Looks like I have failing coolant thermostat on my 2022 CX-5. Until recently, temperature gauge was steady just under the 210 F point. Now, during this northeast winter, it never quite reaches the unmarked tick (~170F?) and drifts back towards the 120F mark when I slow down or coast. Is this a simple replacement in the radiator in this vehicle?

 

To answer your question, the thermostat is in the front of the engine.


If you are considering DIY but asking where the thermostat is, please don't attempt it.
You are still under warranty, take it to the dealer and get fixed for free.

 

Thanks, Lobstah. That’s the information I needed. Beyond my abilities to fix this, or inclination at my age. I’m not sure that I’m under a warranty that would cover this.

 

I would advise doing some more service evaluations. I am in Northern Ca and what you are describing is very close to my temperatures at this time of the year. Mine may be slightly higher but if I compare the ECU reported which is what you are reading to my analog added gauge there is a temperature diffidence of about 3-7 degrees. Also, if you are using your HVAC system with a higher temperature setting this will affect the reading at the gauge. Before you go to the trouble of changing a thermostat, I would recommend doing some reading with a handheld digital temperature device/gun.

FYI on the highway I rarely during winter months get over 180F on the highway if if I use my heater it can drop to 170F. If I travel up in the Sierra mountains coming home that the elevation is 7000 feet, the long off throttle down the maintain off the throttle for lengthy periods of up to 3-5 minutes can cause the coolant drop to -120F. So what you are posting is not necessarily a concern without more diagnostics to support a bad or problem in your cooling system? I also should mention that when you use defrost your HVAC system automatically engages the AC compressor and the radiator fans which will drop the temperatures in the cooling system.

 

I'm pretty sure they extended the warranty repair for the thermostat repair, so you may be eligible for that. I put a picture below for reference. I know that when we had the issue in Massachusetts as well, and it was during this time in the winter. The only difference was that it wouldn't go farther than a certain temperature which triggered the engine light. I don't recall it fluctuating back down when getting off the throttle like you're describing, but that still sounds like it could be failing.

 

That is a good informational and the point in it is a DTC relating to the issue!

So a scan should be performed of the ECU in the 3 main areas to see if this is a reported negative operating issue to the ECU. If no check engine light this does not necessarily mean that there is not a pending DTC that is being cycled through the ECU.

The warranty is this issue has requirements which state must have reported a problem during the normal warranty period to qualify for the warranty extension.
Now this could be supported depending on the finding in the ECU relating to this warranty extension even if it was not reported prior the warrant period ending if the counters can support the problem was historical. This is rare but still optional. But in this case that warranty extension mentioned also indicates that Mazda notified or attempted to notify owners to qualify for that warranty extension service. because it was not a safety recall there would be no VIN history to report to DMV or other reporting agencies. Also see OWNER NOTIFICATION.

Note: The front of a Skyactiv engine is on the passenger side where all the drive pulleys are. the rear is where the transmission is mounted

 

Couldn't have said it any better myself!

 

I wouldn't take it in until you have the check engine light and code P0126. That code is a requirement of the coverage program.

 

^^^^ Bad advise!!!!!


This is not the best information because the check engine light does not always activate if there is not first ECU confirmed and issue. that is why when some attempt to clear the DYC they are only turning off the check engine light, but the DTC remains in the permeant file area of the ECU until the actual problem causing the check engine light to activate was resolved. Generally, the engine will go through normal engine cycles at which time the ECU will either remove the DTC , clear it completely or leave it in pending for more engine cycles. This can also show up in the I/M monitors that could affect emissions and defiantly cause a failed inspection when emission testing for registration purposes.

Another thing about DTCs as they are a starting point to diagnose but not always the direct cause of an issue. A misunderstood service that many DIY as well untrained mechanic make the mistake assuming when seeing them.
The service advisory states that a DTC must be active on the check engine light but it does also include in the permanent file area and also can be included in the ECU counters but does not have to be the check engine light being active. Even if it was not written it is Mazda's general rule of acceptance for ECU reported problems. Please note that is a 4 page document of which only one page was cut and paste!


Basic 101 Automotive Dignosics ..
Also helps when you are a Mazda authorized warranty service Automotive Diagnostic Technician.

 

Uninformed as usual. I actually own a CX-5, received the letter, and have been through it. You have no idea what you are talking about as usual. That last post was pure buffoonery.