Noticed my Mazda 3 2020 has been running cold lately. Is this an issue? Outside temps will be 40° F - 50° F.
Picture shown was taken on highway after driving for 1.3 hours.
This is sort of a known issue for all non-turbo 2019-2022 model years for Mazda3 (talking here about US market).
Mazda doesn’t use a mechanical thermostat but an electronic one called Coolant Control Valve (CCV) and in the issued TSB (that got several revisions) they mentioned the problem is within the CCV with the fail-safe thermostat which seems to be opening too soon (some folks opened the CCV and manually adjusted that fail-safe thermostat and seems that the problem got fixed for them).
Personally I had this CCV replaced twice under warranty and issue wasn’t fixed and ended up being unsure on the root cause with dealers ended up being out of ideas and with open case with Mazda.
What is known now is that turbo engines never used CCV and from MY2023 they moved back to a classic thermostat and seems to have abandoned the CCV idea completely.
- 2019-2022 model has the part (15-16Z)
- 2023 model has 15-17Z which is listed as “Outlet, Water” and there is also a part called “Cover, Thermostat”
Your thermostat has failed. They fail open, which is why you car is running colder than it should
Just a thought, why having your engine run colder isn’t better? Usually the less heat the better longevity.
Better than overhearing I’d assume ha
Thermostat failed. Very easy fix
This happened to me and I live in a cold place so basically it meant I was getting no hot air in the cabin. The dealer replaced everything for free and said mazda is aware of the problem. I had the same vehicle as you by the way. Also make sure you check your coolant level after the repairs are done. It may be significantly lower than normal.
Do they even use thermostats anymore? It’s probably some overly complicated electronically controlled valve that will be super expensive to replace because a simple wax-filled cylinder that has worked fine for the last 100 years isn’t precise enough to accommodate today’s emissions regulations.
Your going to need a OBD code reader diagnostic tool , it’s a device that you hook up to vehicles OBD port. It communicates with the vehicles computer. Go to AutoZone, they will scan the code for free.
That’s not cold Doc. One look was all I needed. That’s normal operating temperature.
My girlfriend’s cx5 had the same issue, the dealer replaced the thermostat for free under warranty. There is a tsb out for it.
Same with mine as well — CX30.
Coolant control valve If you have powertrain warranty, it’s covered
Thermostat could be stuck in the open position. P0126 fault code. There is TSB for this.
Mine just started to leak around the spark plug at 22k.
This is almost always a stuck thermostat or similar. These systems are designed to “fail open”, so that you get too much cooling (mostly harmless) instead of no cooling (engine go bye-bye).
Mazda really eating these warranties aren’t they
Sounds like a thermstate issue