Ammonia White Bluish Smoke?
Thread Starter
Newbie
Joined: Nov 2020
Posts: 4
Likes: 0
GLK250
Ammonia White Bluish Smoke?
Hey there,
Very strong and disgusting Smell and bluish smoke from exhaust at redlight or at stop sign?
i suspected def fluid so drained def and unplugged main tube which goes to exhaust from def tank to scr.
drove 2 hour city and highway was trying to dry exhaust system. No luck still same.
was monitoring live data through my phone as o2 sensor shows 350-400 celsius smoke and smell getting stronger.
any help im i on right path? Is def flooded whole exhaust system? Any advice?
Very strong and disgusting Smell and bluish smoke from exhaust at redlight or at stop sign?
i suspected def fluid so drained def and unplugged main tube which goes to exhaust from def tank to scr.
drove 2 hour city and highway was trying to dry exhaust system. No luck still same.
was monitoring live data through my phone as o2 sensor shows 350-400 celsius smoke and smell getting stronger.
any help im i on right path? Is def flooded whole exhaust system? Any advice?
MBWorld Fanatic!
Joined: Jul 2012
Posts: 1,369
Likes: 319
From: WI
GLK 250
If your AdBlue system is working properly, you will get the ammonia smell from your exhaust from time to time. The DEF is injected directly into the exhaust stream post-DPF to further scrub the exhaust of NOx gases.
I never noticed white/blue smoke, but I did get the ammonia small now and then. It's also possible when you last filled the AdBlue tank, you may have spilled some and it collected on the top of the tank, spilling over while driving. If it hits the hot exhaust pipes, you may get a stronger smell and possibly some smoke.
I would advise not overfilling your AdBlue tank. Wait till you get the "Low Fluid" warning, then add 5 gallons to the 7+ gallon tank. That way you won't over fill it and 5 gal should be enough to last another 10k miles or so.
If your AdBlue/DEF injector was faulty, you'd be getting error codes telling you about it because it can't work properly. If no CELs, you can worry less drive more.
I never noticed white/blue smoke, but I did get the ammonia small now and then. It's also possible when you last filled the AdBlue tank, you may have spilled some and it collected on the top of the tank, spilling over while driving. If it hits the hot exhaust pipes, you may get a stronger smell and possibly some smoke.
I would advise not overfilling your AdBlue tank. Wait till you get the "Low Fluid" warning, then add 5 gallons to the 7+ gallon tank. That way you won't over fill it and 5 gal should be enough to last another 10k miles or so.
If your AdBlue/DEF injector was faulty, you'd be getting error codes telling you about it because it can't work properly. If no CELs, you can worry less drive more.
Junior Member
Joined: Jul 2015
Posts: 41
Likes: 15
From: Las Vegas
2014 and 2015 GLK250
White smoke
This has happened a few times on my 2015. The first time I saw white smoke at 17,000 miles my particulate filter had become clogged and was throwing a 200200 code. The dealer replaced the particulate filter with a "remanufactured" unit. About 1,000 miles later I started getting white smoke from under the car which continued at the dealership (no CEL or codes). Looking under the car, you could see a drip from the DEF injector area and spray reaching the exhaust pipe. The dealer replaced the Ad Blue metering valve which I'm guessing was damaged during the replacement of the particulate filter.
A year ago, at 27,000 miles, I started getting white smoke out of the tailpipe again with an intermittent CEL light. The dealership found a P008A92 code which after troubleshooting led them to replace the low pressure fuel pump in the fuel tank. So, here are three different ways I've found my GLK can make white smoke. Good luck with your troubleshooting.
BTW, still love the car and my dealership. And the wife's 2014 GLK has had nary a problem with the Ad Blue system. Knock on wood.
A year ago, at 27,000 miles, I started getting white smoke out of the tailpipe again with an intermittent CEL light. The dealership found a P008A92 code which after troubleshooting led them to replace the low pressure fuel pump in the fuel tank. So, here are three different ways I've found my GLK can make white smoke. Good luck with your troubleshooting.
BTW, still love the car and my dealership. And the wife's 2014 GLK has had nary a problem with the Ad Blue system. Knock on wood.
