Thermostat OEM Volkswagen or OEM Mazda

I had a bad thermostat and it's only indication was the temp rising when going up hills under sustained load.

I had this year ago, thermostat was stuck closed, so coolant couldnt go to big circle and into cooler, it went up after 10 minutes of highway driving up to 115° (obd temps) on dash it wasnt that much

I used the genuine part as there is no desire to redo it again too soon.

It has been two weeks since the repair without issues, so I am going to call this one solved. If I was paying for this out of pocket in the future, I would only replace the thermostat and not the pump as that is what was closing and causing the issue.

I had the same issue on my 09 Mazda 2.3L. Everything looked good on the dash, but the thermostat let too much coolant through, over cooling the engine. My CEL came on, I reset it, and it reappeared. Long drives on the freeway in cool weather was the scenario that triggered it, as the radiator is very effective at speed, and the engine isn't working hard cruising on level ground at freeway speeds. I bought the thermostat "cover" (it's the plastic assembly with the thermostat integrated in it-- PN LF70-15-170) for $57 from Amazon and installed it last November and the CEL has not reappeared.

My 2021 Mazda3 Turbo has classic thermostat failure symptoms: \n\n- Erratic warm-up (sometimes stuck cold, sometimes near overheating). \n- Upper radiator hose stays lukewarm even after 20+ mins of driving (revved to 3K RPM to test). \n- Housing burns hot, but hose never gets scalding\u2014clear sign of a stuck thermostat.

They kept it for another day and were obviously able to replicate the fault and replaced the Thermostat as they thought it was sticking causing the Temps to fluctuate.

That's due to their faulty thermostat for which they don't want to assume responsibility and call it what it is - a recall.

Original was stuck open, replaced with new VW which now appears to be stuck closed. ????. Fortunately I have recently acquired a new OE thermostat on clearance for jollies.

Our 2022 CX-5 Premium Plus (non turbo) is going in for its 3rd thermostat replacement next week. Each time it’s been replaced at Mazda under warranty with an OEM part. Vehicle will hit 90,000 Miles this month. Does this thermostat wear seem excessive or is it normal for these? Bought brand new and it’s been the only problem, other then general maintenance