00 740iL - Oil leaks

I have changed the valve cover gaskets and I still have a leak. What next?

First, you have to find the leak.

Where is it coming from? If you can't pinpoint it with a flashlight, degrease the general area around where the leak is coming from, let it dry, start the motor, and look for the leak. Try not to get water on any electrical components in the motor.

Keep in mind, that oil does not evaporate and what you are seeing could be residual oil left over from when the valve cover gaskets actually were leaking.

UPPER TIMING COVERS are almost always a source of an oil leak. Also check the oil lines from the filter housing to the engine block. And these cars almost always have a power steering hose leak. All of these are common on the E38.

Good luck!

at most auto parts stores, you can buy flourescent liquid dye that is specifically for oil. they make it as well for ac systems and coolant. make sure its for oil if you do get it.

if you decide to use flourescent dye, again degrease the engine and go about running it to find where the leak is. you can usually buy an LED ultra violet light at the parts store as well which will illuminate the dye where the oil is leaking. this has been the easiest way to find oil leaks i've found. it could even be the power steering leaking. mine is and i thought for the longest time the engine was leaking. you may also use the dye for oil in the power steering. just make sure and read the directions on how much to use, its not much.

Originally Posted by balance

First, you have to find the leak.

Where is it coming from? If you can't pinpoint it with a flashlight, degrease the general area around where the leak is coming from

Simple Green is great for doing this. It really lifts up grease & most of it will just wash off without any rubbing. I say wash off, but I don't use a hose to do this - I just fill a spray bottle with water & spray the Simple Green & grime off the engine. This is a pretty easy way to do a basic clean to see if that area is still leaking oil.