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JDJEEP123

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Discussion starter · #1 ·
This applies to a '07 Jeep Compass 4WD 2.4L, but it sort of a generic question.
I recently replaced my water pump (I was working on another project and decided while I was at it and it was convenient...) and my Jeep still gets a tick to the right of halfway. Today It creeped up about 3-4 ticks, which in my opinion is too hot. I know it has 2 stats in it (primary and secondary) and I know how they operate or are supposed to operate, I should say. My question is: How do you definitively know which stat is bad (when only 1 fails, theoretically speaking). I don't need the whole spill of your supposed to change both when you change 1 and your supposed to change the stat(s) when you change the pump and coolant. I normally do, but here lately I've spent a fortune on my 2 cars, as I've had a stroke of bad luck we'll call it lol. Any help would be greatly appreciated.
Thanks,
JDJeep123
 
#3 ·
I would suggest trying to get an actual temperature versus just how many ticks above halfway. Gauges can vary a little. Find someone with a scangauge (or similar) or an IR thermometer that can check the temperature. Even just taping a stick-in style meat thermometer to the upper radiator hose would give you a fairly close reading once you hit full hot and the heat saturates the hoses. You'd probably be within 5 degrees or so.
 
Discussion starter · #4 ·
I have an E-Gun that I've used on it and its 216F +/- 1 degree. Also, I first noticed it because it has never run past halfway. Even sitting in 100F weather idling at a red light for several minutes. These aren't "fail safe" tstats are they (i.e. fail open instead of closed)?
 
#5 · (Edited)
JDJEEP123 said:
I have an E-Gun that I've used on it and its 216F +/- 1 degree. Also, I first noticed it because it has never run past halfway. Even sitting in 100F weather idling at a red light for several minutes. These aren't "fail safe" tstats are they (i.e. fail open instead of closed)?
Click to expand...
They can get stuck either way.

However-
(per 2007 MK service manual:)

07 - Cooling / Engine / THERMOSTAT/Diagnosis and Testing
DIAGNOSIS AND TESTING - ENGINE COOLANT THERMOSTAT
The thermostat is operated by a wax filled chamber (pellet) which is sealed. When heated coolant reaches a predetermined temperature the wax pellet expands enough to overcome the closing spring and water pump pressure, which forces the valve to open. Coolant leakage into the pellet will cause a thermostat to fail open. Do not attempt to free up a thermostat with a screwdriver.

Thermostat diagnostics is included in Totally Integrated Power Module's (TIPM) programming for on-board diagnosis. The malfunction indicator light (MIL) will illuminate and a diagnostic trouble code (DTC) will be set when an “open too soon” condition occurs. Do not change a thermostat for lack of heater performance or temperature gauge position, unless a DTC is present. For other probable causes, (Refer to 07 - Cooling - Diagnosis and Testing) . Thermostat failing shut is the normal long term mode of failure, and normally, only on high mileage vehicles. The temperature gauge will indicate this.
 
#6 · (Edited)
Also from the '07 MK service manual:


07 - Cooling/Operation
GAS ENGINE
The primary purpose of a cooling system is to maintain engine temperature in a range that will provide satisfactory engine performance and emission levels under all expected driving conditions. It also provides hot water (coolant) for heater performance and cooling for automatic transmission oil. It does this by transferring heat from engine metal to coolant, moving this heated coolant to the radiator, and then transferring this heat to the ambient air.

When the engine is cold and both the primary and secondary thermostats are closed. The coolant will circulate through the engine, heater system, and the bypass. The cooling system has no flow through the radiator
As the engine warms up, the primary thermostat will start to open at 77 °C (170 °F). Coolant will start to flow through the radiator and the internal transmission cooler. The primary thermostat will fully open at 95 °C (203 °F).
The secondary thermostat will start to open at 95 °C (203 °F). This will increase the coolant flow through the cylinder block and cylinder head and the radiator. The secondary thermostat will fully open at 104 °C (220 °F).

07 - Cooling/Diagnosis and Testing
FLOW CHECK
WARNING: Do not remove the cooling system pressure cap with the system hot and under pressure because serious burns from coolant can occur.

To determine whether coolant is flowing through the cooling system, use one of the following procedures:

If engine is cold, idle engine until normal operating temperature is reached. Then feel the upper radiator hose. If it is hot, coolant is circulating.
Remove pressure cap when engine is cold, remove small amount of coolant. Idle engine until thermostat opens, you should observe coolant flow while looking down the filler neck. Once flow is detected install the pressure cap.
 
#7 ·
JDJEEP123 said:
This applies to a '07 Jeep Compass 4WD 2.4L, but it sort of a generic question.
I recently replaced my water pump (I was working on another project and decided while I was at it and it was convenient...) and my Jeep still gets a tick to the right of halfway. Today It creeped up about 3-4 ticks, which in my opinion is too hot. I know it has 2 stats in it (primary and secondary) and I know how they operate or are supposed to operate, I should say. My question is: How do you definitively know which stat is bad (when only 1 fails, theoretically speaking). I don't need the whole spill of your supposed to change both when you change 1 and your supposed to change the stat(s) when you change the pump and coolant. I normally do, but here lately I've spent a fortune on my 2 cars, as I've had a stroke of bad luck we'll call it lol. Any help would be greatly appreciated.
Thanks,
JDJeep123
Click to expand...
my grandson's mother has a 2011 Patriot which hasn't had het this fall. where are both states & how do I change them? I purchased the one advanced auto parts said is needed but didn't know there is a 2nd thermostat??? I'm confused?? PLEASE HELP -- I ESPECIALLY DON'T WANT MY GRANDSON WITHOUT HEAT!!!!!!
 
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