[timlemmy88]

Update:

Got the code cleared yesterday and did some testing to make sure the dampers are opening and shutting (they are), then drove back home. The issue is only happening when going uphill at low RPM ranges. When temp begins to climb, if I downshift to raise engine speed it drops back down to a normal operating temp. Assumption is that a bubble trapped in the radiator is being compressed by the increased speed of the pump in that condition.

Did a full drain, flush, refill, and bleed of the coolant system after I got home today. Hoping that the issue was a bubble in the coolant system, but if the problem persists, then I’m assuming my next step is a water pump and/or the thermostat (though I think the thermostat is good).

 

[Johnny B]

The issue is only happening when going uphill at low RPM ranges. When temp begins to climb, if I downshift to raise engine speed it drops back down to a normal operating temp

Well, I must say you are having odd symptoms. You could be right about the water pump. However I disagree, even though water pumps are a weak area they really don't fail like that often. 95% of the time the seal fails, and the impeller and bearing are fine.

I just replaced mine last year, and I read these forums nearly every day. Anyway, in my experience our cars (like most) basically bleed the coolant themselves. Just keep a good level of coolant in the overflow bottle. I know I just triggered someone, I'm ready.

I would replace or at least inspect the thermostat. Also take a good look at your radiator, is it clear. Or does it have ton of bugs or a shop bag up in there blocking the radiator?

Also, FWIW. The water pump is actually very easy to change out. Just a heads up, do not do it without properly torqueing the bolts to spec.

 

[timlemmy88]

Well, I must say you are having odd symptoms. You could be right about the water pump. However I disagree, even though water pumps are a weak area they really don't fail like that often. 95% of the time the seal fails, and the impeller and bearing are fine.

I just replaced mine last year, and I read these forums nearly every day. Anyway, in my experience our cars (like most) basically bleed the coolant themselves. Just keep a good level of coolant in the overflow bottle. I know I just triggered someone, I'm ready.

I would replace or at least inspect the thermostat. Also take a good look at your radiator, is it clear. Or does it have ton of bugs or a shop bag up in there blocking the radiator?

Also, FWIW. The water pump is actually very easy to change out. Just a heads up, do not do it without properly torqueing the bolts to spec.

Thanks for that info.

The radiator is clear, one of the first things I checked, which is why I was concerned about the shutters blocking airflow.

When watching temperatures on my way to work today, they seemed to fluctuate between 215 and 237. That high end seems like it shouldn’t get quite that hot with the thermostat full open, but I didn’t see a repeat of my issues from my long weekend.

You’re probably right about triggering someone on that bleeding discussion. I did go ahead and use the bleeder screw in the top corner of the radiator, and had the car on jack stands to make sure that was the high point. Someone stripped out the screwdriver slots, and rounded the corners aren’t on it, so I had to use a 1/2” socket instead of 13mm. I’ll find a replacement when I order whatever parts come up next for this car.

 

[timlemmy88]

Update:

After another weekend spent traveling for baseball and mother's day, I can maintain 70 without the heater on, so long as I don't go into 5th gear. Temps fluctuate from 212-237F in 5th, and from 217-245F in 6th. I downshifted and temps dropped almost immediately back down to around 235F, then when I topped the hill they dropped down to around 225F and then resumed the cycle discussed above. If the thermostat is supposed to be fully open at 228F, should I ever actually reach these upper temps? I wouldn't think anything above 230F would be reached under normal conditions, but I'm new to an (automotive) operating system that goes that high.

What is special about 6th gear in a Cruze Eco? I know the shift knob has a green dot that the 6 sits in, but does it actually do anything to the car? Because the problem is only in 6th gear. I'm still getting 38mpgs (272 miles on 7.2 gallons) in 5th gear, but I can't just live with a workaround and not fix a problem.

Is there something that isn't related to the cooling system that could cause this? Any other symptoms to look for? My brother mentioned a small head gasket leak, but I would think that should happen in all gears, not just 6th. Also, one of the replies to my Facebook post was that the A/C not working could be a sign of a head gasket failure. Is that actually a thing that happens on these cars? The A/C works, but isn't very cold. After hooking up my brother's diagnostic tools he said the pressure was low while he tracked live data from the ECM, so I assume that's the reason there. Is it possible that my fan isn't working properly? I know it comes on, but how do I test all three speeds to make sure it's doing what it should? Is there a way to test the shutters/force them open?

Sorry for rambling, just trying to get my ideas out there so I have something to work with.

 

[timlemmy88]

(Hopefully final) Update:

After my trip last weekend I was planning to stay home this weekend and tinker, but am traveling for a funeral.

I added a bottle if Water Wetter to the coolant Sunday so it could circulate during my commute through the week. During my 100 mile trip today I spent the entire time in 6th on cruise control at 75mph and hovered around 210-215*F.

So for those of you fighting an issue like this, give it a shot.

 

[Drgold]

copied from my Facebook post with edits for the engine code. All this happened on Friday.

My new to me commuter with 208k on the clock. 2012 Cruze Eco with the 6 speed manual.

Going through some overheating issues, and am thinking my active dampers are failing. Started today on the interstate. Not losing coolant, temperature tracks up and down like it should, until it just gets too hot for the thermostat opening to do anything.

Overheating hasn’t been an issue during my 25 mile commute for the last month, but I only spend about 5 miles on a major highway during it. When I dropped speed to less than 60 on the interstate today and turned my heater on I didn’t have the problem anymore.

Is there something that could cause this besides these shutters/dampers that I’m missing?

There is a CEL on as of today with code P00B7 for low coolant flow

You
Just for explanation. My chevy cruze 2012 1.8 kept bubbling and spitting out the reservoir and I changed cap changed the pump thermostat tried blue devil...nothing worked. The actual engine wasn't overheating. After all that I changed the whole reservoir tank and it stopped so I think it was letting air in through the exit valve on the reservoir tank. 4 or 5 mechanics didn't figure this out before it was finally done and repaired with a cheap tank. Thought people might want to know since there is no video on that.