Mercedes CLA Forum banner

1 - 11 of 11 Posts

Registered
Joined
521 Posts
Discussion Starter #1 (Edited)
I was driving from PGH -> Philly (Ive done this trip at least 15 times in the past 2 years). Its roughly 300miles
I thought it was a transmission issue at the time, so when I found out from the dealer it was a misfire - I was surprised.

Regardless, here is the origin story for my issue for those interested.
30miles out of Philly, my car shifted (auto- S mode) from gear 5 to 6. Immediately it started to rumble/jitter/shake + engine light turned on. I began to start loosing power. So I pulled over and the turned off the car. Restarted - issue fixed and engine light disappeared.

10 miles out of Philly, the issue came back. This time again from gear 5 to 6. So shifted in manual mode and slowed down till I was in 5th gear. Was fine for a while until issue (shaking/jittering/rumbling/power loss) started in 5th. Slowed to gear 4, and the issue resolved. The issue started happening at 4th gear. Thankfully I got to my apartment and parked. Car got towed to the closest MB dealer.

So it seems they did a software fix/update - has anyone experienced this before? My only concern is that the issue may happen again as it was some kind of "software problem"

This is what the dealer wrote:
Pg1
scan1gki1.jpeg
Pg 2
scan2vbk2s.jpeg
 

Registered
Joined
178 Posts
45 or 250?
 

Registered
Joined
4 Posts
Cylinder Misfire

I had the exact same issue with my 2014 CLA 250. Started at 69000 km, had cylinders 3 & 4 misfire. Loss of power and strong vibration and CE light on. Then after shut down and restart, it would run fine and CE light would clear. First fix from dealership was to replace fuel rail sensor (covered under star cert. warranty). Car ran well for a couple weeks, then the misfire re-occurred. I took it back to the dealership, they ran compression test and found low compression and "scorching" in cylinders 3 and 4. They ended up having to send the engine block and cylinder heads to Toronto for repairs (apparently the only Mercedes certified machine shop in Canada). Total repair time took approx. 7 weeks. Fortunately repair and rental costs were covered under warranty. I have had the car back for over a month now and have not had any more misfires. I read in other forums that the M270 and M274 engines had some faulty components at the manufacturing stage. In my case this was certainly not a software related issue. Service Advisor told me that piston rings were faulty and ended up damaging cylinder walls that had to be re-bored.

Good luck!
 

Registered
Joined
521 Posts
Discussion Starter #6
I had the exact same issue with my 2014 CLA 250. Started at 69000 km, had cylinders 3 & 4 misfire. Loss of power and strong vibration and CE light on. Then after shut down and restart, it would run fine and CE light would clear. First fix from dealership was to replace fuel rail sensor (covered under star cert. warranty). Car ran well for a couple weeks, then the misfire re-occurred. I took it back to the dealership, they ran compression test and found low compression and "scorching" in cylinders 3 and 4. They ended up having to send the engine block and cylinder heads to Toronto for repairs (apparently the only Mercedes certified machine shop in Canada). Total repair time took approx. 7 weeks. Fortunately repair and rental costs were covered under warranty. I have had the car back for over a month now and have not had any more misfires. I read in other forums that the M270 and M274 engines had some faulty components at the manufacturing stage. In my case this was certainly not a software related issue. Service Advisor told me that piston rings were faulty and ended up damaging cylinder walls that had to be re-bored.

Good luck!
Oh boy lol...this doesn't sound good. My issue so far is fine with whatever software fix they did. But I feel like my car jerks a bit more now from gears 1-3. Hopefully thats not a factor into the misfire issue.

Thanks for your information. Really insightful
 

Registered
Joined
521 Posts
Discussion Starter #7
Damn, looks like it happened again from Philly -> PGH...ugh. My warranty is almost over and this ofc happens right at the end after miles of reliable driving
 

Registered
Joined
9,851 Posts
I had the exact same issue with my 2014 CLA 250. Started at 69000 km ... Fortunately repair and rental costs were covered under warranty. I have had the car back for over a month now and have not had any more misfire ...
So you got your 2014 car back mar/apr 2019 ... extended warranty??
 
1 - 11 of 11 Posts
Top