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Cummins M11 missing and smoking

Wes J

Senior Member
Joined
Jan 24, 2016
Messages
649
Location
Peoria, IL
Cummins M11/ISM (it's a 2003, so not sure which it is) in an International dump truck.

Engine starts really hard. Probably cranks a good 10 seconds before it fires up. Start up gives a good puff of smoke.

On acceleration it stumbles and misses, especially around 1,100-1,250 RPM. Loaded it will miss a bit at any RPM when accelerating.

The smoke looks more blue than black to me. That seems very odd.

IMO, it does not have the power it should have and uses more fuel than I think it should.

Complicating the issue is a variety of electrical problems that have been either cause by, or not fixed by, the customer. Cooling fan runs all the time. AC clutch runs all the time and appears to have been hot wired to a switch in the dash. Turning off switch kills AC, but not the fan. Most HVAC controls don't seem to work at all. Starter relay has been cooked right out of the relay panel. Customer installed a push button instead of fixing (probably cooked due to long start time, I know they also replaced the starter recently).

Any thoughts? Customer swears it's a computer issue. I guess it could be. No lights on on the dash. To me it seems like a fuel pressure issue or possibly an air leak in the fuel system.

The blue smoke seems odd. I don't know if it's burning oil because it leaks so much (about a gallon a day). Turbo seems to be working OK.

They probably won't fix it, but thought I would ask.
 

DMiller

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Hermann, Missouri
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Blue smoke, engine miss, lack of power point to either a bad piston or rings on at least one cylinder, maybe losing a injector where the fuel has washed out a hole would combine for loss of residual fuel start pressure and the damage left behind.
 

Wytruckwrench

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Jul 22, 2012
Messages
270
Location
Wyoming
First, I’m going to say run away from this consumer. They are not a customer or a client. Just cobblers. I would start with checking exhaust manifold temps on a cold start. See what the difference is across all six, then compression test and make a plan from there.
I seriously doubt there’s a computer problem.
 

John C.

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Northwest
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A few pieces of information that I like to get when and engine issue comes up. How many miles or hours are on the unit? How much blow by or vapor is coming out of the breather tube if it has one? It there are lot of oil all over the motor?

One comment is that I get aggrevated when the customer comes in a tells me what is wrong and what to fix? If they knew that much already they wouldn't have brought it to me in the first place.
 

Wes J

Senior Member
Joined
Jan 24, 2016
Messages
649
Location
Peoria, IL
430,000 miles. That's long in the tooth for a dump truck.

Front cover leaks really bad at the bottom corner. I can see silicone squeezed out of the oil pan gasket, so somebody has hacked that.

Not sure how you do a compression test on a unit injector engine.

Probably right to run away. The rest of the truck is not much better than the engine.
 

ETER

Well-Known Member
Joined
May 31, 2015
Messages
158
Location
Upstate New York
'03 would be an ISM...if you don't have a "dead" skip... then exh. manifold port temps at start- up won't tell you anything (will not be enough variation...unless an injector is "over-fueling"). Does the check engine lamp cycle at "key-on"? (lamp may be inop.) Regardless, it's an electronic engine so you need to look at fault code history before putting wrenches to it (let the computer tell you if it's sick). Could be something simple like poor grounds (injector drive modules need good grounds!), or maybe it's pulling air? (would explain smoke / hard start).
Regards, Bob
 

Truck Shop

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Wes-it sounds like a disaster looking for a place to happen. I doubt the overheads have been adjusted in forever. Blue smoke-possible turbo seal or any number of things.
And more than likely the injectors are very tired. Sounds like a turd that survived the flushing-do your self a favor walk on by. It's just another M11.

Truck Shop
 

funwithfuel

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Mar 7, 2017
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Will county Illinois
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Mechanic
I'm just gonna figure that you'll tackle this job anyway. The first thing I would look into, is whether or not the valve cover has been off. Does it have Jake's or C-brakes? If it does, get em off and plug the feed holes. While you got that cover off, run the overhead. Make sure you have lash at each rocker, or can establish lash. If you've got a rocker that won't give lash, you probably failed a valve . Adjust injectors on obc method. Which means valves and injector on same timing mark, torque injector to I believe 70 INCH pounds. Been a while since I've had one open. I like torqueing the injectors rather than the touchy feely 6 inch pound bs of inner base circle. More consistent results. If simply running overhead clears things up. Win! Oh, while you're under the valve cover, check injector harness pass through at rear of rocker box. Sharp bend there causes chafing in harness.
If you popped off the Jakes , go through them on the tailgate. Check springs, plungers, solenoids and o-rings. If you got a lazy solenoid, you're gonna have a shitty running engine with no error code. Hell it won't even register a misfire.
Good luck whichever path you choose.
 

