I have a 2003 Tahoe with just over a 100k on it. I noticed oil around the driver side valve cover and all over the surrounding area. I replaced both the valve cover gaskets and solved that problem. now I am noticing oil from underneath around the filter and oil pan area. Any ideas on where it might be coming from? I have heard and read it could be the oil pan gasket or the rear main seal but want to find out for sure before I go to replacing items.

 

Welcome to the forum.

Best thing to do to determine the location of the leak is to clean the area thoroughly with some brake cleaner. Then recheck after some driving.

 

I second the cleaning and checking, do make sure the filter is on snug... unless you are doing your own filter changes, you don't know how tight the technician that changed it put it on... it can be too tight, but it can also be loose, I'd make sure its at least hand tight...

You can check /tighten the oil pan bolts but don't over tighten them....

Tighten

Tighten the oil pan-to-block and oil pan-to-front cover bolts to 25 N·m (18 lb ft).

Tighten the oil pan-to-rear cover bolts to 12 N·m (106 lb in).