.png){kind=logo}
There is no odour within the vehicle, but the exhaust gases from the tailpipes give off a distinct odour. The odour of my exhaust fumes is much stronger now than it was before. I only notice it when I'm outside the car with the engine running or as I reverse through the fumes.
Enjoyable power, drivability, and gas mileage with no warning lights appearing. I wonder if my O2 sensor is on the limit of acceptable, not enough to throw a code but enough to make the car slightly lean or rich and affect the smell of the exhaust smoke....but thats a bit of a guess....until recently I'd never even noticed the exhaust smell.
Have you any suggestions? Many thanks.
You’re only seeing the surface.
Our most active car forums and technical guides are reserved for registered users.
Sign up here to get total access and start sharing your own ride.
Our most active car forums and technical guides are reserved for registered users.
Sign up here to get total access and start sharing your own ride.
Gaseous OM642 emissions have an unpleasant aroma.
-
franchcars
- Posts: 41
- Joined: Mon Feb 02, 2026 8:38 pm
Has your recent anxiety over the car put you on high alert for any problems, and are you sure this isn't merely subjective? Most diesel exhaust emissions always sound quite pongy to me.
-
Hughes-Davies1979
- Posts: 45
- Joined: Mon Feb 02, 2026 8:47 pm
Definitely a greater odour than before; even Mrs. Ai noticed it, and she usually doesn't pay attention to car problems until they break.
-
lumperjack
- Posts: 48
- Joined: Mon Feb 02, 2026 8:51 pm
Approximately how many months has this problem persisted? You must have occasionally detected the odour of DPF regen, right? Find out how often the car currently regenerates if it's the same or comparable.
The intake manifold on my old OM612 was always moaning and the engine always had a terrible odour when cold started. The engine's seals closed up when it warmed up, and now there's no more whine or smell. Additionally, make that there are no boos leaks; as you likely well know, it can be a real pain to locate a split boost hose, especially if the leak isn't big enough to set off an alarm.
The intake manifold on my old OM612 was always moaning and the engine always had a terrible odour when cold started. The engine's seals closed up when it warmed up, and now there's no more whine or smell. Additionally, make that there are no boos leaks; as you likely well know, it can be a real pain to locate a split boost hose, especially if the leak isn't big enough to set off an alarm.
-
Hughes-Davies1979
- Posts: 45
- Joined: Mon Feb 02, 2026 8:47 pm
Not sure, maybe the past two weeks. The only "smell" I catch when I come to a stop during a regen is the increased heat from the over 600 degree DPF, not the exhaust, because I normally drive during these periods. It would surprise me if there were any leaks, but I will check.
-
LiamTheGreat
- Posts: 79
- Joined: Mon Feb 02, 2026 8:35 pm
As I've never detected any exhaust odour coming from our OM642, it seems like something has evolved.
-
zafershoukat3109
- Posts: 45
- Joined: Mon Feb 02, 2026 8:46 pm
When it becomes hot, does it do it? The egr bypass is closed while the engine is cold so that hot exhaust gases can pass through and help the engine warm up faster.