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oily blowby?


Donald  smith

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around 500 I beleive ! 450 is a little low But! Turbo can cause this ! Exhaust goes by the shaft seals under high boost!we built a tool to cap both ends the inlet air and exhaust side and aplly  40 psi shop air to it, to find this very issue Haven't seen it happen for quite some time

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28 minutes ago, Donald smith said:

the turbo was replaced  because it was leaking oil in     ex.  pipe   i think     but still   oil comes out road draft tube  

dosent mean the turbo aint faulty! while  running at idle does it have alot of bloby with the the oil filler lid off?

Edited by fjh
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Turbo is possible, operable compression is 350-500 PSI.  Just curious.... Is the breather filter clogged and then "Puking" oil when pressure builds? If you pull the dipstick while running, is it blowing oil out, or excessive pressure? How about the air compressor?  

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I have to think about this for a bit.... You have good compression on all 6, the oil level is not rising, it does it when working it hard, the compressor is new, the turbo is new,   Yep. I need to think on it.. jojo

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I have been pondering about this as well. If the turbo and compressor is new, no loss of engine power is noticed then one would think that it is not the engine at fault. Has the engine oil dip stick been replaced? The oil level should be 32L or 8.5 gallons. What kind of vocation is this vehicle? There was a service bulletin that corrected this issue. If this vehicle is a cement mixer or a vehicle that is managing steep grades then it is possible that the engine oil can spill out the crankcase breather. Mack has a service bulletin that relocated the breather for these applications.

Take a read and see if this fits your vehicle.

V

sb214024.pdf

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this   truck is a  roll  off  cv model      i believe   dip stick is original   i  did  leak down tests  of  cylinders    all   hold    100   psi   for  about 20  seconds

  or  so  then  drop off       it  doesnt  blue smoke      i   was  thinking    there are  plugs  behind    cam gear     maybe  one  is  loose  ? 

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There is a fuel gallery plug behind the timing cover, I believe it's a 1/4". I was thinking it may be this. The cam gear may whip the fuel and oil out the breather. It's worth a check. Once you remove the timing cover, apply the fuel primer and see if it leaks out. The plug is probably lòose. Remove the plug and reseal it with teflon tape. I think all ideas have been exhausted. Let us know what you decide to do.

V

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1 hour ago, Vmac3 said:

There is a fuel gallery plug behind the timing cover, I believe it's a 1/4". I was thinking it may be this. The cam gear may whip the fuel and oil out the breather. It's worth a check. Once you remove the timing cover, apply the fuel primer and see if it leaks out. The plug is probably lòose. Remove the plug and reseal it with teflon tape. I think all ideas have been exhausted. Let us know what you decide to do.

V

My opinion!

We"ve Been told ! The fuel level is staying consistent? oil sample ? I have seen the turbos bad from the get go! Chase The facts Don't throw anymore  parts till ya got some facts get an oil sample! If ya got the where with all Build some caps for the turbo  and pressure it up with shop air ! two peices of flat 3/8 plate two pieces of 3/8 ready rod and some old mudflap and   You can make the tool in under an hour! with this you can check Everything you need ! even Valve guides! remove the drain tube from the turbo put 40  regulated shop air psi to it This will test EVERY nook and cranny on the unit for leaks you may also have to cap the compressor outlet on the thing if its plumbed direct to the compressor! 

 

Just sayin!

Edited by fjh
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So true "F".. I've done something similar, had the valve covers off, barred the engine over (with a helper) and watched for air leaks and bubbles in the oil around the valves.. yes, stop throwing parts at it and keep testing..  jojo

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In the case of these new emission units  sometimes you have no choice Nox sensors is an example Cheap Shit ! Hit and miss ! If eveything up stream checks out then Throw the TAIWAN   part At it No Choice! We have  some guys here at my shop  that have good senses ! ME NOT included in this Group !

But have seen what they do And when they do it Most of This shit is just Magic To me! DON"T like working on it!Hurts My Brain! 🙄

Edited by fjh
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Just curious, "F"???   When they fix it, do they know how and why? Because when I was in the Dealership, I saw that.. Even as A customer, I could'nt get a good explanation on how it was fixed. Of course the MIL light would come back on a short time later..

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Usually I here the resolution ! Like I said they usually work thru the possible up steam causes first the DAM  programing up grades/   egr flow fuel  doser crap /def doser issues Crystal build up ect, often  caused by  cracked ash cans and air leaks within that sector To rule out the obvious and , Then Canon the nox sensors, only way to be sure,  AND MACK DON"T TELL YOU F all How you've fix it if the last thing you do is parts canon! If it fixes it you can attribute it to overpriced  Dollar store Parts!  Really ,No different than what we've been talking about with this possible  blow by ,oil slobber issue,! 

fred

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