Being in a cold weather climate, how could I justify running 15W-40 Rotella T4? Doesn't sound like any cold weather protection to me.

I'd like to believe its not the rear main seal. It's too slow of a leak.

Where else would the oil be coming from in that area?

Also, open the access panel and look inside to see if there is build up of oil in the bell housing.

I live in Illinois, travel frequently to MN, and I run Rotella T6 all year. You can add engine break in additive to any oil you’d like, but the T6 works great.

How fast or slow something leaks does not have anything to do with Where it is leaking from.

i would be nervous about running a 15w40 in the winter. especially with temps below zero. i run 5w40 all year long. i also run synthetic in all my rovers. even the '96. it currently has 230,000 miles on it.

I'd like to believe Rovers don't leak at all...


Could very well be the rear main, or could be blowing down the back from a valve cover.


That's a bad spot to have a leak for troubleshooting purposes...It does look like its saturated in the seams...


This may be one that takes some time to find and you may want to wait till spring.

I have 01, 221,000 miles, been running Rotella 15-40 in it for 7 years. I've never changed the oil pump.

I think it could be valve covers, or even the rear of the lower intake.
But, that oil from the valve covers would run down the outer rear of the block and trans.
I would think you would see oil from each side of the trans on the back sides of the oil pan and trans.
The pic looks like the trans is clean of oil, except in the center, so just the rear main seal.
But, given how common valve cover leaks seam to be on these, they are probably leaking too.

Should I just give it some blue devil rear main sealer? Will that do the trick for the valve covers? I can go to auto zone and do that today.. I'm about to go on a 520 mile drive back to college, would prefer not to take big risks with it.

As for the oil, 15W just won't do. My only option then seems to be Rotella T6 fully synthetic. Why switch from Mobil 1 synthetic to Rotella T6 if they are both fully synthetic, I thought the whole point of switching to Rotella was that you can buy the dino one that works best with these engines? Thanks for everything so far guys.