Its most likely the rear main seal... the "gear thingy" is the flywheel or flex plate. The leak looks like its coming off the transmission bell housing and dripping off the bolt because its the lowest part. The rear main seal requires removal of the transmission and other components.
1995 BMW M3 5 Speed Coupe, 3.0 S50B30, Cosmos Black/Hellgrau Vader, Shrick Camshafts, New Vanos
Dinan Cold Air Intake, Ireland Engineering Front and Rear Strut Bar, Turner Motorsport Chip, EWS Delete
BBS RC 303 Genuine, 24 lb Injectors, Tuned for 93 Octane, StopTech Rotors, Bilstein Shocks, H&R Race Springs
Continental DWS 06, Eibach Front and Rear Sway Bars, Turner Motorsport Rear Camber Arms, TM RTABs.
Could it be possible that it is the oil pan gasket leaking. Or definitely the rear seal?
2002 525i
Most likely it's the oil filter housing leaking and running down the oil pan to the back of the engine. It could also be the oil pan gasket its self. The least common seals to fail on that engine are the front or rear crankshaft seals.
At that location it could be anything that is above that point. As said before the most likely candidate is the oil filter housing gasket. If you need to find the source, degrease the entire engine and trace the source back up as it reappears.
You will have to look around the oil pan and determine if oil is leaking from there. Check on the passenger side too and if it is leaking then that's your oil pan. For oil filter housing gasket, look over at the driver side and around the alternator + power steering pump area to see any oil leak around it. That pretty much tells you of oil filter housing gasket is leaking. The leak extends all the way on the side of the oil pan to the transmission. If that's not the case then most likely your rear main seal is leaking.
could a broken oil return line from the ccv also cause this?
2002 525i
Thanks all for your responses. I'll investigate further. But this was the only leak I found. Engine was fairly clean. I'm picking it up on Sat.
I have a similar leak. And have been monitoring it for the past couple of days. It doesn't appear to be the ofhg. But I could be wrong. It's been parked for the last week. But 3 days ago. I threw a piece of cardboard under it. It's dripping in the same spot. Continuously every day without being started. Is this a sign of the Rms?
2002 525i
Most likely or check your oil pan all the way around.
Here's a pic. About 4 days worth. Hopefully just the oil pan gasket. Figured the rms wouldn't be constant??? Higher point than the sump...no?? Or it doesn't matter
Last edited by Trainwreck914; 11-19-2015 at 09:48 AM.
2002 525i
Came across something called the sneaky Pete. It's a rear main seal tool. Anyone ever heard of or used it. Would it work on the e39?
2002 525i
How many miles are on your car and when was the last time your oil filter housing gasket was replaced. Look down behind the filter housing along the engine block. If there is any oil that you see start with the filter housing gasket. And clean the hell out of the engine. Then check for leaks again after driving for a day or two.
In my experience an M54 needs new filter housing gaskets, crank case vent valves and valve cover gaskets every 80-90 thousand miles. Oil pan gaskets can last longer. I have worked on many 300k cars still leak free from the rear main seal. I'm not saying that yours isn't leaking. I'm just saying for an engine with so many common oil leaks, it seems odd that yours is only leaking oil from the most reliable seal.
Picked up the car about a month ago. No history but the price was right. Dash says 153k. But not sure how true it is as someone changed the cluster. Just removed the fan clutch because it was bad. I can do the ofhg while I'm in there, plan on doing the cooling system anyway. But if it were that gasket, wouldn't there be signs of oil under it? I don't see any signs. The car has been sitting a week now. With the same piece of cardboard under it. And the spot is getting bigger. It's dead center over the union between the motor and trans...
2002 525i
I doubt it's the rear main if it continues to leak when the car has been sitting for a while. So I'm going to agree with ither the oil pan or oil filter remote lines to block.
What part of the bay area you in, I'm in Union city. Go to a pepboys and get a leak detector kit. The kit comes with a florescent visible liquid and florescent light, just pour the liquid in your crankcase, drive for a bit then go CIS on the block with the light.
Last edited by Msport540; 11-21-2015 at 10:27 AM.
Renting: M62 G.A.S. Master timing tool kit & M62 KTC crankshaft holding tool
That's good to hear. I was hoping it wasn't the rms. Kinda figured since it continues to drip while parked. . But wasn't really surE.
2002 525i
Trainwreck or IgotBMW,
Are you still around forum?
I have a 2004 X3 2.5i M54 with 85K miles, it also leaks at that particular bolt.
Did you ever find out what the cause was?
Was it OFH Gasket?
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