I've had the brittpart 180 factory thermostat get up to 215 in 96 degree and 100 percent humidity in central Alabama. That's why I went to the inline mod. Alex, you say seal the bleed hole on the thermostat, is that correct and if so may I as why?

 

I dont have reference with how much cooling the inline can offer but my factory with 180* seems sufficient enough with cooling. Our temperature in the East Coast goes over a hundred as well during summer but my recent install was much cooler running than the other I installed with the 180 thermostat. The original thermostat, I get 199* to 221*.

 

You may want to go to the 1st pic which is a pic of my truck as I did it. Stat close to the manifold and the petcock in the long section of tube. Put a paint can or similar under the pet **** section to raise the bleed point and use a spill free funnel kit if you want to make sure you get it all out. Make sure you do not have any sneaky leaks around the stat etc. Do not quit on this mod, it works. Check your Stant thermostat in water if all else is right.

 

I did check the thermostat in water n it is functioning properly. I'll have to get a new hose and redo it then but the fan shroud is not pressing on the fan or anything.

 

It takes more work to bleed than the standard set up for some reason. I had a few stubborn bubbles in my heater core and I had to resort to the funnel kit and got it all out.

 

will do. Been bleeding it like crazy trying to get it right. Hot and cold since I'll have the thermostat open when it's hot

 

temps here in Saint Louis Mo were in the 100's the last few days. I am running the factory setup with the 180 thermostat and seeing the same temps as you. With the AC on cruising the highway at 70-80 mph I am seeing temps from 197 to 208. My wife's suburban sits at about the same temps under the same conditions. I know, apples to chevy comparison. But I'm fairly comfortable with the factory setup and the 180 thermostat.

 

No that's a good comparison. I had an 08 Hummer H3 Alpha with the 5.3L V8, and it woud do 193-215F. I even had it go all the way to 237F after a very $$$$ Efan conversion kit failed to keep it as cool as the OEM fan clutch & fan blade. It was a good apples to apples comparison to our D2's as it had an ARB, a winch, small grill opening, small radiator, and an aluminum block V8.

I am happy with the OEM setup and the 180F with 50/50 coolant. I know if I ran a 60/40 ratio I'd probably lower the temps by 1-3F, but I just left it at 50/50.

My 05 Jeep would do 210-220F all the time, but it had a cast iron block so no worries about a liner slipping.

I say as long as you don't pass 215F you're fine. I had two new 03's back in the day before 180F thermostats, or Scanguage II's and I got well past 150k on the original head gaskets.

Most of the dead D2's I've dealt with were from broken throttle body heater plate lines, or the small line to the radiator & owners not keeping their coolant levels checked up on. Those little lines don't leave a big puddle & eventually when it's pumped out enough BOOM goes the temps, the head gaskets or a sleeve.

 

Crazy, hot and cold may be your problem. Needs to be filled/bled once while cold. It seems the general consensus is once mod done it's a PIA to get full/lbleed. What air is left will work it's way out as you do drive cycles and replenish the coolant.

Inline mod or normal D2 only/best to bleed when stone cold which means like park overnight. Get as much fluid as possible in during initial fill/bleed. Top off reservoir. take for drive bring up to temp, park until stone cold again like overnight. While still cold top off reservoir again. Do not ever remove the reservoir cap unless stone cold or in an emergency situation. Repeat drive and park cycles adding coolant to top off reservoir until it no longer needs additional coolant added. Even a properly filled/bled D2 should to be checked and coolant added daily until the system is air free.
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Twice in the last year I have gone to auto parts store and specifically asked for a 180 thermo for a big block chevy. Both times I got home and ran the part number. I keep getting 190 thermos. Dont trust anybody.