if its a 180 deg Tstat, then the coolant temp is too hot.


So the operating temp is around the same with any Tstat that you have used? I would hate to recommend a new radiator but I there isn't much left in the system in regards to temp regulation. Once you get the IR therm and get some readings you will have a better idea if this is the issue. The bottom of the radiator will be much cooler than the upper region. I would get a reading upon reaching the destination. Then let the truck cool down and start over when temps will be under Tstat opening temp. Get several different readings at idle until temp stabilizes around 200, drive it for a few minutes and get another reading.

 

opened bleeder (sounded like air escaping before coolant flow, no bubbles), topped off expansion tank, same test drive scenario, 188.6 for 3 miles, 194 for a mile then leveled out at 197.7 for the duration, climbing up to 199 last half mile... hmmm maybe I didn't fully bleed? still waiting to hear from a friend to borrow IR thermo to test radiator, but seem to be moving in a positive direction?

 

Where did you find Rotella in 20w50???

 

my bad... rotella T 15-40. was going from memory (and I'm not as young as I used to be)

 

No worries!! I wish they did make a Rotella 20w50!!!

 

That's a lot of air left over. my engine is now running the coolest it ever has and I purged with the tank up on the battery, cap off, idle for 45 min, drive around with cap still off/loose and there was nearly zero air left over. I've done it as listed in Rave a half-dozen times but I don't think that you get all of the air out with that method and operating temps will always be higher than they should be.

 

Brilliant Chubbs! I feel like I'm headed in the right direction and will try your method in the morning.

 

Never use Barrs leak.

I grew up in a radiator shop. Seen the havoc it creates. It's good to get you home, but not longevity.

 

I dont even use that method anymore.

I park my truck on a steep hill, steep is the key, and bleed it that way.

 

might have to drive it up on the curb stop then... gotta love living on an island 3 feet above sea level (actually, it's brilliant living on an island 3 feet above sea level, but you get the idea) I'm also inclined (pardon the pun) to find the leak(s) (pretty sure I already have) instead of trying to plug the leak... not loosing any coolant now, just running a bit warm based on what I've read here. No point in continuing to bleed right now, as I have a hairline crack in the bleeder nipple (looks like somebody got over zealous tightening it down) and I can squeeze the hose, see it leaking coolant and hear it sucking air when I release pressure. Just ordered a whole new upper hose set. Thanks Amazon, I'll be back at it tomorrow afternoon.