View Full Version : Black smoke

05-21-2015, 02:27 PM
My wife was recently on a trip with our 2006 sprinter and one morning it wouldn't start. She had it towed to mechanic in VA that says it's a turbo related issue. I'm not 100% sure of this, what we're seeing is when you turn the key over it trys to start and quits. The Scangauge is throwing a P0404 code (EGR) but the mechanic is adamant it's the Turbo. He did find the CAC hose had popped off so he put it back on and the van started. Upon getting it back to VT it wouldn't start again and the P0404 code is back along with some black smoke. What are the thoughts of the forumites???


05-21-2015, 02:49 PM
Black smoke means it's running rich. IE, more diesel than air.
1. Check for tears in the turbo hoses.
2. EGR valve has been known to make it run rich, too.
3. You may have an injector or two that are going south.

05-21-2015, 03:05 PM
It could be something turbocharger related, but your OM-647 5 cylinder engine does not need turbo boost
to start to run at idle speed.
Yes, lack of turbo boost would cause black smoke at higher RPM, but not at idle speed.
You can set your Scan Gauge II to MAP and tell very quickly if you have boost/MAP or not, but you will need to
get it running first.
So, the no start issues is definitely something other than the turbocharger.
You need to find a shop that can scan it for stored DTC's that your Scan Gauge II cannot discover.
Scan Gauge II is a good driving aid, but not so good as a diagnostic scanner.
See if you can find someone with a DAD unit, or take it to an authorized Mercedes Benz or Freightliner Sprinter dealer
(a commercial Sprinter dealer shop if you can find one.
Have you checked the battery voltage....if you've been trying to start your Sprinter without success, the battery will
normally be pretty low.
Check/Change the fuel filter.
Check all the turbo hoses just to make sure they are all connected and don't have holes in them.
Chances are the MB DTC codes stored in your ECM will show a major fault somewhere that's preventing
it from starting until the fault is cleared.
You cannot find this sort of faults with your Scan Gauge II!
You need a factory level diagnostic tool to read the stored codes.
Where are you located?
Some here may know of a good commercial dealer or an independent shop that has the diagnostics capabilities
near where your are located.
Hope this helps,

05-22-2015, 03:51 PM
I'm in northern Vermont. I did take the connector off the egr and the van started and ran so I took the valve off and it's pretty sticky. Took to work today and cleaned in an ultrasonic tank. Now to get back down to the van and try it. Fingers crossed. If all else fails I'll limp it to the shop and have them mess with it. Certified dealership 5 miles down the road. Just don't want to change the turbo if that's not the problem. Expensive test.

05-22-2015, 04:08 PM
"Change the turbo" seems to be the mantra of many Stealerships. Along with the turbo, they swap out other stuff, too. Sort of a "birdshot" approach.
Replace alot of stuff and one of them may be the culprit. There have been very few actual turbo failures here on the forum.