Yuck, I don't even want to think what mine looks like at 72k miles.

 

2017 2.8L Duramax
45,000 miles

Purchased used, 1 owner.

DPF failed at 44k miles, replaced under warranty.

GM offers a Diesel Induction Service that is supposed to clean this out for around $300. Plan to have this done before the warranty runs out at 60k miles.

Edited: Disregard, misread earlier

 

GM does not offer such a service. Nor is it recommended. So eitheir you heard wrong or were lied to.

 

You seem to be some sort of authority on the matter. If tunes, deletes, and catch cans aren't recommended/allowed under warranty, what is recommended then to clean out the intake?

 

Often times the dealer offers a service from BG or a similar company. BG products actually work quite well if you look into them, however I haven't used the diesel induction service before.

 

As a first time diesel owner, this thread is pretty interesting to me. Can we side-step the 'dealer recommended' or 'dealer offered' part of this discussion and get into whether the service is necessary for our diesels? If so, at what mileage? Who's got some good long term diesel or mechanic experience and can speak to this? Thanks!

 

Same boat. I have an appointment to have the induction service done in 2 weeks (47k miles). That leaves 13k miles left on the power train warranty, in case the service causes any faults in the DPF. After the warranty expires, I plan to run a delete/tune or trade it in if it becomes too much of a hassle.

Standing by if there is any better guidance by trained diesel mechanic/professional.

 

It is not hard to understand wanting to get rid of that nasty buildup. Our trucks run lot of EGR in order to meet stringent emissions requirements while not using massive quantities of DEF, and they pass a lot of oil mist as the valve cover's PCV bung looks like something from the 60's with no effort made to coalesce the oil mist out of the PCV stream. Lots of EGR + lots of oil mist = lots of goo, truly epic amounts of goo. The intake manifold has a MAP sensor by the EGR inlet valve that is buried in that stuff too.

The avoidance of this mess is why many of us advocate so vocally that these trucks need a catch can. At least if you take the oil out of the equation, you are left with mostly dry carbon. That is not awesome either, but a massive improvement in less bad.

So you have an intake full of goo - now what? Dissolving it with strong liquid chemicals and flushing that stuff into the engine in a dissolved black slurry from Hell is a monumentally bad idea. The only really safe way to deal with that is to have the intake system removed and walnut blasted, an expensive proposition. So what to do? Remove and clean the MAP sensor (to the left of the EGR valve) and add a catch can. The first thing do do when on finds themselves in a hole is to stop digging.

Customers should not have to add catch cans, tune their engines (thus voiding the powertrain warranty) or otherwise do backyard engineering to make their trucks perform and last for a decent period of time, and yet here we are. GM really should be ashamed of themselves.

People ask me how I like my truck and I tell them I love it, as I have taken a very active involvement in dialing it in by taking the warranty risk and tuning it to turn EGR off early in it's life, and I am anal about running fuel additive to improve lubricity in the hope of avoiding potential high pressure pump and injector failures. The 2.8 is a great power train as it is very efficient, has lots of torque and cool as Hell in general to have in a mid size truck, but I would never recommend this powertrain to a I just wanna get in it, turn the key and drive it buyer. We have the V6 and even the 2.5 four banger for that...

 

Thank you for taking the time to write. I appreciate your advise on not forcing the chemicals through the engine. I have the ADP catch can sitting in the garage now. Was waiting until warranty expires before installing, but sounds like I need to install sooner than later.

 

I cleaned mine myself using a shop vac to suck out the chunks white I scraped the edges with a plastic trim tool. The stuff is nasty and thick and I would not wanting it breaking loss and falling into the intake. I was a service advisor at a Chevy dealer for 7 years and can tell you that most techs just hooked up the cleaner and sprayer and let it run. None are going to do the work needed to clean it correctly and the chemicals used are not going to get this nasty stuff out.


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In the TDi world it is common to remove the ‘throttle body’ and intake manifold to clean them. Those folks would never just shoot that chemical into the air intake hoping things would be flushed out.
In port injected vehicles the intake can get gross and is also part of their regular maintenance.

 

On the TDI it actually would require that clean out around 40k miles or you would begin to notice the engine choking when attempting to get the air-fuel mixture past the throttle body and into the manifold and thus into the cylinders to do the work. Nasty clean out work. Afterwards pretty much convinced the owner to take on EGR stealth practices by modding the intake to remove the EGR portion or use a "race pipe" which also removed the engine shut down butterfly flap. Now if you can imagine having to remove all of that intake hardware off of a 2.8L engine to do a clean out at some point it is not hard to imagine why so many take pro-active measures to dis - arm these systems just so the engine has a chance to survive beyond that point of choking on the carbon-oil post combustion tar. Really sad to have to consider such actions but it is a inevitable reality on these engines too.

