Oil leak rear main seal maybe????

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mrs111180

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So I have a pretty good oil leak I have taken off the view cover and it looks dry any suggestions 07 yukon denali 6.2l AWD1000007785.jpg1000007784.jpg1000007790.jpg1000007789.jpg1000007786.jpgestions?
 

strutaeng

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Very likely, yes.

Check the top of the engine on the rear to make sure it's not running down there. Valley cover, camshaft position sensor (has an O-ring down there) and oil pressure sender. Those can all be potential leak sources.

Add dye to the oil and checking with a UV light is also a good way to pinpoint leaks.
 

j91z28d1

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if it's not the rear main, it's the oil pan, depending on mileage but also the age, it always seems to be a oil pain. mine just started myself. annoying.


it could be the oil block off plate above the oil filter. be careful tightening the bolts, they strip eazy. could replace that gasket, or there's a billet plate with a o ring for cheap to try.
 
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mrs111180

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You must be in California or someplace else warm - that thing is clean! +1 on checking the oil cooler block-off plate above the oil filter. Common leak spot.
Im actually from the New England area but currently in KS just cleaned the heck out of it for better view and isolation. Heres the oil puddle it is over time but the very wet part is new1000007778.jpg
 

89Suburban

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So I have a pretty good oil leak I have taken off the view cover and it looks dry any suggestions 07 yukon denali 6.2l AWDView attachment 426285View attachment 426286View attachment 426287View attachment 426288View attachment 426284estions?

If it is the rear main it would be slinging off the front of the flywheel where you can't see. I have the same issue. Inside that inspection cover looks dry but the outside looks like hell. I am losing about 1/2-3/4 quarts a week. I plan on replacing the oil pan and gasket to see if it at least cuts that in half. I have already replaced the VLOM, VC gaskets and block off plate.
 

Larryjb

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If it is the rear main it would be slinging off the front of the flywheel where you can't see. I have the same issue. Inside that inspection cover looks dry but the outside looks like hell. I am losing about 1/2-3/4 quarts a week. I plan on replacing the oil pan and gasket to see if it at least cuts that in half. I have already replaced the VLOM, VC gaskets and block off plate.
Maybe not the rear main, but could be the rear cover which is common. In this case it won't likely sling off the flywheel, but can still drain down the back of the engine. This is very difficult to see.

In any case, fixing the rear cover gasket is the same process as the rear main and should be done together anyway.
 

Geotrash

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All great insight here, and I'll add one more piece. *If* you decide to either have a shop do this or tackle it yourself, spend the extra $500 to have a new torque converter with a billet cover installed on the transmission. Oh, and have them replace the oil gallery barbell, too. Should be about $1500 out the door. The TC is a weak link on the 6L80 that will take out the rest of the transmission, lines, and coolers when it fails, by spreading shrapnel through the system.
 

j91z28d1

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I just saw something the other day saying the billet bar bells aren't the way to go, to tight of a tolerance needed for the cheap level of price and if you cut a o ring on the way in, you'll never know it but it's bypassing oil the whole time. their suggestions was to use a new oem plastic one. no one can remember one actually falling and oem quality for 7$.

seemed to make sense when I read it.
 

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