Wes J

Senior Member
Joined
Jan 24, 2016
Messages
649
Location
Peoria, IL
What the hell does the ac have to do with the engine missing and starting hard

It's just background info suggesting that the truck has various electrical issues and has been hacked together.

No engine brakes. No idea on the past maintenance. Probably none.

Maybe a box of matches or a stick of dynamite...
 

ETER

Well-Known Member
Joined
May 31, 2015
Messages
158
Location
Upstate New York
I think that the L10, M11, ISM family of engines were a good line of engines... someone will correct me if I'm wrong, but I think the m could be turned up to like 430 horse!
If it was an L10 with 400k, then it should have had injectors thrown at it a long time ago... being an ISM maybe, but you really should rule out the obvious and check for codes, put on your detectives cap and check for fuel pressure / restriction / air inundation. Injectors are adjusted on the OBC, but I always turned them in all the way and backed out 2 flats after the valves were set. It would bug me not to know why it's not running right. The hard start issue is probably 90 percent of the runnabilty problem. Fix the thing!
Regards Bob
 

Wes J

Senior Member
Joined
Jan 24, 2016
Messages
649
Location
Peoria, IL
Once it stops running all together they'll want to fix it. Or maybe they'll park in out on death row with the other rigs they never fixed. I've got my eye on an R model Mack with a 12 speed that supposedly needs a cam. I bet that's not all it needs...
 

DMiller

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Have seen that type of 'Maintenance' practice over and over for years. They change their oil as they see fit not when needed, they do no regular tunes or base line inspections under the covers or around the machines, they run them into the ground then whine like little girls when the estimates come out to bring to anywhere near to functional again.
The owner I drive for has accepted Schaeffer oil analysis as a bottom line saver, he has extended his oil change intervals out to almost 30,000 where the engine shows its distaste by growing consumption rate toward the 20,000 mile mark. At 10k will use little oil less then a gallon, at 20k is using just over a gallon to 10k when comes due to change has begun to use almost 2 gal for that last 10k. Cannot imagine what that will look like internally at another 100,000 miles. I took a sample to CAT for a independent sample at 15k, was in that analysis it needed to be changed, acid levels up, copper and iron up, not good.
 

funwithfuel

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Will county Illinois
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Worked for a fleet back in late 80's . They ran synthetic oil and based oil change intervals as DMiller stated above. They would always brag about how many miles they got on their oil drains. In one year they lost 3 bottom ends. 2 CH613s & an R686ST. Pulled the valve covers. It was horrible. We had to chip the crust, soot and Ash away to see the poor rockers. I speculated that the oil was getting trapped everywhere but returning to sump.
Well I was young n dumb at the time. But seeing that turned me off the whole idea of extended drain intervals for the rest of my life.
 

Truck Shop

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The true problem with rigs like this one. Lets give it a full/jack it up inspection king pins and all. It has more than a poor running engine, most likely needs suspension work,
brake work, steering gone through, air leaks repaired and electrical repaired. Engine gets repaired but screw the rest-D.O.T. mans dream.

Truck Shop
 

RZucker

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Wherever I end up
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The true problem with rigs like this one. Lets give it a full/jack it up inspection king pins and all. It has more than a poor running engine, most likely needs suspension work,
brake work, steering gone through, air leaks repaired and electrical repaired. Engine gets repaired but screw the rest-D.O.T. mans dream.

Truck Shop
Yep, seen too many of these types... "Get out of my yard", I have enough work with well cared for trucks. I guess I'm just getting old and don't need the headaches.
 

Wes J

Senior Member
Joined
Jan 24, 2016
Messages
649
Location
Peoria, IL
I dunno. I'd say this is about in line with other local dump trucks. They mostly run state roads, no scales, just dealing with local cops. They have to have a state inspection every year, but they let you by with a lot. As long is it has some brake pad left and the frame's not cracked, they'll take your $30 and give you the sticker.

I'd wager every tandem dump truck in the state would fail a real DOT inspection at any given time.

Same for the grain haulers. Most of them run mileage plates, so they drive less than 7,000 miles a year.

But, just at a glance, here's the short list:

Power steering weak, steering wheel not centered, so someone has been into it.
ABS light on
Rubber pad suspension is probably worn out. Of course, even brand new they ride like crap.
Hoist cylinder leaks pretty bad.
Aluminum tailgate and box has many cracked welds.
Mirrors bounce and shake all over.
I can probably move the shift lever 6" in any direction while its in gear. Needs a shift tower and isolator bushing.
Bostrom seat needs bushings.
Tarp barely works.
Needs a clutch brake.
AC issues as mentioned.
 
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