Thanks for your advice Zeeman. Just got back from the Mazda dealer and you were right on the money. They ended up changing my rear engine mount. Only took about 30 minutes to complete. I talked to the service manager and he told me that they changed quite a few of these over the past week or so. He said they got a notice from Mazda head office about this problem a few days ago. Turns out that since the introduction of the 2017 CX-5, Mazda in an attempt to make a quieter Vehicle changed these mounts from rubber to some kind of gel fill. When it goes below -30C this gel gets hard and cracks. He said they replaced mine with a rubber mount so that this won't happen again. I won't know for sure until it gets cold again. Right now its only about -20C and the car was warm from being in the shop. According to the shop invoice the new part is KN3L-39-040. Hope this helps anyone who has engine vibration and lives in a northern climate.

 

Glad that worked out. We are in that extreme cold snap. -34 this morning. -46 with the wind chill. Been running around all day and it purred like a kitten.

 

How is everyone today? It was a balmy -40 Celsius this morning. -50 with the windchill. Poor CX5 is heading out in about an hr. Been plugged in 8:00 AM.

 

Once it warmed up it was so smooth at idle it was hard to tell if it was running. I think that mount was on it's way out for several weeks and finally snapped last Saturday.

 

Just a quick final update. At -24C yesterday morning the car ran smooth at startup and all day long. In my case the rough running engine was definately caused by the gel filled rear engine mount. They told me it didn't really break, just froze solid, and they said it would have been fine once the weather warmed up. With the rubber engine mount in there, I have no issues so far. I highly recommend that anyone owning a 2017 or 2018 CX-5, who lives in a cold climate see their Mazda service manager and discuss this issue.

 

That makes sense as the vibration was intermittent. I think mine did break because of the thumping when starting. That would indicate the engine/transmission was lifting because the starter has a lot of torque. I'm and old fart who used to swap motors and muck around with cars as a teen. I recall that happening once with a broken mount. Of course I'm again just guessing. I didn't know where the dipstick was on the CX5 until last Saturday. Oh how things change over time.

Good luck Voodooman.