Looking for a diesel guru

[Doug_E_]

I had just filled up our mh with 70 gallons of fuel, from the Pilot truck stop in Madera CA.
I Drove to Stockton, with my daughter's in-laws following in their mh. When we arrived, I was told the mh was blowing black smoke, (more than usual) but only when we went up overpasses, all the way to our destination. I had not noticed any black smoke, nor had had I noticed any appreciable difference in performance, or fuel mileage. The MH ran good as always on the trip home
Just in case, I changed the fuel filters this morning, and cut the old filters apart, I saw nothing inside like allege, or any dirt.
I'm wondering if I should take the mh into Cummins West and have them check it out, or just wait and see what will happen, the next trip out.
As a side note, the wind was probably blowing @ 8 - 10 mph of head wind, and pulling a 24 ft. enclosed race trailer weighing 6000 lbs.

[Doug_E_]

Hi Ken,
I had purchased and used the PacBrake oil before.
When I talked to Dave at Cummins West, he asked if the MH had set for awhile, when I told him it was not in service for 3 months, he said sometimes the PacBrake will stick for awhile.

Hi Brett, thanks for the link to the page on lube points on the PacBrake, I believe I had lubed all of the points but I'm going to recheck in the morning.

Thanks again to the forum and all who responded with suggestions of help.

[wolfe10]

n4hwl wrote:
Doug

What did you oil the exhaust brake with? I think I read that you are suppose to use some type of high temperature oil on it. I bought some Pac brake brand oil somewhere that was for this application. It may be all advertising about the pac brake oil. I thought I would just ask.

Ken

http://www.pacbrake.com/index.php?page=maintenance-2

[n4hwl]

Doug

What did you oil the exhaust brake with? I think I read that you are suppose to use some type of high temperature oil on it. I bought some Pac brake brand oil somewhere that was for this application. It may be all advertising about the pac brake oil. I thought I would just ask.

Ken

[Doug_E_]

Ok, for what it's worth.
I must have scared the heck out of her, (was going to leave her all by her self all weekend at Cummins West).
Hooked up the Jeep and was headed into town, to have her checked out.
On the way there, I noticed a different exhaust tone, then she started running just like always, 32 lbs. of boost too.
The only thing I can figure, the exhaust brake must have stuck part way closed.
Anyway, it's nice to have her running on all 6 again.
Thanks for all of your suggestions, never know one of them might have helped.

[Doug_E_]

The check engine light never came on.
Other than a little slower take off from a dead stop, and some black smoke out the exhaust pipe, I think she still runs great.
When I find out what the damage is, I will post here.

[keepingthelight]

Did your check engine light or ECM light come on indicating a problem?
May want to have that scanned first. If you are sure your boost has dropped slightly, this could indicate a bad injector, loose turbo hose or an issue with the turbo or exhaust brake staying open. Better have Cummins troubleshoot, we are only amateurs;)

Keep us posted

[hone_eagle]

Doug E. wrote:
If I recall correctly, the boost guage used to register 32 lbs. of boost, now its hard pressed to reach 24 lbs, of boost.
I've tried everything, all of the members on this forum have suggested.
I think it's now time for some professional help.

You did all you could do ,the black smoke is fuel injected into a insufficient supply of oxygen
if there is no discernible hose or boot leaking you have to consider the CAC is losing pressure,
could cost a bit.

[aztortuga]

Doug, do let us know what the diagnosis and outcome is.

[Doug_E_]

If I recall correctly, the boost guage used to register 32 lbs. of boost, now its hard pressed to reach 24 lbs, of boost.
I've tried everything, all of the members on this forum have suggested.
I think it's now time for some professional help.

[tinkerer]

One other thing to check is the connections on both sides of the turbo. Does this coach have turbo boost pressure somewhere in the instruments? I have a Freightliner chassis and you can scroll through the reading on the instrument panel and it will bring up the turbo boost. I use it all of the time as with this reading I can tell how much load the engine is under. 😉

[Doug_E_]

Well, I tightened all of the spring clamps, oiled the exhaust brake and took mh for another test run.
It still blows black smoke for about 2 seconds after I start to accelerate, the boost guage indicated about 25 lbs of boost (which I think is a little low)I thought it used to go way past 30 lbs. of boost.
If I can not find anything else, I have an appointment with Cummins West for next Tuesday.

[shaneperch]

RayChez wrote:
Lots of black smoke means a bad injector.

YES that is exactly where to look before going into turbos and scaring yourself with "what ifs"

[wcjeep]

Boost leak at either boot or the boost line that goes to the waste gait.

[glamisorbust]

I drove truck for years, and a few of them were heavy haul/oversize. I have plenty of experience and a ton of miles and fuel burnt under my belt. I had a kenworth with a cummins 400 and 13 speed for my last truck. I drove that particular truck for 2 years almost trouble free. One time, it started losing quite a bit of power, and when I stopped and got out it was smoking like a freight train from the 1800's. Made the truck completely un-driveable, it wouldn't boost at all. It ended up being the wastegate on the turbocharger seizing up, not allowing boost pressure to build and be forced into the intake. They replaced the wastegate and the truck ran perfect again. I seriously doubt it's an injector or anything else.