Rear Main maybe??

[C10CDOVA]

 So I’ve got a good leak going somewhere. I’ve narrowed it down to either being a bad oil Pan gasket or rear main seal. Maybe you guys can help me pin point it. I’m getting oil drips off my starter, oil pan and oil filter. No drips off of the flex plate. No leaks from the oil sending unit, heads or valve covers. I know it’s not much of a description but that’s all I got. Anything helps

[MIKE S]

Does the back of the flywheel have any streaks like it has been throwing oil like a fan?

[frotosride]

So if I'm reading your post right, you have oil dripping from both sides, starter (passenger) oil filter(drivers). Since you said the valve cover gaskets ain't leaking that rules them out. If it was the rear main seal the flex plate and torque converter would make it obvious. Here's what's left...

1:There is one common thing for both sides and that's the distributor gasket and or rear China rail of the intake manifold.
2:Aside from that the passenger side could be the dip stick.
3:Drivers side: oil fill cap leaking and draining down the valve over, PCV grommet leaking, oil pressure sending unit (for oil pressure gauge) fittings or the sending unit could be blown, this is common as mine leaked for years before I decided to replace it.

[Ed4all10]

I am by no means an advocate for the old “Mechanic in a can” fixes, but I have used a product in our shop called AT 205 reseal. It is basically a seal conditioner that you add to your motor oil. It only costs a few bucks, and I have had success with using it in customer’s vehicles that we are trying to nurse along, or maybe a main seal replacement was out of their budget range. Either way, it won’t hurt, and if it stops the leak, great. If not, you are still back where you started.

Just make sure you follow the directions, and drive it for a little bit before you write it off as not having worked. Good luck.

[JAH]

Just my $0.02...


I'd take some Purple Power (or some other degreaser...Simple green, etc.), and a water hose, and get everything underneath nice and dry.

...and then watch it every day for the next week or two.


The underside of trucks, especially old trucks, are a very "dirty air" area in regard to aerodynamics.  So, in my humble experience, fluids can flow all kinda' ways down there.  This, and liability, are the two most common places where s--- can roll uphill.

Happy hunting.