Rear Main Seal Leaking

Oil leaking "in" your valve cover? Where is the oil at/coming from? And, to answar your question, rear main seal is a real job! Requires removing transmission, flex plate/fly wheel! It is the crank shaft seal, on the "rear" of the engine!

black oil or red oil
if red it is a torque converter seal and the transmission will have to be removed
use a professional auto transmission specialist shop
black oil is sump oil and can be from a rear main seal or leaking from a rocker cover gasket and running down to under the bell housing making it appear as a rear main seal

This may be from excessive pressure in the sump from blow-by from the compression process . It is from a blocked PCV valve that is not equalising that pressure. I have also known oil leaks to happen because the rear main bearing cap is leaking oil past the join around the bolts (loose) or no sealing compound used in assembling the rear main bearing.. I would look at the PCV valve as it is the cheapest test first.. Check that the oil is not coming from the front gear box seal or torque converter seal.

If it's leaking from inside the engine then it would be coming from the valve cover. The cover gasket seal is no longer sealing properly. If oil is leaking down under the car then check around the oil pan, could be gasket or rear main oil seal or front oil seal.

sounds like a rear bell housing seal

ENGINE MISSING CAN BE WEAK COIL.BAD PLUGS AND WIRES.REPLACE DISTRIBUTOR CAP AND ROTOR.FUEL FILTER STOPPED UP ALSO FUEL INJECTORS CLOGGED UP CAUSES MISSING.CHECK UNDERNEATH CAR WHILE IDLING.IF YOU LOSING A LOT OF OIL.FRONT CRANKSHAFT SEAL OR REAR MAIN SEAL LEAKING OIL.LEAKING VALVE COVERS.DO A COMPRESSION TEST.AND CHECK CONDITIONS OF SPARK PLUGS.IF PLUGS SOAKED IN OIL.VALVE GUIDES + SEAL LEAKING OIL IN COMBUSTION CHAMBER.

Be sure it is the rear main seal,there is a cam plug that could be leaking,but if it is the rear main oil seal leaking,then I suggest removing it,and installing a rear main repair sleeve,this will give it a new surface to ride on,the crankshaft may have a groove cut into it from the oil seal,this will remedy the problem.If this was at all helpful,please rate,thank you.

A leaking rear main seal will not cause your transmission to leak.

The transmission has its own seal and should not leak because of the engine rear main seal.

Due to the labor involved in replacing the rear main seal on the engine, it is best if you replace the front transmission seal at the same time if possible.

Installation varies on different vehicles but the principles are the same.

CHECK TO SEE IF YOUR TRANSMISSION PAN GASKET IS LEAKING/IF NOT CHECK ALL HOSES AND LINES/IF NOT REPLACE YOUR REAR MAIN SEAL.

It is the oil pan gasket all you have to do is drop the oil pan clean the bottom of the engine block and the surface of the oil pan and install the oil pan again. a very simple process. Make sure that it is not the rear main crank seal that is leaking. If it is the rear main then you will have to remove the tranny to replace the rear main seal.