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So, I have been wondering. With all the talk of oil catch cans to catch oil leaking back to the turbo, I mean, that is the reason for it, right or what it does? Or do I have something wrong? Anyways, I wondered if there wasn't a more simple fix than just adding a catch can.

I did some research last night on it, since I have been wondering if I have oil seeping into the turbo/ turbo inlet. One of the guys who used to work with me, he does a lot of work on diesel engines. He said that if you have a little oil in a Variable Vane Turbo (VVT) or a Variable Geometry Turbo (VGT: which is what our trucks have I believe), it's alright. He said that on say an LB7 Duramax, you do NOT want oil in the turbo like ours are showing as that would be bad. Those did not have VVT or VGT turbos, they had....well, neither. Just a standard turbo with a wastegate that can't be controlled electronically like our trucks have with turbo braking.

Is it really that bad for our trucks to have oil like they are showing in the turbo inlet/ mouth?


Also; not everyone is having this issue. There must be some reason. Again, I was researching last night and found an article on reasons that cause turbos to blow, leak, or burn oil. The whole list is at the bottom of this article for you guys to look at, but 2 of them caught my attention:

6. Hot Shut Offs.
After You Drive Your Turbocharged Vehicle Hard, You Should let the Engine idle for 1 to 2 Minutes to Allow The Oil to Circulate Through the Turbocharger to Remove the Heat from the Internal Parts of the Turbo. If You Do Not Do this, Then the Next Time You Start the Vehicle up, The Turbo Internals Could Be Dry, Which can Cause the Internal Parts the Wear Out Prematurely.
7. Improper Oil Weight. Just like Engines, Turbochargers have a Required Thickness of Oil to be Used. If you Use too Thin of oil Weight For the Ambient Temperatures, Your Turbo can Result in Blowing Oil. The Minimum Weight Required is 10w 30, But Often Some People Are Able to Run 5W Oil in Their Cars in Below 0 Degree Temperatures, but just Remember Your taking a Risk if You Forget to change the OIl When Warmer Temperatures Come Around, Your Turbo Will Fail Quickly!

I have always heard that you should let your truck cool down for a few minutes after running it, especially if it's hot out or if you just took a long drive or hauled something. It's good for the turbo. But I never really knew why. This explanation makes sense. So, are you guys bothering to let your truck idle for even 1-2 minutes after driving them, or are you just treating it like a gas engine/ non-turbo vehicle and shutting it off as soon as you get to your destination? Might be the cause of the oil leakage.

Also, the improper weight caught my attention as it mentions, you should run a heavier weight oil than GM is recommending when run in our trucks. Could be why the oil leaks by. Heck, you might go out and check the truck now and you'll find you have oil leaked by, but if you go out in the winter time, you might not find anything. That would give merit to this claim, for our trucks at least.

So, what do you guys think? Also, here is the full list of reasons like I mentioned.



The Most Common Response People say is Turbo Seals are Bad, But Im Going to Teach You in This Post That Often this is the most Uneducated Answer. Here is a list of Most Common Problems to Least Common in Order. In This List a Lot of the Time The Turbo Can Still Be “Good” But Blowing Oil.

The Top Reasons Why a Turbo Blows OIl:

