LMM: Oil leak..help a dummy out

Osubeaver

Professional Grade
Aug 30, 2008
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I have an oil leak that presents itself on the bottom of the bellhousing and wondering if you all could help me out. The actual leak is much farther up the engine from what I can see. There are two areas with oil:

#1 - on the drivers side near the stock turbo has the most oil... can't tell exactly where it's coming from, although the oil is collected under the area in the yellow circle

470257511_B5Azi-L.jpg


#2 is on the passenger side - I've wiped away the oil (sorry) but it's near where the tube with the 2 screws mounts..... circled. Way less oil than the drivers side (just wet and gritty with dirt...no drops)

470257509_5TULU-L.jpg


#3 is where the oil appears to be running down the engine.

470257514_YBJXp-L.jpg


If I drive normally, I never see a drop on the ground. If I hammer on it for a while, I'll get enough to drip on the ground (a few drops not a puddle). I don't lose enough oil to notice it on the dipstick ever. The oil collects where the tranny and engine mate.

BTW this happened before the twins went on too, it just seems like there is more oil now....no quantitative data for that though so may be BS.

Thanks for any help.
 
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Alligator

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Nov 9, 2006
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Both area's circled are the PCV (positive crankcase ventilation) tube. The first pic is the entrance to the turbo inlet and the 2nd photo is where it attaches to the valve cover. You should do a re-route on this to negate any oil from being vented into the turbo inlet.
 

Alligator

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Nov 9, 2006
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Tony Burkhart has a kit that replaces it for ~ $75 or something or you can just cut that tube on either side, plug the hole in the inlet and get some 7/8 (i believe that's the size) fuel or heater hose and route them off to the side of the block or to a catch can.
 

Osubeaver

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Aug 30, 2008
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Wow, really.....

I guess I missed where there could be enough oil to go on the ground. I thought for some reason it was just oil in the turbo, pipes, etc.

thanks
 

Alligator

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Hey, I am no expert on that, but all areas circled are the PCV, and when ran there is a buildup of oil residue in those pipes. I can't tell from your comment if you are being smart or not though...

Do you have any blow by coming from the oil cap? Might be a bigger problem brewing or it could be nothing more than bad seals at either side of the PCV tube and the clamp not being on properly over the turbo inlet.
 

Osubeaver

Professional Grade
Aug 30, 2008
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Hey, I am no expert on that, but all areas circled are the PCV, and when ran there is a buildup of oil residue in those pipes. I can't tell from your comment if you are being smart or not though...

Do you have any blow by coming from the oil cap? Might be a bigger problem brewing or it could be nothing more than bad seals at either side of the PCV tube and the clamp not being on properly over the turbo inlet.

Not being smart at all.

Nothing on the oil cap. I'll look closer at the seal area, the clamp to the turbo inlet looks good from what I can see.
 

sweetdiesel

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Aug 6, 2006
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Have you had the stock turbo off? If so could be leaking from the cam journal or oil return

X2 on the pcv rerought:D
 

JoshH

Daggum farm truck
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PCV should have been rerouted with the twin install.
 

Alligator

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Not being smart at all.

Nothing on the oil cap. I'll look closer at the seal area, the clamp to the turbo inlet looks good from what I can see.

Ok, the internet can make a simple comment sound funny...:hug:

Try taking the oil cap off and see if you have any blow by coming out of the fill tube.
 

ripmf666

Active member
Sep 20, 2006
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Check the oil supply line on top of the turbo going to the twin could of came loose and leaking down the side of the block.
 

sweetdiesel

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Aug 6, 2006
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Check the oil supply line on top of the turbo going to the twin could of came loose and leaking down the side of the block.

Exactly the pic youve shown has 3 spots the oil could come from besides the PCV If the stock turbo was never removed its probably what henry said with the turbo oil inlet since that was changed with the twin install:)
 

slowlmm

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Mar 2, 2008
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Do what chad said and reroute your pcv. its a comon problem on LMMs Gm even knows of it and there fix is to seal the intake with silicone and remount the dwon pipe. YOur truck will be much happier after the reroute> good luck
 

duratothemax

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Aug 28, 2006
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holy crap you've been pressurizing the crank case with 50psi from the twins??!? :eek:

Im surprised you havent blown out the front or rear main seal.
 
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slowlmm

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Mar 2, 2008
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holy crap you've been pressurizing the crank case with 50psi from the twins??!? :eek:

Im surprised you havent blown out the front or rear main seal.

How would he be presurizing the crank case? there is check valves in the valve covers. Im pretty sure oil would only come out not put presure in. but i could be wrong.
 

Osubeaver

Professional Grade
Aug 30, 2008
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holy crap you've been pressurizing the crank case with 50psi from the twins??!? :eek:

Im surprised you havent blown out the front or rear main seal.

The 90 deg fitting on the PCV tube isn't connected to anything. I didn't do the install so I'm not sure how that got messed up with no reroute done. Nathan said there should have been fittings to do it in the kit.

Am I correct in saying that the way it is right now, my PCV is "rerouted" right on top the motor?

Thanks for all the help everybody.