To check the valve covers you just need to look at the seam where they meet the head. You could also look in the spark plug wells. I don't think it is either. If the valve cover gaskets where leaking, chances are you would smell oil burning after driving. If the spark plug wells where leaking you would most likely foul out the plug.

As far as I know the valley pan will only leak anti freeze. There are no oil galleys there.

I really suspect it is the oil return line that goes down the back of the engine from the oil sep to the oil pan. IIRC looking through the front passenger side wheel well with the wheels turned to the left gives a pretty good view with a bright light. Again, it's tight but if the engine is wet on that passenger side rear corner you have found the leak.

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2007 Suzuki Vinson 500 4X4
2007 Toro 6.5hp
2006 BMW X5 4.4 ltr (his)
2001 BMW X5 4.4 ltr (hers)
1994 Honda XR650L
1984 Honda XR80

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