  1. The Oil Drain Size Is Too Small. Most Aftermarket Drain Fittings Have too Small of an Inside Diameter Which is Often the Problem. A Factory MHI Drain is 16mm Inside Diameter. Aftermarket -10 an Drain Fittings are 12mm Inside Diameter. This Causes the Oil to not Drain Effieciently and the OIl backs up in the cartridge. With new oil filling the Cartridge and the Old oil not being removed, the oil pressure builds up in the cartridge and is forced out the seals.
  2. Blocking Crank Case Ventilation Causes the Pressure in the oil Pan to Build up, Which no Longer Allows the Oil to Drain From the Turbo Properly, Because the Crank Case is Pressurized.
  3. Oil Level. The OIl Level Can Be Higher Than the Oil Seals, if You Put too Much Oil in the Oil Pan, or If the Turbocharger is Sitting to Low in Relation to the OIl Level. Both Situations can Cause oil to Lean Past the Seals.
  4. Oil Pressure. The Oil Pressure Being Too Low, will Cause The Turbo To Wear the Internal Parts of the Turbo. Usually Once the turbo develops some In and Out Shaft play the Seals get Worn out in the Process, Which makes the Turbo Need a Rebuild. The Oil Pressure Being Too High, is Never the a Problem Unless The Oil Drain is Not Large Enough To Remove the Volume That is Being Fed into The Turbocharger. Ball Bearing Turbos Need a .035” Restrictor However, Because their Cartridges Are Much Smaller, and They Can only Hold So Much Volume.
  5. Oil Restrictor in a Journal Bearing Turbo. Having and Oil Restrictor in a Journal Bearing Turbo can Causes Turbos to Eventually to Blow oil, Because it Starves the Turbo Of Oil, Which Causes the Internals of the Turbo to Wear out (including the Seals). Don’t Use a Restrictor with a Journal Bearing Turbo, if You think the OIl pressure is “Too High” Then a Drain with a Larger Inside Diameter.
  6. Hot Shut Offs. After You Drive Your Turbocharged Vehicle Hard, You Should let the Engine idle for 1 to 2 Minutes to Allow The Oil to Circulate Through the Turbocharger to Remove the Heat from the Internal Parts of the Turbo. If You Do Not Do this, Then the Next Time You Start the Vehicle up, The Turbo Internals Could Be Dry, Which can Cause the Internal Parts the Wear Out Prematurely.
  7. Improper Oil Weight. Just like Engines, Turbochargers have a Required Thickness of Oil to be Used. If you Use too Thin of oil Weight For the Ambient Temperatures, Your Turbo can Result in Blowing Oil. The Minimum Weight Required is 10w 30, But Often Some People Are Able to Run 5W Oil in Their Cars in Below 0 Degree Temperatures, but just Remember Your taking a Risk if You Forget to change the OIl When Warmer Temperatures Come Around, Your Turbo Will Fail Quickly!
  8. Oil Contamination Oil Contamination Will Destroy a Turbo Quickly. The Foreign Material, can be Debris from a Previous Blown Engine, sand blast media, leftover rtv gasket maker, or Anything that Could have Fallen into the Oil Pan. This Is the Worst Case to Have, Because it Often requires the Engine to Be Rebuilt and Flushed Thoroughly. These Particles can Be Trapped in the OIl Journals, Which Never Allows The Debris to Leave No Matter How Much You Change the Engine Oil. Often If these Particles Make it to the Turbocharger, the Bearing Housing Gets Scared and Causes the Cartridge to often Need Replacing. Luckily Now We offer New Cartridges for Turbochargers!
 

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Catch can is to condense and catch the oil vapors out of the pcv breather hose, which tends to dump oil into the intake hose in front of the turbo. Pull your intake hose or your pcv hose, it's prolly full of oil residue.

The posts/info you mentioned are dealing with turbos that leak oil. Having a turbo that leaks oil is a completely different problem, one which a catch can won't fix.

Our turbos have a dedicated oil delivery system for fast oil delivery and Our turbos are water cooled as well, and no I don't let it cool off after I drive it.

"
  • Oiling circuit that includes
    a dedicated feed for the turbocharger to provide increased pressure at the turbo and faster oil delivery
  • New Watercooled Turbo (2.8L) - The improved variable-geometry turbo incorporates a water-cooling system in the turbine housing to reduce heat when operating at high speeds and full load. This feature extends the life of the turbo and the engine"
I'm not pimping the catch can, still dunno how well it works. I know my catch can isn't completely efficient (still get oily residue in my intake), I got about a teaspoon of oil out of it after 2000 miles. That's a teaspoon less oil in my intercooler. I've seen turbo vw bugs with a quart of oil in the intercooler (they have a drain plug on the intercooler, if that's an indication)

Somebody else who knows more will chime in and clarify the rest

Too much stuff to worry about on these trucks. Half the time I wish I still had my old 5.3 gas truck, the other time I just drive this truck like I stole it and don't worry about it. Lol
 

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Sorry, I edited that post like a hundred times.

