Ok. Where do I start....I have had 3 OEM genuine grey 180 thermostats over the past year. One I had to warranty because it was running 200-210. The others ran 194-199 driving, and up to 208-212 at long idle in 80-90 degree weather. Shane, if you are reading this, the system was bled properly each time. Lol. Parked on a steep hill, raised the reservoir, top off cold through bleed screw over the next week or so. No air in the system. My whole cooling system is new. Well boys and girls, I installed a Britpart black 180 thermostat (marked 78c inside) about a week ago. Coolant temps have dropped 6-8 degrees across the board. In 90 degree temps, I am now seeing 185-195 driving and only 201-206 at long idle. I have lower temps now than the genuine 180 did in 60-70 degree weather. I truly believe that there have been bad genuine 180 stats out there lately. The ones I had ran like they were 195 stats or didn't have the soft spring, thus needing higher rpm coolant flow to fully open. None failed mind you, just ran higher than they should, especially at idle and higher loads. My genuine grey now rides in the back of my truck as a spare. Britpart stat with the 78c inside and two large metering holes versus four small on the genuine is the way to go. I'm sold. My temps are now what I consider perfect. 185-195 driving, maybe 199-203 uphill with high load, and 206 has been my highest idle. Before at idle at red lights, I was at 208-210 dropping fast to 195 once going. Now, same lights 195-201 for the most part. I'm really digging the Britpart stat!

 

I hate to admit it but BritPart has come a long way

 

Yep I switched from OEM gret thermostats to the Britpart units & haven’t had a single issue..

 

So you kept it so I can try it?

 

 

I find it very...silly...for someone to say...

There's no air in their system.

Did you shrink down and go scuba diving through your hoses? How did you get past the inpellar on the water pump it didnt cut you to bits? While you're in there did you check your sleeves for any leaking?

Air pockets can exist even after you do all these things.

Truth is, you dont know. You keep working it till it gets down to what's acceptable.
When you change stats the reason the third or fiftieth one works is because you got lucky and the air came out because you were messing with it all that time.

Just because you do it "the book method" which is meh, or do it on a hill, which is better imo, doesnt mean you got it all.

Maybe I should start selling tstats since I always manage to get them to run in the "normal" range.

 

Shane, the system was bled each time. Might there have been two microscopic air bubbles, sure. Point is the Britpart runs lower temps across the board. I'd be glad to send you the stat. It very well might run cooler in YOUR truck. In mine, it did not. Many other variables in the heat produced...climate, new or rebuilt motor, cam or not, plug condition, coolant type and ratio. I never said the stat didn't work. As a matter of fact, I'll be the first to admit that I could have kept that stat in the truck for years. Anything under 210 is absolutely fine, especially on a Turner motor with tophats. My point was the Britpart runs cooler. Period. How about I send you my grey one, a new Britpart, and you try both? Will you come back here and apologize to everyone when the Britpart runs cooler? As for running in "normal range," the old stat did. Again, I did not like seeing 208-210 idle temps more often than not. That is still within the "normal range." I did not pull stats three in a row, back to back. This was over the last year or so. Shane, why do you think you are the only one who knows how to bleed these trucks? Not everybody that complains about the OEM 180 stats lately says they have failed. Many are running at higher temps than they should be. Shane, where are you located? What are your outside temps right now?

 

Hahaha

This is all very interesting, I have the exact same temps with my grey 180. Also had a stuck genuine out of the box. Heck, my temps didn't change at all after replacing the entire cooling system and rebuilding the engine. Always ~203 idle. Very consistent though, I stay within 197-206 at all times. I have seen sub 186 when going down long steep hills or engine braking in 4-low.

I have a britpart 180 I've kept as a spare... I should definitely try it out

 

Jeff, we have almost identical setups in terms of engine. I'd bet your temps would drop too. Most noticable for me has been idle temps and uphill under load. Definitely cooler with the Britpart.

 

Cool. I'm not thrilled to have a 21 degree temp swing though, but I'll give it a try and report back. I have top hats as well and maybe I should just be happy with 198-206