Oil Consumption/Crankcase Pressure Diagnosis

Zachary Mobile Technician Austin, Texas Posted   Latest   Edited  
Question
Driveability
Heavy Duty
2012 International 4300 7.6L (MaxxForce DT Diesel)
Excessive Oil Consumption & Crankcase Pressure

VIN: 1HTMMAAM3CH436007 Mileage: 167,682

Good morning all. One of my fleet customers owns this truck which recently began experiencing excessive oil consumption. Truck was originally a Penske box rental and was converted to a dump truck for the customer's use. Last week they started having to add approximately 2 quarts of oil each day they used it. Up till then they weren't experiencing any loss of oil. (Fluids are checked everyday before operation of their vehicles.) They didn't notice any drips or smoke in the exhaust and asked me to have a look. I quickly discovered what appeared to be excessive crankcase pressure when I ran the engine with the dipstick removed. I included a video of this at idle. When the engine speed is raised, the smoke dissipates. Long story short, I immediately wondered about the breather system on this engine. After reading in the service manual, I discovered that it uses some kind of oil pressure driven centrifuge assembly. The only test they list for the unit itself is to shut off the engine once warm and listen for the high pitched noise from the separator. This supposedly indicates the centrifuge is working. You should hear the noise for approximately 15 seconds following shut down. I did so and didn't really feel like I heard anything, but I don't have a known good to compare it to. I'm hoping to get some insight here before proceeding. I figured an oil pressure check at the supply line to the breather would also be a good idea. I used a stethoscope as opposed to the ultrasonic ear the manual calls for but I assume it should be more than capable of picking up this noise. My tooling and resources are limited for heavy trucks but I do like a challenge. Thanks in advance for any and all input here. Hope everyone is having a great week!

Quick update on informatio: I repeated the stethoscope check once I had the engine a bit warmer, and I can definitely hear this thing spinning down once the engine shuts off. I do wonder if it's possible for the pieces inside to break apart and not work correctly but I hate to start tearing this thing apart without good evidence. It may be that this engine has excessive blow by but I find it odd that it happened so abruptly.

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Dick Owner/Technician
Forsyth, Georgia
Dick Default
 

Take the hose loose from the turbo to the air to air system. You will probably find oil in there indicating bad turbo seal.

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Michael Business Development Manager
Las Vegas, Nevada
Michael Default
 

does it have a CCV system?

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Yes it does Michael. Uses a version I've never seen before. Has an oil pressure driven centrifuge inside the breather that slings oil to the side and allows it to drain back to the crankcase. Both of the turbo oil drains also route through here. Apparently the centrifuge can stop and cause excessive crankcase pressure.

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Zachary Mobile Technician
Austin, Texas
Zachary Default
   

Dick I did remove the charge air cooler pipe and there is oil there but I'm concerned about this crankcase pressure. I pulled the inlet elbow off of the compressor side of the turbo as well and there was oil there too. Didn't feel excessive play in the shaft but the breather outlet sits right in front of the turbo inlet. That's not to say the seal on the turbo isn't bad. I just want to make sure…

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Dick Owner/Technician
Forsyth, Georgia
Dick Default
 

The turbo may be sucking oil from the air compressor lube circuit. Take the Air compressor discharge line loose from the air dryer and see if oil is present. Would indicate a bad air compressor.

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Surprising as it may seem this one actually has hydraulic brakes. I don't believe there's an air compressor on it for anything else but I'll double-check. Thanks Dick.

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George Owner/Technician
Skagway, Alaska
George Default
 

Most of the ones I work on have a parking brake that is air. I have a fleet of these and only 1 has manual parking brake. The rest have air operated parking brakes. How much blow by is coming out of the oil filler tube?

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Hey George. This one has a manual parking brake on the drive line. It's a decent amount of blow by from the filler tube. You can see it in the video I posted. I had to leave there but want to take a crankcase pressure reading when I go back. If you raise the idle speed the smoke goes away which is why I was curious about that oil separator. Thanks for your input.

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George Owner/Technician
Skagway, Alaska
George Default
 

I figured you had already checked it but just mentioned it to be sure . Sorry I couldn't be more help.

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

No apology necessary George. I really appreciate your input. Never hurts to ask because we all forget the basics at times. I've certainly missed something I should have caught early and kicked myself for it later.

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Dick Owner/Technician
Forsyth, Georgia
Dick Default
 

Bet you find a busted ring or related type problem on a single cylinder

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Gordon Technician
Moncton, New Brunswick
Gordon Default
   

What you're likely looking at is a failed crankcase breather mounted low on the RF of the block. Yours most likely is a closed crankcase system such that the outlet doesn't go to a road-draft tube but goes back into the intake just before the turbo inlet. When failed oil is not seperated and drained back to the sump, it is passed to the outlet and into the LP turbo...which of course then gets…

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Zachary Mobile Technician
Austin, Texas
Zachary Default
   

Thank you for all that information Gordon! I assume just a cam sensor for that particular engine is what you'd want? Pretty nice they eventually added that to the breather itself for diagnostic purposes. Seems like an important piece of information. I'll look into that test and see where it leads me. I saw something mentioning that modification kit. Is it straight from International?

