Mystery Oil Leak

[Gary_1500HD]

Question for jz57, the o-ring that you replaced, do you recall the size or dash number? Great pic's, it tells me the black o-ring most likely is buna-n, if it was red/rust, I would be thinking silicone.

 

[ddann19]

i just noticed one in mine today also. Coming down from above the filter but can’t tell where from.

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You were right, oil cooler line leak. thanks.

 

[jz57]

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There is NO exact perfect matched size O-ring for this repairing. I bought a pack of assorted rubber O-ring, and picked up a roughly matched one.

Actually white Teflon pipe thread sealant can do same job.

Question for jz57, the o-ring that you replaced, do you recall the size or dash number? Great pic's, it tells me the black o-ring most likely is buna-n, if it was red/rust, I would be thinking silicone.

 

[gooffeyguy]

You just want to make sure to not get any of the teflon sealant in the areas where it can come off the threads and get into the oil/passages

Sent from my SM-G930V using Tapatalk

 

[wsteele]

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There is NO exact perfect matched size O-ring for this repairing. I bought a pack of assorted rubber O-ring, and picked up a roughly matched one.

Actually white Teflon pipe thread sealant can do same job.

That really doesn’t look like the proper use for an O-Ring. O-Rings are internal seals. For a flat flange surface, you would be much better off with something like a Statoseal.

 

[Koop]

Hmmm going to check for the o ring. Is that on the passenger side? I replaced the block off plate and gasket above the filter which eliminated the leak on the driver side but now I am getting this mysterious leak on the passenger side. I have a 07 yukon denali xl and usually you can slide under and visually inspect, but this time I can pin point exactly the sourcing. I have read everything from the oil sensor to now possibly oil cooler lines. Is there anywhere else that could possibly be allowing this? I am getting now to the point of little more than a quarter size dripping.

 

[Geotrash]

Hmmm going to check for the o ring. Is that on the passenger side? I replaced the block off plate and gasket above the filter which eliminated the leak on the driver side but now I am getting this mysterious leak on the passenger side. I have a 07 yukon denali xl and usually you can slide under and visually inspect, but this time I can pin point exactly the sourcing. I have read everything from the oil sensor to now possibly oil cooler lines. Is there anywhere else that could possibly be allowing this? I am getting now to the point of little more than a quarter size dripping.

Yes, the valve cover gasket on the passenger side is possible, and the rear main seal is also a possibility for that location.

 

[Koop]

Yes, the valve cover gasket on the passenger side is possible, and the rear main seal is also a possibility for that location.

Appreciate the feedback. I did the rear main seal 'hand/visual' check and that was bone dry after replacing the block-off plate on the driver side but as I have read here there is no '
true' way to gauge this unless I snake a camera up in there. Is this the driver-side valve gasket you're referring to? I like to get a visual approach first.

 

[wsteele]

Hmmm going to check for the o ring. Is that on the passenger side? I replaced the block off plate and gasket above the filter which eliminated the leak on the driver side but now I am getting this mysterious leak on the passenger side. I have a 07 yukon denali xl and usually you can slide under and visually inspect, but this time I can pin point exactly the sourcing. I have read everything from the oil sensor to now possibly oil cooler lines. Is there anywhere else that could possibly be allowing this? I am getting now to the point of little more than a quarter size dripping.

Is the source above the oil pan gasket line (i.e. is it leaking down from above that line)?

 

[Koop]

Is the source above the oil pan gasket line (i.e. is it leaking down from above that line)?

My last check was passenger side and seems to be slightly above/around the starter. I thought it was the oil plug...no. I saw a few drops come down when I wiped things clean then started the truck to try to take a look. Geotrash noted the valve gasket but I 'think'...again my opinion... I would smell or see smoke cause that engine gets hot. Again I could be wrong. I literally just came in from outside and its strictly on the passenger side (drips). So I am trying to see what is all on that side that could need a gasket replacement or complete replacement (hoses..etc.). Swear its like I solved one mystery (oil pressure), then another (driver side oil leak), and now this but this just feels like something simple yet complex cause I'm trying to lock in on the source.