2011 Dodge Journey Mainstreet with 3.6L V6 overheating

I apologize in advance because this is gonna be a long one. We have an auto techs worst nightmare sitting in the shop right now. The vehicle that keeps presenting new problems for the same original complaint and refuses to give up a definitive diagnosis.
This Dodge was first brought in with a complaint of overheating. Unfortunately we were unable to do an initial test drive because the wheels installed on the car were not the proper wheels. They had some kind of hack job inserts installed in them that had to have been some sort of half-baked shade tree job. They weren't even the correct bolt pattern. We deemed the vehicle to be unsafe to drive, so we had to make do with what tests we could perform on the lift.
So, the overheating. First order of business was the basics. The coolant had been boiling in the reservoir when it first pulled in (witnessed by our service advisor) and we could see that there was a new water pump installed. So my first concern was air in the system. Second concern was a leak. Pressure test is in order. Pull out my pressure test kit and pump it up to 15 psi. All good. No pressure loss at all. Pressure test needs to be done at temperature as well, so I bled off the pressure and left the tester installed. I'll monitor that when I run the engine. Third. Is the new water pump working. Run the engine, get it a bit warm and we have heat at the dash. Coolant is circulating. In addition, my pressure tester at this point is showing a steady rise in pressure with no shaking needle. At this point I also opened the bleed screw on top of the thermostat housing. I got a little bit of air, but nothing significant. So far, so good. Fourth. Is the thermostat opening. Monitor temp of upper rad hose with an IR gun and by touch while watching temp PID on scan tool. Hose gets hot at the right temperature. Cross that one off the list. Next. Is the fan working. Go to the scan tool and command the fan to turn on. Works on high, not on low. Check out the circuit and turns out the low speed fan resistor is defective. Replaced the resistor and now the fan works perfectly. Easy enough. We get proper wheels and tires on the car, and now we can test drive. Vehicle overheats again, but what's odd is it only overheats after driving at highway speeds for 5-10 minutes, at which point you also lose heat at the dash. In addition, when I pull over and idle, the temp gauge comes right back down to the normal operating range. So I limp it back the shop.
So since it only seems to overheat under highway loads and does fine at idle, my thoughts at this point are a radiator with fouled passages. So the bumper fascia comes off, pull out my thermal camera, and fire it up. Bingo!! Lower third of the radiator is showing cold in the thermal view. Ok, we have a definitive answer right? Wrong!! After replacing the radiator, filling and bleeding the cooling system, and another test drive, we still have the same problem.
So at this point, the only thing left is the water pump. (I know. Head gasket right? I'll get to that.) We didn't install the water pump. This is the first time this vehicle has visited our shop. So we have no idea if the pump was any kind of quality, if it was new, used, refurbished. Who knows. And the loss of heat at the dash when the overheat symptom presents itself is a significant concern. So we decide to pull the water pump to verify its condition and that it's the correct part, i.e. not a reverse flow pump. I don't think a reverse flow water pump is even available for this engine, but I've seen weirder. So off comes the water pump. Waste of time. Pump is in good condition and is the correct part.
So at this point the only thing left is a blown head gasket. We had initially dismissed this as a possibility because of the lack of a definitive symptom pointing in that direction. We don't overheat at idle. It doesn't consume coolant. It only expels it after driving under a highway load. But we do a chemical hydrocarbon test anyway. Result is negative. Chemical doesn't change from its original blue color.
And that's the point we're at right now. Anybody have any ideas where to go from here?

Nightmare, no night terror job, sudden loss of heat at the dash means loss of circulation in the bypass/heater pipes so either coolant loss or boiling but you seem to have covered all the bases and more. So what is left ? We can probably discount an airflow issue because the problem only occurs at highway speed, and on modern engines it isn't going to be spark timing or lean mixture issue, so that brings us back to coolant circulation or some kind of head gasket or cylinder liner issue although you have already tested for these. ...

