I have been having some cooling issues with my 5.2 Dakota, sometimes it seems to cool normally, others it over cools, or continues to heat up until it is about 3/4 of the way up the gauge and won't come back down.

I suspected there either was not a thermostat in it, or that the waterpump was on its' way out. However once I started pulling the thermostat it looked like the housing had never been touched.

I pulled the thermostat to find this:




I've seen some rusty, mangled, and tore up thermostats but never one that broke a leg off. I put in a new 180* thermostat in and burped the system. So far it runs much cooler, about 1/3 or a little less up the gauge, AC blasting, sitting in traffic.

 

That's different alright. Looks like the leg had a weak spot where it was crimped..

Do you know what the brand is? I'd like to avoid it, lol.

 

It looks like the stock one honestly. I tried to read the number and temp on it, but everything was so worn away I couldn't make out the letters. I put a Stant 180* in and drilled a small bleed hole in it, burped it easy and it's been great since then. It also looks much thicker than the broken one I pulled out.

 

I have been working in the aftermarket parts industry for 10 years & I have never seen a thermostat do that before. Thanks for sharing!

 

I had one like that at work last fall in a International diesel in a 7400, "3 ton" plow/dump truck.
also I would definitely have stayed with a stock 195* thermostat/ dont matter what temp the busted one was rated at, it wouldn't have worked right regardless.

 

I generally stick with a stock temp range thermostat, but I can't see the difference in mileage being much at all over the 180*. I even go one step hotter in some of my diesels, but on a gasser that sees 110* days in traffic, with 200k miles on it, and some towing duty, I opted for a bit of wiggle room to avoid detonation or overheating in traffic.

This truck also has the Max cooling option but still seems to stay undiscernibly close to stock temp on the gauge even with the 180* stat.

Why stick with a 195*? I do have a spare one, but I'm not seeing codes, or issues being stuck in open loop longer than usual.

 

I find my 94 runs better in the cold and it does better in the summer with the 180 thermostat. Mileage goes to crap when i run the ac but at least it doesn't overheat.
On another note does that sound like myu compressor is going out or is it normal to lose > a couple miles a gallon when running the AC?

 

Well, consider how many horsepower that A/C compressor is pulling.

Mine pulls enough that with 360,000 miles on the clock, the vacuum drops and I can't use the cruise control to hold at 75MPH on I-49 in Louisiana ...

RwP

 

That makes sense Ralph.