Cummins ISM in Monaco coach

[Hokiefyd]

My folks are full-time RVers and they have a 42' Monaco Dynasty with a 400 horse version of the Cummins ISM. The model year is 2004 or so and they have 80-100k miles on it as I recall.

Dad's having a problem with the oil level that neither one of us can figure out. Just on their past trip of about 1,000 miles, he "made" about 2.5 gallons of oil in the sump. He has a 1 gallon crankcase overflow system on it and that is full; his sump has an extra gallon in it, and the Jeep they tow behind it has oil on it. This has been occuring for a while, but he thought the engine was just being overfilled by Speedco (where they usually have the oil changed).

He always uses Shell Rotella T. He gets the oil analyzed every few oil changes and the viscosity is perfect every time (in the 14.5 cSt range). The flash point is always normal (I don't recall the number). There's no real fuel dilution noted in the UOAs either.

Anyone out there familiar with this engine family? What could be causing this type of "sump overflow" when driving? And more particularly, what could be causing it and also NOT show up on a UOA?

Cheers!
Jason

 

[scurvy]

Sump overflow in a diesel typically means very bad things because it's usually caused by fuel dilution! You've got a massively leaking injector, holed piston or busted rings going on.

Strange that the viscosity, flash point & fuel dilution aren't affected which points to it NOT being a fuel leak...

 

[skellyman]

The new "tech" at Speedco is overfilling the engine.

 

[Hokiefyd]

The engine has also been dyno'd a number of times and puts about 330 hp to the wheels. That's probably about on-par for putting 400 hp to the crank. They've also done "blowby testing" on it (a Cummins dealer) and all is "within spec".

 

[Hokiefyd]

Originally Posted By: skellyman
The new "tech" at Speedco is overfilling the engine.


The oil level was correct before their 1,000 mile journey, and is now 2+ gallons surcharged. I would think it has to be fuel, but I'm not sure where it'd be coming from, and I'm not sure why it wouldn't be showing up in UOAs.

 

[Chris142]

the seals that seal the injectors to the heads are leaking. commonly called "coppers". it needs to be towed to a shop ,not driven asap.

 

[lt1man]

Let's not freak out here. Send in another UOA to a different lab and explain the situation, or even Cummin's can do a UOA on site I believe. THere must be a logical explanation for it.

 

[skellyman]

Originally Posted By: lt1man
Let's not freak out here. Send in another UOA to a different lab and explain the situation, or even Cummin's can do a UOA on site I believe. THere must be a logical explanation for it.

Agree !! do another UOA An quick.

 

[440Magnum]

Its not clear from your original post that a UOA has been done AFTER the engine started "making" oil. I'm betting one done right now would show fuel.

I'm not familiar with the details of the ISM, but my gut says that its a fuel leak something like what Chris142 describes. The mechanical failures as bad as Scurvy suggests are possible, but I would think your father would notice a drastic difference in the engine's performance. An injector delivering too much fuel to one cylinder certainly shows up at idle on a diesel- one cylinder pounds at high power wile the others get carried along. Heard an old beat-to-death Navistar doing that next to me at a traffic light the other day.

 

[Food Scientist]

Did you smell the oil? Usually with massive amounts of fuel dilution you can smell the diesel fuel.

 

[skellyman]

Originally Posted By: 440Magnum
Its not clear from your original post that a UOA has been done AFTER the engine started "making" oil. I'm betting one done right now would show fuel.

I'm not familiar with the details of the ISM, but my gut says that its a fuel leak something like what Chris142 describes. The mechanical failures as bad as Scurvy suggests are possible, but I would think your father would notice a drastic difference in the engine's performance. An injector delivering too much fuel to one cylinder certainly shows up at idle on a diesel- one cylinder pounds at high power wile the others get carried along. Heard an old beat-to-death Navistar doing that next to me at a traffic light the other day.


Agree , just when was the UOA done an by whom ??

