Oil leak

bureau13 · 01-21-2021, 10:34 PM

This car (2006 325i w/ N52) is at that age where everything that's going to leak oil is leaking oil. The first thing was I started seeing oil in the coolant. I replaced the oil filter housing gasket, and that seemed to fix that issue. Then the car threw a belt, I noticed it was pretty greasy and the front of the motor started getting really goopy, so I replaced the valve cover gasket and the other associated seals and gaskets that you generally do at that time. I found a drip right onto the belt, where it presumably was getting thrown around, which was one of the cam position sensors was loose, so I replaced those, and no more drips there. The front of the motor is still getting oil on it, and the belt is still occasionally coming off (yes, I put on a new one). I can't tell where it's coming from. I do think it's getting on the belt and getting flung around, I see the front of the motor, the front/underside of the alternator, and the innermost side of the air box are all getting wet with oil. I thought maybe I did a bad job on the oil filter housing gasket, but I took a closer look with the intake manifold off (while replacing starter) and it doesn't seem to be coming from there. Is there another typical candidate? Crank seal maybe? But generally those seep down, not onto the belt, in my experience with other cars.

iansexotics · 01-21-2021, 10:36 PM

Carful the belt could get sucked in motor if you don't have crank seal protector plate could be that front seal my belt got oil on it from it

Efthreeoh · 01-22-2021, 05:27 AM

Google N52 broken head bolts. Your engine may be suffering from that condition.

bureau13 · 01-22-2021, 09:16 PM

I've heard of that belt-getting-sucked-in thing. Sounds crazy, but apparently it's happened quite a bit.

If this car has broken head bolts it's going in the garbage. It's not worth the effort to fix that. Ugh...

Bmw1939 · 01-22-2021, 09:23 PM

Buy some of the leak DYE. Put it in the motor and use a blue light to track. Youll find it in 10 seconds.

IllSic_Design · 01-22-2021, 09:51 PM

Most likely front crank seal.

I had a guys car that I worked on that I changed the OFHG and fixed the leak. His car started leaking again (like year later) onto the belt and shredded a few so he had a shop look at it. They said it was either ofhg or valve cover gasket. He then had me look at it. I had already changed the valve cover gasket previously and also the ofhg and could see that they were NOT leaking and told him it was probably the crank seal, but he wanted me to try the OFHG since it wasn't too expensive. Well that didn't stop the leak and the shop kept suggesting he do the valve cover so I told him to have them do it if they think that's it. Well it wasn't, so finally he had them change the crank seal and no more oil leaks. Of course the shredded belt(that happened 2-3 times) took out the seal, but he didn't want to believe it was bad/pay for the expensive labor to possibly fix it.

Bmw1939 · 01-23-2021, 10:55 AM

Isnt the crank seal just behind the pulley? Easy fix no?

bureau13 · 01-23-2021, 12:14 PM

The dye is a good idea....I didn't know it existed for oil! I've used similar for coolant.

The crank seal should be behind the pulley but I'm not sure how difficult it is on this car. It's a fairly major job on some cars though. It's basically a timing belt job on my 928, which is fairly major.

01-21-2021, 10:34 PM	#1
bureau13 Private 3 Rep 56 Posts Drives: 2006 325i 6-speed Join Date: Nov 2019 Location: South Florida iTrader: (0)	Oil leak This car (2006 325i w/ N52) is at that age where everything that's going to leak oil is leaking oil. The first thing was I started seeing oil in the coolant. I replaced the oil filter housing gasket, and that seemed to fix that issue. Then the car threw a belt, I noticed it was pretty greasy and the front of the motor started getting really goopy, so I replaced the valve cover gasket and the other associated seals and gaskets that you generally do at that time. I found a drip right onto the belt, where it presumably was getting thrown around, which was one of the cam position sensors was loose, so I replaced those, and no more drips there. The front of the motor is still getting oil on it, and the belt is still occasionally coming off (yes, I put on a new one). I can't tell where it's coming from. I do think it's getting on the belt and getting flung around, I see the front of the motor, the front/underside of the alternator, and the innermost side of the air box are all getting wet with oil. I thought maybe I did a bad job on the oil filter housing gasket, but I took a closer look with the intake manifold off (while replacing starter) and it doesn't seem to be coming from there. Is there another typical candidate? Crank seal maybe? But generally those seep down, not onto the belt, in my experience with other cars.
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01-21-2021, 10:36 PM	#2
iansexotics Private 2 Rep 79 Posts Drives: 2005 BMW 330 & 2007 BMW 335i Join Date: Jan 2021 Location: Clemmons, North Carolina iTrader: (0)	Carful the belt could get sucked in motor if you don't have crank seal protector plate could be that front seal my belt got oil on it from it
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01-22-2021, 05:27 AM	#3
Efthreeoh General 17207 Rep 18,697 Posts Drives: The E90 + Z4 Coupe & Z3 R'ster Join Date: May 2012 Location: Virginia iTrader: (0)	Google N52 broken head bolts. Your engine may be suffering from that condition.
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01-22-2021, 09:16 PM	#4
bureau13 Private 3 Rep 56 Posts Drives: 2006 325i 6-speed Join Date: Nov 2019 Location: South Florida iTrader: (0)	I've heard of that belt-getting-sucked-in thing. Sounds crazy, but apparently it's happened quite a bit. If this car has broken head bolts it's going in the garbage. It's not worth the effort to fix that. Ugh...
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01-22-2021, 09:23 PM	#5
Bmw1939 Lieutenant 268 Rep 464 Posts Drives: BMW 2011 328i, 2008 BMW X3 Join Date: Dec 2020 Location: CA iTrader: (0)	Buy some of the leak DYE. Put it in the motor and use a blue light to track. Youll find it in 10 seconds.
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01-22-2021, 09:51 PM	#6
IllSic_Design Colonel 2123 Rep 2,758 Posts Drives: 09 E92 335i Join Date: Jun 2016 Location: Northern California iTrader: (1)	Most likely front crank seal. I had a guys car that I worked on that I changed the OFHG and fixed the leak. His car started leaking again (like year later) onto the belt and shredded a few so he had a shop look at it. They said it was either ofhg or valve cover gasket. He then had me look at it. I had already changed the valve cover gasket previously and also the ofhg and could see that they were NOT leaking and told him it was probably the crank seal, but he wanted me to try the OFHG since it wasn't too expensive. Well that didn't stop the leak and the shop kept suggesting he do the valve cover so I told him to have them do it if they think that's it. Well it wasn't, so finally he had them change the crank seal and no more oil leaks. Of course the shredded belt(that happened 2-3 times) took out the seal, but he didn't want to believe it was bad/pay for the expensive labor to possibly fix it.
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01-23-2021, 10:55 AM	#7
Bmw1939 Lieutenant 268 Rep 464 Posts Drives: BMW 2011 328i, 2008 BMW X3 Join Date: Dec 2020 Location: CA iTrader: (0)	Isnt the crank seal just behind the pulley? Easy fix no?
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01-23-2021, 12:14 PM	#8
bureau13 Private 3 Rep 56 Posts Drives: 2006 325i 6-speed Join Date: Nov 2019 Location: South Florida iTrader: (0)	The dye is a good idea....I didn't know it existed for oil! I've used similar for coolant. The crank seal should be behind the pulley but I'm not sure how difficult it is on this car. It's a fairly major job on some cars though. It's basically a timing belt job on my 928, which is fairly major.
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