 

Soot in the EGR should normally be dry. This will coat the intake but otherwise be harmless. What I'm seeing in this thread and hearing described (about the VWs) is soot that is wet with hydrocarbons. I'm also less concerned with that in the intake manifold, but it could present problems around smaller areas like ports in the head.

So, do we know if this wet, sticky soot is a result of poor oil separation in the CCV circuit? Or is the engine running a very high volatile soot fraction in the exhaust itself due to either light load or late injection?

For that matter, does the 2.8 Duramax regenerate the DPF with late post injection, or does it have a fuel injector in the exhaust pipe downstream of the turbine?

 

We were hoping these were things that you would answer! Half kidding. 😉

 

I’m still early in the learning curve on modern Diesel engines and their emissions, and am on the fence regarding a catch can (though I like the idea in general). I bought a twin turbo Audi 20 years ago and there was considerable discussion on the benefits of adding a catch can to it. I never did and the engine ran strong, but that was a gasoline engine.

Edit, side note: I would pay considerably to be able to take a course offered by Chevrolet (not a dealership, but from the design and implementation engineering departments) that went into detail on the engine, transmission, electronics (ECM/BCM’s) and how everything incorporates. I want to be actively, cognitively engaged in the servicing of my truck.

 

Edit, side note: I would pay considerably to be able to take a course offered by Chevrolet (not a dealership, but from the design and implementation engineering departments) that went into detail on the engine, transmission, electronics (ECM/BCM’s) and how everything incorporates. I want to be actively, cognitively engaged in the servicing of my truck.

you can get the pdf version of the full dealer manual (all 14,000 or so pages of it...) on ebay.

the introduction section to each major system contains multiple page descriptions of the overall functionality of that system and how its various major components are interrelated.

if more folks had a copy of that it would go a long way to stopping some of the confusion on these forums about the basic function of the bits on these trucks
it also contains detailed troubleshooting steps for every fault code. well worth the $10-20 you'll pay...

 

A closed crankcase is a challenge in any turbocharged engine. You have to introduce the crankcase gases into the intake tract before the compressor wheel. Obviously later in the tract won't work because the pressure post-compressor is high. Flow would be backwards and you would pressurize the crankcase and blow out all the seals.

Anyway, the problem is that you don't really want oily, wet gases in your compressor or in your charge air cooler. You also do not ever want anything in a liquid or solid state entering the compressor wheel. What I've seen in all HD engines is that as the designs all moved to closed crankcase systems, rather fancy oil separators were added to all of the engines. Both Detroit and Volvo use something like this, which uses an oil driven impeller to power a spinner than separates out tiny oil droplets in a centrifuge.

I have not looked into the 2.8L valve cover to see what is in there for oil separation. There is clearly nothing between the valve cover and the inlet. I'll probably add an additional separator based on evidence I have seen here. The keys are to make sure the device does not increase crankcase pressure much nominally, and especially to make sure there is no chance for it to freeze up and block off the entire CCV. Some kind of relieve valve is strongly recommended.

 

I'll probably add an additional separator based on evidence I have seen here. The keys are to make sure the device does not increase crankcase pressure much nominally, and especially to make sure there is no chance for it to freeze up and block off the entire CCV. Some kind of relieve valve is strongly recommended.

Agree 100%. The Provent 200, Raccor and I am sure others have simple spring loaded flapper relief valves.

Another issue that can arise, especially in wet/cold environments, is the catch can element can freeze, as the catch can will coalesce water under those conditions, and then the water freezes. Without a relief valve, there goes the main seal. With a relief valve activated, you might have a small oily mess. I will take the oily mess

Then there are bent turbo fins, a not uncommon occurrence in cold climates. Small pieces of ice can form and fall into the fast spinning turbo wheel, bending the fins. Some will disagree, but I believe a catch can should help protect against this as well.

Edit - about the black oil - interesting about the injection timing, that may be. In any case, the oil used to turn black almost immediately when my truck was stock. Guided by oil analysis, I change the oil at 7.5K miles and it is dark brown at that point, still not black. You would never know just looking at it that the oil came out of a diesel and it did not come out of a gas engine.

 

This is why diesel guys delete everything. A 5.9 with no emissions or a 6.6 duramax would regularly see 500k mi. All of the emissions BS? Now it’s all over the map, but a lot don’t make it there. If it were me, I’d delete right away. Check out some duramax forums, the full size boards will hold a ton of info on this stuff.


