Help me identify the source of these oil leaks

[showaski]

as the title says, lets play a game of identify that leak! Not only will I get your opinions, but this will help me confirm where I believe their coming from too. I'm about 99% sure the rear main seal is leaking, but I can't seem to exactly pin point where the front leaks are coming from.

Your responses would be greatly appreciated!

[1996 328ti]

My money is oil filter housing.

To help with my leaks I sprayed a generous amount of simply green over leaks at a hand held car wash. Then cleaned the motor as best I could. That helped me identify 2 different leaks. One oil filter housing and the other power steering.

[Marv17]

Common oil leak locations are the oil filter housing (cheap small gasket but hours of work to do, easy tho), power steering hose, valve cover gasket, and oil pan. I was going to say vanos as well but forgot the m4x doesn't have that Haha. Have fun replacing those gaskets. Remember to lube or oil up the gaskets when you put them it. It'll help them "sit" in better.... Oh, and don't forget the o-ring for the oil dip stick

[xxxJohnBoyxxx]

PM sent back about CCV, now that I see this thread and from there pictures it looks like a oil filter housing leak right where the one way o-ring pipe goes between the oil filter housing and block.

I have fixed 3 oil filter housing leaks on 318's and they look like this with the oil everywhere. Get on that motor with a good detergent or engine clean with a brush. Clean the motor well then go for a quick ride around the block and park on a dry clean area of the driveway. You should see a leak right below the oil filter area where it connects to the block.

This is a pressure leak so when these start leaking it pumps out a lot of oil since it is under pressure. That oil will leak to the oil pan all the way back to the transmission. the fan and air blowing under the car will blow that oil everywhere.

Best, John S

[1996 328ti]

I also found this leak to be worse when it got cold out.

[showaski]

Thanks for the responses guys. I've replaced the valve cover gasket along with the spark plug tube seals a couple months ago. I've checked the valve cover area several times and it's definitely not coming from there. I was suspect of the oil pan too.

I'll check the oil filter housing gasket as some of you mentioned on the next oil change (it's coming up very soon).

As for the PCV ... I've left it alone since buying the car from the previous owner. The PCV is plugged (basically disconnected from valve cover and plugged/blocked), and the the valve cover breather is vented to the atmosphere through an oil catch can. This would seem ideal, but maybe this is causing pressure in the crank?

I wish there were more info on the PCV system for these cars. I searched to the end of the internet and found little to no information regarding the PCV system on the M42/M44 engines. All the information I found only talks about the single vacuum hose from the valve cover to the PCV on the intake manifold. You would think there is more to the PCV system than just that? *shrug*

[showaski]

Will the oil housing seal cause the oil to leak onto any hot or warm surfaces? I'm just wondering because I can easily see and smell smoke from oil burning on a hot surface. It flows from under the hood and around the car from underneath.

[1996 328ti]

Clean up the motor. It will help identify the leak.
And I smelled oil burning from my oil housing leak.

[xxxJohnBoyxxx]

Ok I PM'ed the solution. For board members this is a boosted car with the CCV valve blocked. My new Metric motor leaked from all seals without a triple PCV system installed. The solution is using 3 one-way valves so the engine has vacuum during all conditions except under boost. When the engine goes into boost the CCV needs to be blocked because we don't want boost being blown into the crankcase plus the crankcase needs to be open to atmosphere so it can dump "blow-by" vapor. Without this system on my car I would lose over a quart of oil per tank of gas. With the system I lose maybe 1 quart per oil change (7,500 miles) and that is turbo seal leak since I'm running too much oil pressure/flow to the turbo. I'm going to fix this when it cools off outside.