Pcv breather getting gunk into the intake is no new thing. Its very similar to the egr valve getting gunk into the throttle body. It's well documented that this is common across many makes and models

The EPA does not want any petroleum based products getting into the environment, that is why your PCV breather has to be vented into the intake so those vapors are sucked in. Heck, in many areas, Atlanta is one of them, gas stations have to have stage 2 vapor recovery system which has a coaxial gas hose and As you fill your car with gas, the vapor that occupied the space in your gas tank is sucked out into an underground tank and stored for pickup.
 

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Discussion Starter #5
That's interesting. I didn't know that about the turbo's being water-cooled so that you don't have worry really about hot shutdowns. Good to know since they wife never has enough patience to sit around for a minute or two and cool the turbo off. There is a lot to worry about. Although, like I have stated a handful of times, I think removing the emissions system will clarify many of the problems we could/ do encounter.

I don't remember ever worrying about getting the oil vapor condensation in my LLY Duramax. I know it had the whole PCV thing, because there were a handful that did the reroute on that. But I had a VVT turbo. I don't believe it was water-cooled. I remember on 2 separate occasions when I had to take off the turbo inlet and exposed the inlet to the turbo and turbine wheel and neither time did I notice any oil there.

That truck had 160,000 miles on it when I got it and 180,000 when I sold it. I did try and let it cool down most of the time, for a few minutes. Also, in that truck I ran a heavier oil. Don't know what the previous owner ran, but I used 5w40 Rotella T6. That article I shared made it sound like all turbos are capable of letting oil go by, especially if the PCV is rerouted in front of the turbo/ intake. Don't know if oil condensation is a big thing on those other Duramax engines, if I got lucky, or was doing something right.
 

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That's interesting. I didn't know that about the turbo's being water-cooled so that you don't have worry really about hot shutdowns. Good to know since they wife never has enough patience to sit around for a minute or two and cool the turbo off. There is a lot to worry about. Although, like I have stated a handful of times, I think removing the emissions system will clarify many of the problems we could/ do encounter.

I don't remember ever worrying about getting the oil vapor condensation in my LLY Duramax. I know it had the whole PCV thing, because there were a handful that did the reroute on that. But I had a VVT turbo. I don't believe it was water-cooled. I remember on 2 separate occasions when I had to take off the turbo inlet and exposed the inlet to the turbo and turbine wheel and neither time did I notice any oil there.

That truck had 160,000 miles on it when I got it and 180,000 when I sold it. I did try and let it cool down most of the time, for a few minutes. Also, in that truck I ran a heavier oil. Don't know what the previous owner ran, but I used 5w40 Rotella T6. That article I shared made it sound like all turbos are capable of letting oil go by, especially if the PCV is rerouted in front of the turbo/ intake. Don't know if oil condensation is a big thing on those other Duramax engines, if I got lucky, or was doing something right.
Most if not all modern VVT or VGT turbos are all water cooled these days. Letting the oil in the turbo circulate for a minute or two is still a good idea if you just ran it hard prior to coming to a stop w/ engine shutdown. Otherwise it's not necessary with normal driving.

The only oil entering the turbo should be vapor from the PCV system. Anything else would be from blown seals in the turbo or something upstream. This is dangerous and can lead to a runaway in any diesel vehicle.

Oil condensation is called volatility or NOACK %. The quality of the base stocks of the oil determine it's volatility and is measured as NOACK % weight loss (g/100g) (ASTM D5800) .

The old CJ-4 Rotella T-6 used to have high volatility, it was measured by PQI and I thinks it was almost 13%. As far as I know, the new CK-4 T6 has not been measured yet.

For example, numbers pulled from memory.

A typical "good" NOACK rating for most synthetics is around 10%.
Redline and other premium oils made from Group V Esters are around 6%.
Penzoil Platinum Euro L has an excellent volatility rating and has been measured around 6%. EDITED - PP Euro has been re-formulated and now has average NOACK.
Mobile 1 ESP also has an excellent volatility rating @ around 6%.
Amsoil makes some synthetics that are sub 5% .

