Gents, need some help determining problem with van overheating. 2011 Touring L, V6. Replaced thermostat at end of May this year at 150K miles.

Since then it has been randomly using some water/antifreeze, but not overheating. My wife has kept water in it, filling up before any trips.

A couple days ago, it overheated, engine light came on, temp light came on, while wife was driving. She wasn't far from home and drove it home. Radiator was empty. P0117 code. Outside temp was in the 90's and very humid.

I filled it up today with water. Outside Temp is currently 82. I could not detect any leaks. I let it fun a few minutes in the driveway, ran it up and down the driveway and no issue. I checked the oil and it look good, no milky residue. I took it on the road and made it about 2 miles and the a/c shutoff and it the temperature gauge pegged. I turned it around and drove home. I could hear the water boiling in the radiator, the top hose was hot.

As of this writing the van has set for 15 minutes or so and there are no leaks on the ground or visible on the engine. Could this be a water pump or bad head gasket? I saw the ect as a potential issue, is this typically the culprit?

Thanks!

If it's losing coolant, that can only go outside (leak) or inside (crankcase or heater box).
If it's not pumping coolant, I would think the reservoir would become full from the blow-off.
Sometimes ya get real lucky, and it's a radiator cap not sealing & pressurizing, but I'd expect staining.
I'm assuming the cooling fan comes on ? How does the oil look ? Any coolant odor from outside or at the tailpipe ?

And of course the radiator cooling fins are not plugged up from years of accumulated junk. It could be as simple as an air pocket trapped in the cooling system, but if its been hot this many times, now the head gaskets are in question. A compression test/ leak down test is probably in order at this time. If the AC works well, you could be freezing the coolant in the heater core, depending on how much water has been added.

After the head gaskets:

These days, being a new thermostat doesn't mean it is good, they are cheap, replace it again, or test the last one installed. Wash out the cooling fins on the radiator as best you can Junk really collects between the AC condenser and the radiator.. Make sure the cooling fan functions. Then make sure the cooling system is actually full and doesn't have a trapped air pocket. Have the correct coolant freeze level protection.

Check the REAR heating and A/C lines under the van and behind the mid section back.

I'll add:
I always put a new thermostat in water, boil it, and note opening temp with a meat thermometer, before I install it.
If the OP has an air compressor, blow air from behind & through the radiator fins & see how much junk blows out.
Look for traces of coolant (stains, if not wetness) all around anything that carries or contains coolant.

The Dodge FSM I have says .003 minimum open at the temp rating. It's well worth fussing over after I had a stat fail this test years beck.

Oil looks fine, no smells when overheating, replaced radiator cap several months ago with a Mopar cap. Wife says overheating was intermittent- as car would start to overheat, A/C would stop working, then A/C would work again once coolant level was back to normal, and she says this was a continuous cycle while driving for a couple of hours.

I just went thru something similar on my daughter's neon. New radiator, 2 different stats , new cooling fans, new water pump and timing belt , etc etc

No leaks anywhere, Yet it would use about a half-gallon of coolant per day on 50 mile round trip. Took a bore scope and ckd combustion chamber and no issues found.
SO,,,,,

Finally I pulled the head suspecting gasket issue. Tops of the pistons were normal with no signs of burning coolant, no signs of a bad gasket. but. Ckd the head for cracks ( found none ) put a new gasket and head bolts on it. And hasn't been a problem since

Hmmm...that Neon deal is weird...

On some newer stuff, the aux fan comes on with AC. Could be a module or switch or sensor, but the AC cycling on & off with the coolant temp seems to be a clue.

Make sure the fans are working right. If you have 2 fans one should come on with the A/C and the second when the coolant temp is high. If there is only one fan it should come on with the a/c and then go to high when the temp comes up.

With your symptoms and numerous overheating experiences, might want to have or do a block check. it's a test that checks for carbon monoxide in the coolant. If that passes report back.

Fill and bleed the system. Pressure test(make sure it holds pressure). Run the vehicle and check fan operation, observe on/off temps w/scan tool(don't mess with a/c at this point). Drive the vehicle and observe coolant temp w/scan tool. Typically when engines overheat at cruise, it's a coolant flow issue. If they overheat in traffic, it's an airflow issue. You need to figure out exactly what's going on.

Thanks for the info everyone!

Guys, I'm shocked, it was the new parts store thermostat that failed. I put an OEM one on and problem solved.

BTW, the wife has decided after 25+ years in various mini-vans that she now wants an SUV. So if anyone is interested, pm me. I'll give you the details on this one. 152K miles.

Thanks again for all the advice!

thanks for the report and good luck with the sale

Thermostat quality control does seem to have gone down.

Seems to be a “wax” problem today, although I did experience a Dodge OEM thermostat failure where brass arms cracked on a steel body.

In our mandated EV future we can look forward to the failure of a $1 thermocouple ruining a $30,000 battery pack?