Rear main seal leaking, causes

[Cheesetoast]

see below, changed the oil and noticed it dripping pretty bad from here.  the dripping has almost stopped now, but was one drop every 5 seconds.

rear main seal was replaced a few months ago when the clutch was done.
now i'm looking for causes of this, here's the theorys

-running 20psi boost, could this have somehow blown that seal?
-ran 250ml of rislone through before i changed the oil, ran for about 200km with it in, put it in, dip stick was pretty high, but bottle said dont' worry about overflowing the crankcase.
-rear main seal was put in wrong, or shoudl have been put in with some gasket maker to reinforce it.

[fspGTD]

First - make sure it's not dripping down from the top, IE: anything leaking out the side of the head like from the valve cover or from the oil pressure sender?  Oil dripping down the side of the block from the top would end up at the bottom down there too.

Second - double check it is engine oil and not tranny fluid (should be able to tell by color if the engine oil is black and tranny fluid is lighter in color and also by smell.  From the pic it does look kind of dark which suggests motor oil though, but do make certain.

Then, if you are sure it's engine oil, and sure it's not coming from the top of the head, it's got to be coming from the rear main seal.  It is possible it could be installed wrong (this is a tricky seal to install correctly, as the lip can "fold" out when pushing the seal in - ask fatmobile about his special installation tool to help prevent this), but in that case it seems like it would have been leaking ever since it was replaced.

Easiest to try running the oil level at the correct/low level and see if the leak persists, maybe flush solvent down to get rid of the oil oil residue to be certain it is still coming out beforehand.  Then only at last resort remove the transmission and all the clutch parts needed to get to the rear main.  If you get into replacing the seal, when you have removed the old seal, inspect the sealing surface of the crank to make sure it is smooth - without burrs or deep grooves.  Burrs can be polished off with some emery cloth.  For deep grooves, the only thing easy I can think of is to install the seal at a slightly different depth to try and get the seal to ride at a different spot.  I would also recommend using motor oil to lubricate the seal before re-installing, not grease (which is higher friction and can be more abraisive.)

Also if you peel off the tranny and clutch disc, check for evidence of oil coming out around any of the pressure plate to crankshaft bolts.  One or two of those bolts plug a crankshaft oil galley.

[Cheesetoast]

definately not coming from above, everywhere i can see is clean.
engine oil for sure.
nothing from the sensers
if the seal was installed wrong, wouldn't it have leaked right away? it's been a few months.
I may just leave it, a new clutch disc is not very expensive, if it starts slipping, i'll know why.  I'm talking with my mechanic now about my options, could some gasket maker be used as well to strengthen the seal?

First - make sure it's not dripping down from the top, IE: anything leaking out the side of the head like from the valve cover or from the oil pressure sender?  Oil dripping down the side of the block from the top would end up at the bottom down there too.

Second - double check it is engine oil and not tranny fluid (should be able to tell by color if the engine oil is black and tranny fluid is lighter in color and also by smell.  From the pic it does look kind of dark which suggests motor oil though, but do make certain.

Then, if you are sure it's engine oil, and sure it's not coming from the top of the head, it's got to be coming from the rear main seal.  It is possible it could be installed wrong (this is a tricky seal to install correctly, as the lip can "fold" out when pushing the seal in - ask fatmobile about his special installation tool to help prevent this), but in that case it seems like it would have been leaking ever since it was replaced.

Easiest to try running the oil level at the correct/low level and see if the leak persists, maybe flush solvent down to get rid of the oil oil residue to be certain it is still coming out beforehand.  Then only at last resort remove the transmission and all the clutch parts needed to get to the rear main.  If you get into replacing the seal, when you have removed the old seal, inspect the sealing surface of the crank to make sure it is smooth - without burrs or deep grooves.  Burrs can be polished off with some emery cloth.  For deep grooves, the only thing easy I can think of is to install the seal at a slightly different depth to try and get the seal to ride at a different spot.  I would also recommend using motor oil to lubricate the seal before re-installing, not grease (which is higher friction and can be more abraisive.)

Also if you peel off the tranny and clutch disc, check for evidence of oil coming out around any of the pressure plate to crankshaft bolts.  One or two of those bolts plug a crankshaft oil galley.

[fspGTD]

Yes it does seem odd that the seal would not have leaked ever since it was installed.

I don't see how you can do any quick fix with gasket maker.  Gasket maker/sealer would only be helpful to seal the stationary part of the seal where it presses into the aluminum seal carrier.  It has "ribs" along its outside diameter that should seal just fine with the aluminum seal carrier, as long as there are no gouges in the seal carrier.  To get at the seal you'd still need to remove the tranny and flywheel/clutch/pressure plate, which is there your labor cost is.  If you do that, you might as well remove the old seal and inspect it along with the crankshaft sealing surface and surface of the aluminum seal carrier, as well as try and diagnose where it was leaking, plus go ahead and install a new seal (which costs only $4 or so for the part.)

[Cheesetoast]

so here's my next question, has anyone had rear main seal leaks assocatiated with increased boost from stock? i was told if there is ring blow by, this could happen.

[QuickTD]

Usually when I change my oil on ramps, I end up dripping a bunch of oil down the bottom front edge of the block when I remove the oil filter, The oil kind of pools on top of the oil pan flange on the block and when I take the car off the ramps onto level ground it drips for a few minutes. Most of the oil tends to run down the bell housing, exactly as pictured. I'd wait a day and see if its still dripping before I condemned anything.