2013 Dodge Journey 2.4L - Unable to reach Normal Operating Temperature

[ronnellbagz]

Hey guys! I recently noticed that my Temperature gauge reads low. The needle wont reach the center anymore regardless of how many hours of driving. As a result, I don't get enough heat in the cabin anymore which is kind of inconvenient especially in winter season (-20C, Canada). So I hooked my OBD scanner and noticed that my Engine Coolant Temperature rest in between 67C ~ 72C. I use excel to plot the chart.  I checked my vents actual temperature using a thermocouple and I get an average reading of 60C which I think is normal with respect to my current Engine Coolant Temp due to heat loss and cold weather outside. (Settings: max heat, max speed & focus air flow to front vent only).

 

OBD2 Scanner:

• Engine Coolant Temperature = 67C~72C
• Ambient Air Temp = -14C ~ -20C

 

Dashboard Temperature = 69C

Actual Thermocouple Readings (Vent) = 60C 

 

 

 

Now, I have been searching several forums & Youtube videos about it's possible causes and majority says it could be the "thermostat" and "temperature sensor". However, Repair Manual specifically says not to change thermostat for the lack of heater performance or temp gauge position unless a DTC is present.... I don't see any DTC in my scanner! 

 

2 years ago, I replaced the whole Thermostat Assembly because there was a leak but it was running fine after that until now. I bought the GATES CO34760 (Standard Replacement) Includes Thermostat; Includes Seal, Integrated Thermostat; 77C (172F) Degree / 95C (203F) Degree; OE Temperature.

 

 

I do understand that this Journey has 2 thermostat but I am puzzled when does the 77C thermostat opens? and when does the 95C thermostat open?

Anyone here experience the same issue before? Fix?

 

Please let me know.

 

Edited February 24, 2022 by ronnellbagz

[2late4u]

do what does the info system  tell you what the engine coolant temperature is? should be around 195 -203 after fully warmed up, probally the state is sticking open   i am surprised you dont have a engine light due to you saying it is around 70 according to your scanner,,,as i mentioned i would install a new thermostat

Edited February 24, 2022 by 2late4u

[ronnellbagz]

My info system(dashboard) is showing 69C. Almost the same as what I have read in OBD2 scan.

 

@2late4u, there are 2 thermostat in there.. do you know which one i should replace? 
 

77C thermostat or 95C thermostat?

[2late4u]

3 minutes ago, ronnellbagz said:

My info system(dashboard) is showing 69C. Almost the same as what I have read in OBD2 scan.

 

@2late4u, there are 2 thermostat in there.. do you know which one i should replace? 
 

77C thermostat or 95C thermostat?

just replace them BOTH, 

[John/Horace]

I agree with 2late4,  change both if you have coolant manifold removed. Replace all seals if reusing the existing assembly, orings and molded flat seals. People often have leaks if they try to reuse compressed seals. Sometimes it is cheaper to buy the whole assembly which comes with most seals;   the existing cabin temp sensor probe is then moved to new assembly, it also has its own oring.

 

The 77C and 95C thermostats are designed to open at their rated temp, but with cycling of spring you can see a bit of variation around that number.  I think the lower temp setting thermostat gets you faster heat into cabin on cold start ups,  and the 95C is your engine coolant thermostat. If your cabin hvac air filter in dash is over 3 years, change that as well, it affects air flow into cabin. Gets forgotten. 
 

You may not be getting a code with your off the shelf cheaper obd scanner. They are mainly for engine codes. You need a very expensive higher end scanner like dealer ship or good repair shops have.

Edited February 24, 2022 by John/Horace

[John/Horace]

 

[ronnellbagz]

@John/Horace & @2late4u, Thanks for your reply. I will try to replace both Thermostat. However, looking at different brands & different website such as RockAuto or Napa, there seem to be conflicting information.

Can you guys confirm if my interpretation is correct?

• Primary = 203C
• Secondary = 77C

Thanks!

 

[John/Horace]

Yes it is correct. If you read my post, I used the Gates from Rockauto and it fit fine but had a small drip, even after a retorque of the plastic housing.  Moved both new thermostats to the old original housing and reinstalled it, no leaks in over two years now.

Order the oring for cabin temp sensor mounted on the coolant manifold,  new kit never had the small oring with it. 

 

The original thermostats were actually still ok, but one of gaskets was dripping over night. I bought Gates because they make lots of factory parts and I’ve never really had an issue with their timing belt kits, water pumps etc. Mopar Canada on line has about 25% off list price and will ship. Oem stuff is usually better stuff, guaranteed fit as well. But both thermostats, seals and a new housing  I believe would be around $600 plus in Canada. 

 

https://www.rockauto.com/en/catalog/dodge,2013,journey,2.4l+l4,1505072,cooling+system,thermostat+housing+/+water+outlet,10337

 

 

Edited February 25, 2022 by John/Horace

[Armando G]

Mine was doing the same a couple of weeks ago along with the CEL coming on telling me to change the thermostat. Mechanic told me to clear the code and drive it a little longer. He told me it could have just gotten stuck. No code or issue since then - lucky I suppose. 

[John/Horace]

If it sticks then the mechanism is starting to wear out I think. Will need to be changed soon.

 

On Ronnykbags car it seems like the main 95C thermostat is allowing some flow all the time; so engine doesn’t get to full temp.

Then the second cabin thermostat can’t reach its designed max temp. He could leave main housing in place and just remove and replace the engine cooling thermostat. Cabin one is probably ok for now. But thermostats are a wear item. Leaks on this coolant manifold seem to be common. Dealing with it all at once probably better option.

[ronnellbagz]

Thank you all for your inputs. I can concur that this it is indeed an open thermostat issue.

 

As a DIY mechanic (and for my own satisfaction), I really wanted to pinpoint which thermostat was really bad and not just replace the whole assembly(easier option) , for the reason I go thru this trouble.

Anyway, this morning I got the chance to diagnose the issue further. 

1. I had the Engine Cooling system bled, just to be sure there was no air in the system. Got some tiny bubbles out by squeezing the radiator hose but not really a lot.
2. Run the engine at idle for more than 30mins.  
3. MAX heater but Fan OFF. By turning OFF the cabin fan, I was able to reach coolant temperature @77C for the first time. Both OBD and Dashboard temperature reading showing the same readings and my temp gauge dial was almost in the center. This proves that my temperature sensor & dial gauge was actually working. However, if I turn ON the cabin fan, the temperature will drop significantly to 59~63 depending on fan blower settings. This make sense because the blower will somehow dissipate the heat of the heater core into the cabin.
4. I kept the engine running and rev to 2500 rpm for 30 seconds several times and now I was able to reach 103C (yey!). At this point, my temperature drops and my radiator fan turns ON momentarily. Although, I missed to observe the part wherein my 2nd thermostat (95C) exactly open but I did see some coolant fluid action, the coolant level dropped (which means T'stat No.2 [95C] opened, and coolant rushed in). Btw, I am using a radiator funnel. This proves my other T'stat is still OK.

My previous comment (drawing) was actually wrong. This should be the correct one. Might be useful for those who encounter the same issue.

 

Primary Thermostat = 77C (In Line, Inside Thermostat Assembly) <------- ROOT CAUSE (Stuck OPEN)

Secondary Thermostat = 95C (Attached to Engine Block)