So basically the lower the NOACK % the least oil consumption and vapor is generated as the oil boils off. If you don't want to install a catch can to catch the vapor, you can try using an oil with a low NOACK as less vapor will be created.
 

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Discussion Starter #7
Most if not all modern VVT or VGT turbos are all water cooled these days. Letting the oil in the turbo circulate for a minute or two is still a good idea if you just ran it hard prior to coming to a stop w/ engine shutdown. Otherwise it's not necessary with normal driving.

The only oil entering the turbo should be vapor from the PCV system. Anything else would be from blown seals in the turbo or something upstream. This is dangerous and can lead to a runaway in any diesel vehicle.

Oil condensation is called volatility or NOACK %. The quality of the base stocks of the oil determine it's volatility and is measured as NOACK % weight loss (g/100g) (ASTM D5800) .

The old CJ-4 Rotella T-6 used to have high volatility, it was measured by PQI and I thinks it was almost 13%. As far as I know, the new CK-4 T6 has not been measured yet.

For example, numbers pulled from memory.

A typical "good" NOACK rating for most synthetics is around 10%.
Redline and other premium oils made from Group V Esters are around 6%.
Penzoil Platinum Euro L has an excellent volatility rating and has been measured around 6%.
Mobile 1 ESP also has an excellent volatility rating @ around 6%.
Amsoil makes some synthetics that are sub 5% .

So basically the lower the NOACK % the least oil consumption and vapor is generated as the oil boils off. If you don't want to install a catch can to catch the vapor, you can try using an oil with a low NOACK as less vapor will be created.
Thanks for that, that's really good to know. I mean, some of that doesn't make sense but that last part and the first are what I took away.

Question though: did you used to or do you work for an oil company or make oils? Because you know a lot about them :)
 

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No I don't work for an oil company. I just know a few things about modern diesels and oil chemistry.

I remember maybe 6-7 years ago, the mechanic who works on my TDI told me that most mobil 1 oils aren't actually synthetic anymore. Just the Delvac ESP and 0w40 European formula were still true synthetics. All the other M1 oils were made from a higher grade of refined petroleum and Mobil had won a lawsuit regarding labeling and how they could define a "synthetic" oil. I was shocked as I had been buying Mobil 1 for as long a I could remember, and also deceived as a consumer because I wasn't buying what I thought. It was a cheapened product, "value engineered" to compete with the other oils on the walmart shelves.

So I found this forum https://bobistheoilguy.com/forums/ubbthreads.php/forum_summary and started reading. If you want to learn how to read an oil data sheet this is a good place to find out how.
 

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Catch can is to condense and catch the oil vapors out of the pcv breather hose, which tends to dump oil into the intake hose in front of the turbo. Pull your intake hose or your pcv hose, it's prolly full of oil residue.

The posts/info you mentioned are dealing with turbos that leak oil. Having a turbo that leaks oil is a completely different problem, one which a catch can won't fix.

Our turbos have a dedicated oil delivery system for fast oil delivery and Our turbos are water cooled as well, and no I don't let it cool off after I drive it.

"
  • Oiling circuit that includes
    a dedicated feed for the turbocharger to provide increased pressure at the turbo and faster oil delivery
  • New Watercooled Turbo (2.8L) - The improved variable-geometry turbo incorporates a water-cooling system in the turbine housing to reduce heat when operating at high speeds and full load. This feature extends the life of the turbo and the engine"
I'm not pimping the catch can, still dunno how well it works. I know my catch can isn't completely efficient (still get oily residue in my intake), I got about a teaspoon of oil out of it after 2000 miles. That's a teaspoon less oil in my intercooler. I've seen turbo vw bugs with a quart of oil in the intercooler (they have a drain plug on the intercooler, if that's an indication)

Somebody else who knows more will chime in and clarify the rest

Too much stuff to worry about on these trucks. Half the time I wish I still had my old 5.3 gas truck, the other time I just drive this truck like I stole it and don't worry about it. Lol
G`day Rockcrawlerdude ,
Emptied my catch can at 10,000 km ( 6,000 miles ) and retrieved 75mls of oil. That`s a good result , 75mls that can`t go through my intercooler , turbo and inlet manifold.
Cheers,
Jontee
 

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I wonder if a different oil like AMSOIL would make a difference? I know they make an oil for our trucks, I’ve ran their oil in motorcycles and ATVs before. They seemed like they held up very well and on my motorcycles zx6r and 14 it seemed to boost mileage slightly. Has anyone tried it?
 