 

[Hokiefyd]

This engine has been "making" oil for a long time. Like, years. He's always thought that the crankcase keeps getting overfilled, but since he's started to pay more attention to it, he's realizing that the engine is "making" this oil. I did ask if he smelled the overflow system he has and he said that it didn't have a particularly heavy smell of fuel. I think the latest UOA was just a few months ago, but either way, he's been having UOAs done for most of the time they've owned the coach, and it's been "making" oil for most of the time as well.

Engine performance hasn't changed (and it dyno's at full power), fuel mileage hasn't changed (it gets about 8 mpg), and nothing else seems out of the ordinary. He has previously sent me the UOAs. I will post them tonight.

Thanks for the help so far.

 

[Hokiefyd]

Originally Posted By: skellyman
Agree , just when was the UOA done an by whom ??


All of the UOAs have been done by SpeedCo, using their on-site analyzer. They are a nationwide heavy truck maintenance facility.

http://www.speedco.com/Speedco-Truck-Lube-LubeTrack-Oil-Analysis-Services.html

 

[skellyman]

Might just send a sample to another lab, could be the same tech who is filling the engine is also reading the results of your UOA, maybe they're not well trained ?

 

[Hokiefyd]

Here is the UOA history:

BITOG thread

These were done at various SpeedCo locations across the country.

 

[mahansm]

I'd take a look at the injection pump. If it's a piston type injection pump, the lower end will be lubricated by engine oil and drain back into the sump. Any leakage will also be directed to the engine sump. A leak here will not affect cylinder balance or power output.

 

[07Wolfie]

It is mysterious, but then again it's not. Leaving the fuel economy, dyno results, engine sound, and everything else aside, if you've positively established that the oil level is actually rising as the engine runs, then something is displacing the oil- it's either coolant or fuel, regardless of whether or not it shows up in UOA. Either way it's not too good but maybe you can correct it before it does more damage...

 

[dnewton3]

When someone gets bad news from the doctor, they should always go for a second opinion, from a unrelated source. Asking Speedco over and over again may not be getting your partents the correct answer. Get another opinion from a separate source. Many good labs to choose from, but I'd ask if you'd consider supporting our site sponsor, Blackstone.


All that aside, I somewhat agree with Wolfie above, except for his terminology. Fluid "displacement" means something goes in for something going out (one thing displacing the other). In that sense, the oil level would stay constant. I say this; if the oil level is rising over the OCI, then something is ADDING to the overall volume of the lube system (not displacing it). Might be fuel, might be coolant, might be a bit of both. Like I said, I agree with him in concept, except that the fluid level would not be increasing with "displacement".

I looked over the series of UOAs you posted for this rig. TBN seems really strong for some really varied runs. I don't know that there is much consistiency overall, though. I'll not make detailed comments on the UOA here, except that I'll note they say less than 2% fuel and no water/coolant intrusion.

Get a good UOA from a separate source. Given the sump size of the ISM, I'd ask to take a sample of the virgin oil for reference. Then, check the oil level every 1k miles; log the volume change. At perhaps 3k miles, get a UOA on the oil, and compare/contrast to the VOA.

Let's look at this logically:
Something is wrong. You cannot have your cake and it eat too. There is no logical explanation of having a series of acceptable UOAs AND a rising sump level. They cannot coexist! Something is adding to the sump volume, and it has to be either fuel or coolant (or both). Or, the rising level is imagined. One or the other, but not both at the same time.


Get a second opinion from a separate lab.

 

[slammds15]

I also find it odd that the UOA's do not show fuel. Possible cause include:

-Excessive idle times
-Upper Injector o ring is damaged or injector timing plunger is damaged.
-Injector adapter wall is damaged behind the balance orifice
-Injector cup is cracked or damaged
-Fuel pump gear pump main shaft seals are leaking
-Cracked or porous cylinder head

I have replaced several pumps due to the seals leaking, rarely have the other cause listed been an issue.

I agree with dnewton3 about getting a second opinion.

 

[slammds15]

28.5 to 34 standard automotive and 30 to 34 for transit regarding oil capacity. There are several oil pan configurations depending on make/model of vehicle and application.