything I've seen advised and still no real improvements. My truck is currently running between 200-220, which is definitely way too hot. The work thus far has been:

Two new head gaskets and one cylinder head resurfaced
New radiator
New water pump
New thermostat (180 degree)
New overflow bottle
New t-fitting
New heater core hoses
New heavy-duty fan clutch

Now, I feel like it's worth mentioning that the head gaskets were done most recently (last week) and the truck is actually running hotter since that work. Previously it was averaging 195-210, with it only hitting 220 in standstill traffic on hot days. Which was still too hot obviously, but now the truck is averaging about 200-205 on the highway and 215-220 around town. It hasn't been hot out so I have no idea how it will perform when the ambient temps go up (not well, I imagine).

I know there's air in the system and I'm going to try and get it out (I hear the waterfall noise behind the dash), but would air bubbles cause this kind of temperature fluctuation alone? Could the heater core be the culprit? My heat seems to work fine. Any help would be appreciated.

 

90% chance your thermostat is defective. Here is how to test for sure cheaply. Advance and Autozone sell a hose repair kit with a gray plastic bushing - put that in place of the thermostat between the lower radiator hose and the hose going to the plastic Y. Take the top radiator hose and route it directly to the intake manifold pipe. If I am right, you should consider the bypass thermostat mod.

 

Where did you get the tstat from ?? When in doubt get the warm weather tstat from Atlantic British. Has never let me down

 

Those are stock temperatures. You are reading on here about people who have changed to a cooler opening T stat which along with a proper bleed lowers operating temps.

Due to emissions regulations the factory operating temps were up to 220F so what you report is normal.

Not optimal but normal.

And certainly not "way too hot."

Just that you can do better.

180 degree thermostat and a proper bleed is what you need.