Rear Main Leak. Thicker Oil?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

jamie2

TYF Newbie
Joined
Mar 2, 2012
Posts
12
Reaction score
2
Location
Texas
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

I Like Tacos
Supporting Member
Joined
Oct 27, 2011
Posts
22,295
Reaction score
3,040
Location
Dirty South
You really need to fix the problem.

Thicker oil may not be a proper patch.
 

Chiggy

Full Access Member
Joined
Nov 7, 2013
Posts
144
Reaction score
2
Location
Kansas City, MO
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
 
OP
OP
jamie2

jamie2

TYF Newbie
Joined
Mar 2, 2012
Posts
12
Reaction score
2
Location
Texas
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
 
Last edited:

TxTooTall

Member
Joined
Oct 18, 2013
Posts
36
Reaction score
3
Location
League City, Tx
Are you sure that its not leaking around the oil filter? Rear main seals are a rare thing to have an issue with

Sent from my SAMSUNG-SGH-I337 using Tapatalk
 

01yukontx.

TYF Newbie
Joined
Dec 16, 2013
Posts
7
Reaction score
0
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.

Sent from my SCH-I110 using Tapatalk 2
 
OP
OP
jamie2

jamie2

TYF Newbie
Joined
Mar 2, 2012
Posts
12
Reaction score
2
Location
Texas
Are you sure that its not leaking around the oil filter? Rear main seals are a rare thing to have an issue with

Sent from my SAMSUNG-SGH-I337 using Tapatalk

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.

Sent from my SCH-I110 using Tapatalk 2

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

Jamie
 

01yukontx.

TYF Newbie
Joined
Dec 16, 2013
Posts
7
Reaction score
0
As a husband/father that is financially challenged,I share your pain.lol.Good luck with the fix.

Sent from my SCH-I110 using Tapatalk 2
 

08grey

Full Access Member
Joined
Jun 17, 2012
Posts
4,596
Reaction score
725
Try Lucas. Forget what you read. It's great for your motor and will slow leaks. Substitute i qt for it.
 

Forum statistics

Threads
132,469
Posts
1,868,778
Members
97,179
Latest member
epseventhletter
Top