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I wonder if a different oil like AMSOIL would make a difference? I know they make an oil for our trucks, I’ve ran their oil in motorcycles and ATVs before. They seemed like they held up very well and on my motorcycles zx6r and 14 it seemed to boost mileage slightly. Has anyone tried it?
Haven’t tried that stuff but the voc on the Pennzoil Platinum euro L that i have been running is pretty low
 

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I use to run it in my built ktm450 rfs engine in a Atv frame.... had a lot of custom parts, 540kit ported etc everything but the crank was changed or modified . Anyways I could get 3 times the passes down the drag track with it then I could Lucas Oil or Dino oil before I started having issues shifting(sticking). I might give AMSOIL a try but I still have one free change left and my truck doesn’t get drove much.
 

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I wonder if a different oil like AMSOIL would make a difference? I know they make an oil for our trucks, I’ve ran their oil in motorcycles and ATVs before. They seemed like they held up very well and on my motorcycles zx6r and 14 it seemed to boost mileage slightly. Has anyone tried it?
Most formulators don't publish their oils volatility, in this case the only way to find the NOACK % is through independent testing. Only premium pure PAO and Ester based blended multigrade synthetics will have a low volatility.

Yes the Amsoil AEL 5w30 and does have low volatility for a Dexos 2 style oil.


The lowest NOACK % Dexos 2 leaders:

Mobil 1 ESP 5w30 = 5.6 %
Redline Euro 5w30 and 5w40 = 6 %
Amsoil AEL 5w30 = 7.1 %
 

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Yes, specifically the Mobil 1 ESP formula 5w30 variety was measured at 5.6% by an independent lab. And that number is dependent on their methodology and overall testing accuracy.

There are also other options in the synthetic 10w30 and 15w40 viscosity which have even lower volatility, tested range of 4-5% NOACK. These however are not Dexos 2 approved viscosities.
 

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Do we need a catch can?
Mega search on this topic says Big Time Yes.
Are there issues ...... yes

I been thinking about this big time so today I decided to do some investigating under the hood...
And it’s not good..

Here is what I did and found.
My truck is an 18 with 6k
Both the inlet and outlet of the inter cooler have oil leaking out of them.

I pulled the PCV hose off the turbo inlet. Then started the truck. The amount of oil vapour was amazing to say the least... you could see the haze of oil vapour coming out of the hose like a small smoke stack.
Inside the hose to the turbo was flooded with oil.
Now consider this...... as the turbo spools up it puts a considerable vacuum on the PVC hose.
This keeps the crank case of the motor under a vacuum. And it pulls as much vapour as possible doing so.
So
Does anyone know for sure if that unit on the turbo end of the PCV hose is a heater or could it be a vacuum sensor. A heater makes a lot of sense considering the amount of condensation in cold climates that comes from the PCV.... if that hose freezes there will be seal or gasket damage do to high pressures in the crank case. So be a where if you already have a catch can........
If it’s a heater that’s good.
I am thinking the best thing to do is block the turbo end of the hose off and connect the motor end to a filter and leave the hose vented to atmosphere. There is way to much oil getting into the turbo. And this oil is getting back into the intake and mixing with EGR exhaust soot that will clog up the intake and the valves.

Another concern is that maybe this oil is lubricating the turbo and also making up for the loss in lubricity in low sulfer diesel.
Because of the lower lubricity of low sulfer diesel, I add a small amount of 2 stroke oil to my Kabota tractor..
Is GM letting this vapour into the intake to make up for the fact we use low sulfer diesel and a non heavy duty diesel oil?

