2002 Chevy Tahoe 2wd 4.8

[Manny Lopez]

Don’t know if I’m posting in the right place , new here but just wanted to get some help . I noticed this oil leak very small leak , but don’t know where it’s coming from thinking it’s the rear main cover or the seal but i did an oil change the other day noticed one side of the oil filter tends to get wet nothing else really besides that . Truck has 158,000 miles on it . Don’t know if it’s the oil filter adapter or the rear main (from what I have read) I’ll upload pictures soon . Any help would be great !

 

[OR VietVet]

If rear main seal leaks you tend to not see it on the outside of the trans bell housing unless it is puking. Could be back of intake or valve cover on that side that is leaking from above. Very well could be the oil filter adaptor seal area or the oil filter itself.

 

[Fless]

Or it could be the oil blockoff plate (or lines) just above the oil filter.

 

[Larryjb]

When I did mine, I more leaks from the rear cover rather than the rear main seal. However, if you have to replace the rear cover seal, you'd be a fool to not do a $5 rear main seal at the same time!

That said, I'd do the easier gaskets first:

1. The oil cooler block off plate is a common leak and is easy to do.
2. The oil pan gasket is not too bad either, especially on a RWD. This is also a good time to do the seal for the oil pick up tube.
3. The oil pressure sensor seal is a little tricky to get at, but is possible withing removing the intake manifold. Of course, it may be a good idea to replace the intake manifold and do the valley gasket. (I'm familiar with the 5.3L, and am assuming the 4.8 has a valley gasket as well.)

After all this, you'd then have to decide whether to get the rear main done by a shop, or you take it on yourself. Being RWD it wouldn't be too bad to do. I did it on my 4WD and had to remove a transfer case and driveshafts. That was no fun.

IF you have good basic mechanical skills (you know how to do things safely, you know how to use a torque wrench, you know how to remove rusted on bolts, and wish to learn a few new words that can never be shared with children, doing the rear main isn't that bad to do and will save you a lot of money. I did mine 10 months ago and haven't had any leaks yet. Here's a long thread of what I went through: https://www.tahoeyukonforum.com/threads/rear-main-oil-seal.117639/

 

[JonnyTahoe]

Don’t know if I’m posting in the right place , new here but just wanted to get some help . I noticed this oil leak very small leak , but don’t know where it’s coming from thinking it’s the rear main cover or the seal but i did an oil change the other day noticed one side of the oil filter tends to get wet nothing else really besides that . Truck has 158,000 miles on it . Don’t know if it’s the oil filter adapter or the rear main (from what I have read) I’ll upload pictures soon . Any help would be great !

Yes Manny you have posted in the right place. Engine and Drivetrain.

 

[Tonyrodz]

Don’t know if I’m posting in the right place , new here but just wanted to get some help . I noticed this oil leak very small leak , but don’t know where it’s coming from thinking it’s the rear main cover or the seal but i did an oil change the other day noticed one side of the oil filter tends to get wet nothing else really besides that . Truck has 158,000 miles on it . Don’t know if it’s the oil filter adapter or the rear main (from what I have read) I’ll upload pictures soon . Any help would be great !

Do you have a pic of the location of the leak? That might be helpful.

 

[clandr1]

I had this same problem about a year ago. I started with replacing the oil cooler blockoff plate gasket, but it didn't fix it. I took it to a shop and they confirmed it was the rear main seal that was leaking, so I had them replace it to the tune of about $800.

Three years ago I replaced the oil pickup tube o-ring, and the oil pan gasket, so I was able to reasonably rule my oil pan gasket as the source of the leak.