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thomasguy
Active Member
Canada
21 Posts |
 Posted - 10/08/2007 : 3:43:14 PM
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Hello Everybody,
Glad to be here, this is my first post and it's a head scratcher...
We Just purchased four 2008 Thomas C2 School Buses with the new Closed Crankcase Ventilation System and Exhaust Regeneration System from Mercedes.
Any time during the bus run the operators are complaining about white smoke coming out from under the hood. The regeneration system amber light flashes on momentarily, we know that there is a diesel feed system that heats up the exhaust system to very high temperatures to clean out the soot build up.
We have come to the conclusion that the white smoke is the unburned diesel fuel that accumulates during regeneration but can't seem to find the exact spot where it's coming from.
Everytime a couple of the techs take it out for a long test drive the smoke problem never happens, so we're going to send a Mechanic with an operator on his run and remove the heat shroud from around the starter [the smoke was seen coming from that area by an operator].
I was just curious if anyone else is experiencing this same problem, and hoping some feedback will help. The dealer knows about it and there are other School Districts in BC having trouble as well. The buses are still safe, it just presents a problem when passengers or the public notice the smoke.
Thanks,
John  |
Edited by - thomasguy on 10/08/2007 3:50:04 PM
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thomasguy
Active Member
Canada
21 Posts |
Posted - 10/09/2007 : 10:06:41 AM
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So we have concluded that the white smoke is coming from the turbo housing during regeneration, one of the operators pulled up this morning and the smoke was very obvious. We took the buses to the Mercedes dealer and they have witnessed the smoke as well so it's in their hands.
I'll let everyone know when a solution is found.
John |
School Bus Maintenance & Repairs.
http://schoolbusmechanic.blogspot.com |
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thomasguy
Active Member
Canada
21 Posts |
Posted - 10/10/2007 : 10:07:11 AM
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The Mercedes dealer has informed us that there is a valve called a "Doser Valve" which is located just past the turbo and is not atomizing the diesel fuel properly during regeneration. So raw fuel is seeping past the clamp on the exhaust piping and creating the white smoke from hot running temperatures. We will wait and see what develops.
By the way I'm not trying to make a negative issue out of this situation. I just want to keep fellow C2 owners informed, we are very happy with the Mercedes MBE 900 and realize that new technology is unpredictable.
John 
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School Bus Maintenance & Repairs.
http://schoolbusmechanic.blogspot.com |
Edited by - thomasguy on 10/10/2007 1:24:39 PM |
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thomas86_a
Top Member
USA
4413 Posts |
Posted - 10/10/2007 : 10:28:01 AM
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| Thanks for the updates! |
If you have an International, you NEED customer service. |
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dbarmaster
New Member
1 Posts |
Posted - 10/14/2016 : 08:58:19 AM
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| what did the dealer find ? |
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baptistbusman1
Senior Member
USA
175 Posts |
Posted - 10/14/2016 : 6:57:41 PM
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| 9 years later, and I have to say I absolutely hate these engines.....check engine lights on constantly with EGR's, Turbo Actuator's, clogged DPF's, DOC temp too high, turbos blowing oil. Wish I had never seen these things. |
I was formally Baptistbusman. However, I lost my password, and had not updated my email address.
Here is a link to my old posts. http://www.schoolbusfleet.com/forum/search.asp?mode=DoIt&MEMBER_ID=1846 |
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C2 White Smoke Coming From Under Hood