Would it be better to find a way to block off the EGR instead? That way the oil wouldn’t mix with the soot and mess up the intake.....

Even without the oil the soot from the EGR will eventually carbon up the intake.

We need a way to stop the oil, and is easily put back to stock in case warranty work is need.
 

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I feel that oil in the turbo is a bad thing. Over time the build up of oil on the veins of the impeller and variable boost inlet will decrease performance. If you plan on keeping your truck for a long time I would install a catch can. I bought the Holden Colorado catch can kit on E-Bay which came with the Provent a nice mounting bracket and lots of extra hose, clamps, and fittings. I also chose not to fight with getting the factory clamps off each end of the pcv line so I cut the tube in the center and plumbed in the Provent. Should the catch can need to be removed from the engine than only a coupling would be needed to join the factory pcv line back together.

I can't imagine with all the emphasis on emissions that GM would think oil vapors are a good way to lubricate the combustion chamber. In the same respect I don't understand why they would allow so much oil vapor to enter the intake system in the first place. I've cleaned intake plenums on non-turbo gas engines and the oil vapor build up in them can be quite substantial. It takes time to form but eventually an intake can become contaminated with burnt sludge.

I'm 56 yrs old and have owned practically every make of automobile out there. The one thing I have found is that they're all great when they run right and they suck when they don't.

Personally I really like my truck. It's probably for me the best vehicle I've ever owned and I want it to last me so I've chosen to take the proactive route and do the necessary measures to try and make it last a good long time. Preventive maintenance is the key to anything mechanical and the more knowledge you gain about this platform the more proactive you can be.

This forum is a great place to get helpful information.
Good luck with your truck and I hope provides you with many years of enjoyment.
 

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I feel that oil in the turbo is a bad thing. Over time the build up of oil on the veins of the impeller and variable boost inlet will decrease performance. If you plan on keeping your truck for a long time I would install a catch can. I bought the Holden Colorado catch can kit on E-Bay which came with the Provent a nice mounting bracket and lots of extra hose, clamps, and fittings. I also chose not to fight with getting the factory clamps off each end of the pcv line so I cut the tube in the center and plumbed in the Provent. Should the catch can need to be removed from the engine than only a coupling would be needed to join the factory pcv line back together.

I can't imagine with all the emphasis on emissions that GM would think oil vapors are a good way to lubricate the combustion chamber. In the same respect I don't understand why they would allow so much oil vapor to enter the intake system in the first place. I've cleaned intake plenums on non-turbo gas engines and the oil vapor build up in them can be quite substantial. It takes time to form but eventually an intake can become contaminated with burnt sludge.

I'm 56 yrs old and have owned practically every make of automobile out there. The one thing I have found is that they're all great when they run right and they suck when they don't.

Personally I really like my truck. It's probably for me the best vehicle I've ever owned and I want it to last me so I've chosen to take the proactive route and do the necessary measures to try and make it last a good long time. Preventive maintenance is the key to anything mechanical and the more knowledge you gain about this platform the more proactive you can be.

This forum is a great place to get helpful information.
Good luck with your truck and I hope provides you with many years of enjoyment.
I agree with you.
I just put the oil being feed into the turbo to try and get people to think.

Also I found a video on YouTube and the guy had some good ideas.
He also mentions that when a turbo is spun up even a small oil droplet or water carried from the PCV hitting the turbo blades will do damage.

Check out this video. Notice how he has an oil catch can that has trapped oil from just 1 week of use. Also take note that he has the hose disconnected from to output side of the catch can and there is still a lot of vapour.
So what he did was plumb the output of the catch can to his air filter box. The vapour that the catch can missed has to go through some foam filter that soaks up the oil like a sponge....
This was a good idea BUT it set a engine code.
The code was set because there is a sensor on the PVC hose that detects vacuum. The exact same setup as our DMax motors have.

Not unusual as both the baby Max and Rams eco diesel were designed by VM Motori

 

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Has anyone looked in to converting to open crankcase, and venting to ambient? Are there any sensors that would know this was happening?
 
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