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Gordon Technician
Moncton, New Brunswick
Gordon Default
 

Howdy Zach - sorry about the delay responding - yep on the cam sensor. Attached is the iKnow article detailing the breather mod and the crankcase breather speed test using a multimeter (which measures frequency)

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Hey Gordon - No problem at all. I really appreciate your input on this. I will most definitely put that information to good use when I'm back out there on Thursday. I figured frequency but appreciate the clarification on that. Happy holidays to all!

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Victor Owner/Technician
Doral, Florida
Victor Default
 

Install a catch can and be done with it.

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Michael Mechanic
Montgomery, Texas
Michael Default
 

Double check your fuel tanks and rule out the oil being lost into the fuel system... if so fuel will be really nasty looking... only takes a few seconds to rule out.

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Michael that's a good point. I hadn't thought about that. Failed or damaged o-rings on the injector allowing it into the fuel passage I assume?

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Rex Technical Support Specialist
Alliance, Ohio
Rex Default
 

Get an oil sample ASAP. Look for aluminum and iron content. The 2010 and up engines have a problem with aluminum flaking off the EGR crossover tube at the back of the engine and the mixing box where the EGR valve goes and the intake manifold. Puts aluminum into the engine thru the intake and takes out the cylinders. This will raise crankcase pressure. The spinner setup causes the problems that…

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George Owner/Technician
Skagway, Alaska
George Default
 

Where can I find more info on converting these to an open breather system. I have a fleet of these that only see low speeds and run all day.

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Rex Technical Support Specialist
Alliance, Ohio
Rex Default
 

George, your dealer can find that out. In some case you may have to pull the tube off at the valve cover to confirm which valve cover is on it. If you through some VIN's up I can look. I will post more later. There is a regen inhibit feature that is also useful if the drivers aren't idiots.

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George Owner/Technician
Skagway, Alaska
George Default
   

The key word is if the drivers aren't idiots...........I won't see this fleet again until at least April. I work seasonally in a tourist town. 6 months of six 12 hour days. 6 months of roll up the sidewalks and no work. Thanks for the info

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Rex Technical Support Specialist
Alliance, Ohio
Rex Default
 

Also in 2004 the injector design changed. High pressure oil now goesinto the top of the injector thru a manifold. Different from the HEUI design. Almost impossible to get oil into the fuel system. Would have to be an internal injector failure. Anything that bad would likely have a miss.

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

That's great information Rex thank you for your post. I'll make sure to collect an oil sample as soon as possible. Also makes sense what you're saying about the injectors. Had to replace the number 3 unit in early July for a solenoid fault and saw that manifold. Very similar to the VT365 engines post early 2004. Excellent little tidbit about the piston rings too.

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Michael Diagnostician
Champaign, Illinois
Michael Default
 

Hi Zachary does this unit have a crankcase pressure sensor? If so maybe you could graph it with Turbo speed and see how it reacts as the unit smokes and then goes away. Just a thought. That might help you get in the right direction.

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Hey Michael, thanks for suggestion. I didn't see one previously but I'll double-check. The other issue there for me is I don't yet have proper scan tool coverage for these trucks. On my list but an expense I haven't yet been able to incur. I'll be back out there early next week and have the equipment to do the breather speed test. I'll let everyone know how it turns out.

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Zachary Mobile Technician
Austin, Texas
Zachary Update
 

UPDATE Good morning all. Hope everyone had a safe and happy holiday season. Don't have a definite resolution to this one yet but wanted to give an update. I have the opportunity to spend a little time with the truck on Tuesday and this is what I know additionally. When I started it up dead cold it sounded kind of rough which led me to question mechanical integrity. I unplugged the IPR valve and…

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Still waiting on the results of the oil analysis. As usual, USPS is taking forever to get the sample to the lab. As soon as I hear something I'll update everyone. Meantime I wanted to post the relative compression capture I have. As I mentioned, I'm going to try and get new captures with a sync when I go back out there. The biggest challenge with them is coordinating a time where the truck can…

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

I know this one has been open for way too long and for that I apologize, The customer has been using the truck and we've been trying to coordinate time to down it for further diagnosing. Since this post began, the truck has developed a hard start hot issue related to a leak in the high pressure oil system. I currently have the truck downed at his facility and awaiting some tooling to verify the…

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Zachary Mobile Technician
Austin, Texas
Zachary Resolution
 

Finally have a conclusion to this for anyone who may be interested. These captures were shown in another recent post I had, but are relevant to the conclusion of this one too. Further details of how I did this are in that post entitled "Cam & Crank Waveform Reference." The first capture shows relative compression with Cam & Crank Sensor Waveforms. The Escope unfortunately doesn't allow…

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Michael Diagnostician
Champaign, Illinois
Michael Default
 

Zachary glad you got the issue resolved. For the escope limited I don't know if the new software will work with it but just so you know the new software makes it very easy to move the channels up and down and we now have the crank misfire and relative compression test along with fast capture. If you are interested in upgrading let me know and we can talk more about it.

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Thanks Michael. When you say it's very easy to move channels up & down are you referring to the offsets? Or can you actually show them with different scales like appears to be possible on the Pico (don't have one, just going off the screen captures I've seen.) After I read your post I checked & the Limited has a software update as well. Funny you should mention upgrading, I was just…

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Michael Diagnostician
Champaign, Illinois
Michael Default
 

Just give me a email through my website mjediagnostics​.​com with your contact info and I'll give you a call asap.

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

That sounds great Michael. I'm sending you a message now and should be available throughout the week to chat. Thanks so much!

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