Rear Main Leak. Thicker Oil?

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jamie2

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I have a rear main leak on my 2001 Yukon XL in its starting to get worse, looking at going to a thicker oil to try and slow down the leak. I live in Central TX so temps are warm most of the time to say the least. 5W30 is just too thin any ideas on what oil might work best?

Jamie
 

Goodinblack

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You really need to fix the problem.

Thicker oil may not be a proper patch.
 

Chiggy

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How sure are you that it's a rear main leak? That's not terribly common on one of these LS based engines but I guess it's not impossible. I'd think that the oil pressure sensor or something close is leaking. That's at the back and damn near under the intake manifold by the firewall. I had to use a mirror to replace the last one I messed with. It had been replaced before and was leaking oil
 
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jamie2

jamie2

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GM dealer confirmed its the rear main. It is common according to several shops I have talked to about the issue. I know the leak needs to be fixed but the price id in the range of 500 to 800 bucks (1200 if GM does it) to fix the problem. That's why I'm asking about thicker oil. I have had this XL since it was new so I'm not about to screw it up.

Jamie
 
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TxTooTall

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Are you sure that its not leaking around the oil filter? Rear main seals are a rare thing to have an issue with

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01yukontx.

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Thicker oil may be the source of a larger problem.extra wear from the time it takes to reach critical areas.tight tolerances in these engines demand proper viscosity.I know it is hard to spend on the fix,maybe just increase your oil budget money and stick with 5w30 till you can fix it.my manual says do not use 20w50 oil.....just friendly advice from a broke oil leaky Texas Yukon owner.

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jamie2

jamie2

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Are you sure that its not leaking around the oil filter? Rear main seals are a rare thing to have an issue with

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I have changes the oil several times not an oil filter issue. I might be new to this forum but I'm not new to working on cars. This is what happens, see below.

One the back of the block below the crack is a casting lip, the oil runs out of the rear main down to that casting. At this point it looks like the oil pan gasket or the oil filter is leaking, oil also comes out of the bottom of the trans housing. Makes a real mess, I wish I had access to a lift and the tools needed and I would do it myself. This is the only way my wife has to go so it looks like I'm going to have to pay someone to fix it for me. We have 4 kids so it cant be down for very long.

Jamie

---------- Post added at 03:08 PM ---------- Previous post was at 03:06 PM ----------

Thicker oil may be the source of a larger problem.extra wear from the time it takes to reach critical areas.tight tolerances in these engines demand proper viscosity.I know it is hard to spend on the fix,maybe just increase your oil budget money and stick with 5w30 till you can fix it.my manual says do not use 20w50 oil.....just friendly advice from a broke oil leaky Texas Yukon owner.

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True, bearing tolerances was my main concern. Going to keep adding oil until Jan more than likely.

Jamie
 

01yukontx.

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As a husband/father that is financially challenged,I share your pain.lol.Good luck with the fix.

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08grey

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Try Lucas. Forget what you read. It's great for your motor and will slow leaks. Substitute i qt for it.
 

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