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Back to the OP, immediately after the throttle valve in the intake is the EGR mixer. This is the most sooted looking item in your photos. The corrugated metal tube attached to the EGR mixer is the EGR cold pipe, it connects the EGR cooler / valve assembly to the intake. Can you take a look inside the EGR cold pipe? I'd be interested to know if that pipe contains the same thick, sticky soot as the mixer or if it appears more like a thin, smoother black coating.

This would give us some idea if the hydrocarbons are in the EGR, or in the intake air.

 

Back to the OP, immediately after the throttle valve in the intake is the EGR mixer. This is the most sooted looking item in your photos. The corrugated metal tube attached to the EGR mixer is the EGR cold pipe, it connects the EGR cooler / valve assembly to the intake. Can you take a look inside the EGR cold pipe? I'd be interested to know if that pipe contains the same thick, sticky soot as the mixer or if it appears more like a thin, smoother black coating.

This would give us some idea if the hydrocarbons are in the EGR, or in the intake air.

I have not got that far. My original question was to whether it would be good to have the BG Induction treatment done to clean all this out first, then move forward with catch can, deletes, etc. I think from all the feedback, conclusion is Induction treatment chemicals going through engine: bad, not worth the benefits of a clean intake.

I will move forward with manual cleaning of the pieces, and/or try to find someone who does walnut blasting near me.

 

@JeffreyG , the 2.8L uses a 5th injector , in exhaust steam to inject fuel for DPF clean out. Thankful it doesn't do it in cylinder like the LMM and 6.7L Cummins. LML and L5P use 9th injector in exhaust stream like the LWN .

 

My take from this is that there is no problem in the EGR circuit. The issue seems to be that the CCV is failing to separate the oil mist, mainly because it has no device to do so. Oil mist will foul the compressor wheel, CAC, and then mix with soot at the EGR mixer.

It's strange that light duty diesel engine designers tend to consider oil fouling as acceptable and they don't tend to include robust oil separation. When CCVs came to the heavy duty diesel engine market, robust oil separation was an absolute must as a design criteria.

 

It's strange that light duty diesel engine designers tend to consider oil fouling as acceptable and they don't tend to include robust oil separation. When CCVs came to the heavy duty diesel engine market, robust oil separation was an absolute must as a design criteria.

the target mileage, service intervals, and overall component cost are significantly lower, i dont think thats so surprising.

 

FWIW, my most recent oil change at 6 900 mi, 9% OLM, 5W40, I drained 6 oz out of the Provent, all oil. The previous 2 drainings yielded 1 and 3 ozs, respectively at similar mileage. This device is working for me!

 

Burger oil separator going on today.

 

BMS catch can installed today. Was not impressed by the "bracket" sent by American Diesel Power, but the hoses fit well once cut to size. 1x1/4 inch aluminum stock from Lowes for $8.

 

After only about 300 miles. Significant amount of condensed water with oily sludge at the bottom.

 

After only about 300 miles. Significant amount of condensed water with oily sludge at the bottom.

Eww. Kinda makes you glad you installed that eh?

 

Indeed. A good catch can should make the DPF's life a lot easier by preventing the intake of all that mist. I do believe more far more oil goes out the valve cover bung than past the rings, etc.

 

So just a spit ball here.. in the tuner car world it is common to put a catch can on. Most would agree that Cobb makes a nice setup with baffles and is designed to be plummed into the coolant system as well as drain back into the oil pan... the colant is an awesome idea in my perspective. Heats the unit keeps it from freezing and helps with condensed water vapor. Any reason we don't have this system available for our diesels?? Seems like a no brainer but I dont know how one would retrofit this to our needs ?

 

One of the benefits of a catch can on our 2.8 is to capture and condense the water vapor so the water doesn't freeze at the junction of the PCV system and the induction tube. Which in sub-freezing temps creates an ice chunk that can break off and go into the turbo, then bending turbo blades. We are better off, condensing the water in the can, and draining it there on occasion.

 

Raccor offers a heating kit for it's very nice CV4500 catch cans that some have used on their 2.8s. The only problem with that premium bad ass setup is it does cost quite a bit, the cans alone are around $250, I am guessing $400 for the whole deal with heating element.

https://www.parker.com/static_content/parkerimages/Racor/12994%20Rev%20-%20(CCV%20Heater%20Kits).pdf

 

exactly
i think the raccor and the larger mann setups (being that theyre designed for heavier equipment) are the only worthwhile options for a relatively maintenance free configuration that doesnt run the risk of blowing any seals in cold weather