Strange smoking 15 glk250
Thread Starter
Newbie
Joined: Feb 2025
Posts: 2
Likes: 0
Strange smoking 15 glk250
I have a 2015 glk250. Smoking constantly and found intake side of turbo some play and oily but not saturated. All exhaust head ports dry not wet with oil. Installed used lower mile turbo due to being a car lot customer and turbo supplied was from one of our long time suppliers.
Vehicle starts and runs fine. Idles normal and after 15 minutes in my stall could smell it getting a more pronounced “diesel exhaust” smell and slightly smokes. Drove and after 4-5 blocks smoking like crazy idle or accel. Tool back to my shop and idles and smokes. Very light grey and smells of oil and diesel fuel. Crazy thing turn car off and let set 20 seconds or so and upon restart will not smoke till I drive 4-5 blocks then cycle starts over. No codes and plenty of power.
I was advised possibly turbo drain… Any other things someone might have ran into to test come Monday?
Thanks so much for any ideas!
Vehicle starts and runs fine. Idles normal and after 15 minutes in my stall could smell it getting a more pronounced “diesel exhaust” smell and slightly smokes. Drove and after 4-5 blocks smoking like crazy idle or accel. Tool back to my shop and idles and smokes. Very light grey and smells of oil and diesel fuel. Crazy thing turn car off and let set 20 seconds or so and upon restart will not smoke till I drive 4-5 blocks then cycle starts over. No codes and plenty of power.
I was advised possibly turbo drain… Any other things someone might have ran into to test come Monday?
Thanks so much for any ideas!
Thread Starter
Newbie
Joined: Feb 2025
Posts: 2
Likes: 0
Member
Joined: Oct 2023
Posts: 109
Likes: 34
2015 GLK 250 Bluetec
I just reread your original post. You mentioned a pronounced diesel exhaust smell which could point to a fueling problem. It could be anything from a sticky fuel injector or a fuel regulator problem. Since the problem is intermittent, it does point to a possible electrical component in the fuel system.
Trending Topics
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
MBWorld Fanatic!
Joined: Jun 2021
Posts: 1,923
Likes: 522
From: New Hampsha
'17 GLS450, '14 GLK250, Grandpa's Roadster
MBWorld Fanatic!
Joined: Jun 2021
Posts: 1,923
Likes: 522
From: New Hampsha
'17 GLS450, '14 GLK250, Grandpa's Roadster
I think there must be a color perception issue. The only thing I can see that fits the symptoms is oil smoke, but that shouldn't smell like Diesel fuel, and is more bluish than just gray.
"White" smoke smells like Diesel fuel, but comes from a cylinder that is not firing, so power and idle smoothness will be affected.
"White" smoke smells like Diesel fuel, but comes from a cylinder that is not firing, so power and idle smoothness will be affected.
Last edited by John CC; Feb 10, 2025 at 10:17 AM.
MBWorld Fanatic!
Joined: Jul 2012
Posts: 1,369
Likes: 319
From: WI
GLK 250
Could be many things since we don't know the condition of the vehicle. I'm going to assume it's diesel fuel that's being burned causing the smoke, and since it goes away with a restart but comes back soon after, I'm going to go out on a limb and say it's possibly fuel being injected into the DPF (or where the DPF should be) in an attempt to run an active regen.
I would place the car on a lift, inspect the underneath and identify that all exhaust hardware that should be there is present.
In the meantime, don't start it on fire...
I would place the car on a lift, inspect the underneath and identify that all exhaust hardware that should be there is present.
In the meantime, don't start it on fire...
