2018 CX5 with 9,000 KL
 

Hi I'm new to the forum. We live in a cold climate. -30 Celsius. We always let it run for about 5 minutes when it gets that cold. Today I started it with the remote and after opening the door I had to restart it which is an anti theft feature. It had a thumping noise turning over which went away after it started. Idle is rough when cold which I believe is related to the catalytic converter. It seemed to run fine despite the rough idle and we take it easy unit the blue temp light turns off. I'm taking it in on Monday but thought I'd ask here.

Thanks in advance.

Hello Zeeman, I also live in a cold climate and last weekend when it was -27C here exactly the same things happened to my new 2018 CX-5 with only 1,000 km on the odometer. Started slower than normally and rattled around while cranking then was very noisy at about 2000 RPM for about 5 minutes while warming up. I finally shifted into gear around 1500 rpm and then the rpm dropped to about 800 and the car shook and vibrated like an old tractor. Even after warm up the car still ran rough at idle. Not a total missfire, but more like a couple of cylinder didn't have complete combustion. One other thing I noticed is that the oil dipstick level was higher than normal and I had water and oil mixture in the filler cap (looks like peanut butter).
Took it to the dealer after the weekend and they told me it was due to many short trips and the engine not fully warming up. Their fix was to do an oil change. When I picked up the car it was warm from being inside their garage and ran like new.
Now almost a week later the same thing started happening again. Just a slight missfire at first, but now running extremely rough at idle while warming up. Can't be the water in oil thing because it has new engine oil and I have been taking the long way home to make sure the temp guage needle is centered. This morning it was -31 here and I have not gone out to try it yet, but I'm sure it will be running rough in this weather, so I will be heading back to the dealer again this week. Just seem like the car does not like cold weather.
I'll keep you informed with any new developments, and please do the same. I like the car, but this is my 4th Mazda in a row and this is the first time this has happened.

Sorry I forgot to mention that my CX-5 is the GT with AWD and 2.5 L engine, in case that matters to the above comment.

Subbing to see how this turns out. I also live in a cold climate. No issues so far - but interested to see if there is an explanation.
My 2018 survived the latest cold, parked outside in northern MN. If this was typical all season long temperatures a block heater would be an appropriate investment. After 40 hours with low of -30C and high of -15C it started (reluctantly) and ran fine. Further south where I live we only see these temperatures 10 - 14 days over any winter season. And, at home the car is in a garage overnight.

Turned out to be a broken transmission mount. It appears the factory mounts are not suited for these types of cold conditions. There was another fellow in at 7:00 AM with 6,000K and the same issue. We were both out within an hour. It is not on a recall notice at this point but they are changing them out. Not surprising. I worked in manufacturing for 35 years and suppliers are always trying to save money. Whatever the rubber or other compound mix they use probably freezes and snaps. I'm just guessing about this but that would seem to make sense.

We didn't buy the Honda CRV due the oil dilution issues - apparently. That was that based on what I read anyway. Seems their new turbos are suffering this issue from short runs. I checked the oil yesterday and it looked fine. It was changed in early October and only 2,000K on it. We have been doing a lot of short trips as well lately and no issues. I'll keep an eye out for that. Hope you get that resolved Voodooman. Ours is the GS, AWD and 2.5 L.

Forgot to say. The exhaust is configured in such a way that the catalytic converter is further back than usual. I read the engine changes timing to warm up the converter faster which can result in a little noise for about 30 seconds when cold. Some said it was like marbles in the exhaust pipe. This apparently is not a problem, just normal operation. This is supposed to improve gas mileage. It seems slightly noisier to me but I don't find it annoying. Maybe older models are noisier. At least now I know what this is.

Thanks for letting me know Zeeman. Took the car for a ride tonight on the highway and same thing. At highway speed not very noticeable. Most noticeable during warm up and each time the vehicle shifts into a higher gear. Seems worse between 1000 and 1500 RPM. I have an appointment tomorrow at 9:00 with the dealer. I will get them to check the transmission mount. I will post back tomorrow after my appointment.

I did a stretch on the highway going to the dealer. Bad vibration at 1500 RPM.

By the way. There were several conversations going on. I heard transmission mount. Just to be sure get them to check the motor mount as well. They knew what was wrong before either CX5 went on the hoist.

Good luck.

A very good article. Was more an issue with Mazda diesels.

https://autoexpert.com.au/posts/engi...facts-for-2018

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.