Has the water pump got a plastic impeller ?

With thermostat open, rev up engine and check for collapsing radiator hose between radiator and pump.

Agree with Andy, some sort of restriction. I looked up coolant routing and made this:

I wouldn't dismiss the head gasket. With the color changing combustion leak test fluid you can, pretty much, count on a positive result. But, a negative result does not, necessarily, mean no problems.

This case reminds me of an Equinox with a 3.4 L. It came in with an overheating complaint. I could find no faults with the cooling system. It passed the color changing Combustion Leak test multiple times. It would take a 30-40 minute test drive, on the highway, before it would lose heat from the vent and, finally, overheat. To make a LONG story short, a head gasket fixed this Equinox. Since then, I have had a couple others that I was confident the problem was a head gasket, but the Combustion Leak test did not detect it until I became "aggressive" with my Combustion Leak testing. Now, I don't give up on it so quick. Do the test for 20 minutes, or more. Keep the RPM's up, and power brake frequently.

To answer the impeller question, yes, it is plastic. Saw no signs of it spinning independent of the shaft when I had the pump off. Just to be sure I secured the pulley hub in a vise and grabbed the impeller with a pair of Knipex and tried to turn it. It wouldn't budge. So I'm confident the water pump is turning consistently.
We also just finished re-running the hydrocarbon test and are still coming up with a negative result. Will probably take Chads advice and do it yet again but get after it a lot harder.
Jreardon, to address your point, both hoses are clearly visible and they are not collapsing, at least not that we have observed. So we're fairly confident we have a good flow through the system.
To address the thermostat, I should have mentioned that I replaced it when I replaced the radiator. It was only a couple extra minutes so we figured why not? However, after running the hydrocarbon test this morning and consulting with our service advisor, (who is a master tech himself) and our other lead tech, we have decided to remove the thermostat and run the vehicle without it to help further eliminate any possibility of an airlock. I've been vacuum filling the system every time, but at this point we're trying to come up with every thing we can to be certain that there is no possibility of air in the system.
The saga continues!! Will post updates as I have them.

My guess is a lack of coolant flow. I think this would explain the radiator not being hot across the bottom. The bottom radiator hose collapsing sounds like a good possibility. Some used to have a spring inside to prevent collapse. Could the water pump be slipping pulley to shaft or belt to pulley?

The diagram provided by jreardon is interesting. If the coolant flow through the oil cooler was excessive, would it not rob the engine/radiator of it's share of coolant flow?

Any updates on this? I am having the exact same thing happening with my 11 dodge journey. Taking it into the shop tomorrow. I thought I was reading what was happening to my car, less the rim issues.

I'm with Chad in not being ready to discount a head gasket type fault.
Like mentioned previously, positive is positive, but negative is just inconclusive. Most recently a Caravan comes to mind that passed the chemical test multiple times for another tech until I suggested doing it with the engine screaming hot.
I also employ a more aggressive test method with the chemical tester like Chad does now.
I have also seen head gasket type failures where the car would not over head until driven. A Suzuki from last summer would idle for days like a dream, but once driven would over heat rapidly.

Was a resolution found for this? Fighting the same exact thing

I would use a scope to do a relative compression test, use a pressure transducer on the radiator and use a third channel as a reference (only to see which cylinder). If you have a bad head gasket you’ll see it for sure. Waaay more accurate than a chemical tests.

Hello i would like to know now it ended your story we have exactly the same problem

Hello did you find the problem with your Journey we have the same problem

Initially, when you said the coolant was observed to be over heating in the reservoir, I wondered if that was actually just combustion gas, so I'd be interested in the results of another head gasket check too. Maybe a leak down test if you don't have the transducer setup?

Just thinking of what else would reduce the boiling point, if it is boiling - bad radiator cap would, without being able to pressurize the system, and the cap usually comes off for a pressure test at the radiator.



Nissan Tech

The plastic reservoir has a hairline crack in it. $250 part.