What is this and where does it go? wet spot_oil leak

335ivin · 12-05-2018, 09:24 AM

The other day I lifted my car to change out the transmission fluid and filter and noticed an oil leak. The problem here is that I don't know what the connection is or where does it come from. The leak is on the passenger side next to the catalytic converter.

I have owned this car for appx 8 years now and has been maintained by the BMW (under warranty & extended warranty). I do all my repairs and have been since I was in my early 20s. The problem now is that I know very little about BMW's, I have owned several Nissan's, Acura's, Toyota's and GM trucks.

CoffeeBean · 12-05-2018, 10:53 AM

Likely oil pan gasket. Check up above there where the gasket is. If it's not leaking much then let it be as it's not a cheap or easy job.

TheMidnightNarwhal · 12-05-2018, 11:55 AM

Yeah start from above. If it's not valve cover gasket or oil filter housing area leaks I wouldn't worry about it until it's leaking a lot. Make sure your belt is clean and dry.

Sometimes the oil filter housing can leak only on the backside. This is what happened to me and the way I dwelve into it was my coolant had just little amounts of sludge and oily film.

srey · 12-05-2018, 01:30 PM

It could be the oil pan gasket or the valve cover gasket. I wouldn't rule out your rear main seal either, but it's likely one of the other two. The OPG isn't difficult, per se, but it is time consuming. You would need to put the car on jack stands, hold up the engine with a support bar, drop the subframe, unbolting the steering rack as well, and then drop the oil pan. Some people say it's not worth it to DIY, but when I did it the car was not my only vehicle, so I took a few days and did it in chunks. It sure was nice to only be out tens of dollars and some of my time verses thousands of dollars to have a shop do it.

Efthreeoh · 12-05-2018, 02:15 PM

You have an oil leak?

335ivin · 12-05-2018, 02:25 PM

Quote:

Originally Posted by TheMidnightNarwhal

Yeah start from above. If it's not valve cover gasket or oil filter housing area leaks I wouldn't worry about it until it's leaking a lot. Make sure your belt is clean and dry.

Sometimes the oil filter housing can leak only on the backside. This is what happened to me and the way I dwelve into it was my coolant had just little amounts of sludge and oily film.

I would be shocked if its the oil pan gasket or the valve cover gasket, both of those were done 15k miles ago by BMW. I was thinking It could be the rear main seal. I'm going to let it ride for now and keep an eye on it.

TheMidnightNarwhal · 12-05-2018, 03:33 PM

Quote:

Originally Posted by 335ivin

I would be shocked if its the oil pan gasket or the valve cover gasket, both of those were done 15k miles ago by BMW. I was thinking It could be the rear main seal. I'm going to let it ride for now and keep an eye on it.

Ahh then yeah perhaps it is not those.

335ivin · 12-06-2018, 06:51 AM

Update

Last night after work I started looking into the mysterious leak, after looking at it closer I saw the inlet piping by the rear turbo soaked with oil. At first I thought it was coming from the oil supply line but saw that those areas were bone dry. I followed the inlet piping up and saw that it ties into the PVC valve. I removed the plastic that's on top of the valve and saw wet oil spots all around the PVC valve. With that said are these cars known for leaking oil there too? I'm going to install a catch can to see if this keep the oil out. I've attached a picture of the inlet piping to the rear turbo, how is that pipe clamped down? I don't see a clamp.

By the way, after doing all that investigation I realized the first pictures I posted are from the motor mount. lol

gbalthrop · 12-06-2018, 11:15 AM

Quote:

Originally Posted by Efthreeoh

You have an oil leak?

Either he has better eyes than either of us, or his photography skills need improvement.

George

335ivin · 12-10-2018, 02:02 PM

Quote:

Originally Posted by gbalthrop

Either he has better eyes than either of us, or his photography skills need improvement.

George

I took the pictures after I clean up the leaks.

OTO335i · 12-10-2018, 02:33 PM

Quote:

Originally Posted by 335ivin

Update

Last night after work I started looking into the mysterious leak, after looking at it closer I saw the inlet piping by the rear turbo soaked with oil. At first I thought it was coming from the oil supply line but saw that those areas were bone dry. I followed the inlet piping up and saw that it ties into the PVC valve. I removed the plastic that's on top of the valve and saw wet oil spots all around the PVC valve. With that said are these cars known for leaking oil there too? I'm going to install a catch can to see if this keep the oil out. I've attached a picture of the inlet piping to the rear turbo, how is that pipe clamped down? I don't see a clamp.

By the way, after doing all that investigation I realized the first pictures I posted are from the motor mount. lol

Your inlet piping looks to in pretty good condition also, either you're seeing oil that we can't see on it or you cleaned it up before taking the picture again... We can't help you out when looking at clean areas, If you cleaned them up then inspect again after a day or so to see if you notice new markings of an oil leak.

Both turbo inlet pipes (front & rear) do not require any clamps. They're engineered to slide over the turbo at the inlet and they have a rubber insert to help them stay in place, the rest of the inlet pipe is fastened to the engine along the way and helps it completely stay in place.

Efthreeoh · 12-10-2018, 03:06 PM

Quote:

Originally Posted by gbalthrop

Either he has better eyes than either of us, or his photography skills need improvement.

George

Well, oil retainment for BMW is more of a concept than a discipline. Just sayin'

gbalthrop · 12-10-2018, 03:48 PM

Quote:

Originally Posted by Efthreeoh

Well, oil retainment for BMW is more of a concept than a discipline. Just sayin'

WHAT a CONCEPT!!!

I'm coming from the Jaguar concept of undercarriage rust prevention by regular oil leak. It's actually a very cheap & effective means of being able to loosen 20- to 30-year-old fasteners, at least until things get entirely out of hand.

George

Efthreeoh · 12-10-2018, 08:51 PM

Quote:

Originally Posted by gbalthrop

WHAT a CONCEPT!!!

I'm coming from the Jaguar concept of undercarriage rust prevention by regular oil leak. It's actually a very cheap & effective means of being able to loosen 20- to 30-year-old fasteners, at least until things get entirely out of hand.

George

North Sea oil, the first anti-seize!

12-05-2018, 09:24 AM	#1
335ivin Private First Class 20 Rep 106 Posts Drives: 335i Sedan Join Date: Jan 2015 Location: Pearland, Texas iTrader: (0)	What is this and where does it go? wet spot_oil leak The other day I lifted my car to change out the transmission fluid and filter and noticed an oil leak. The problem here is that I don't know what the connection is or where does it come from. The leak is on the passenger side next to the catalytic converter. I have owned this car for appx 8 years now and has been maintained by the BMW (under warranty & extended warranty). I do all my repairs and have been since I was in my early 20s. The problem now is that I know very little about BMW's, I have owned several Nissan's, Acura's, Toyota's and GM trucks. Attached Images Last edited by 335ivin; 12-05-2018 at 02:26 PM..
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12-05-2018, 10:53 AM	#2
CoffeeBean Lieutenant 226 Rep 553 Posts Drives: 640i M-Sport GC Join Date: Aug 2012 Location: AL iTrader: (2)	Likely oil pan gasket. Check up above there where the gasket is. If it's not leaking much then let it be as it's not a cheap or easy job.
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12-05-2018, 11:55 AM	#3
TheMidnightNarwhal Major General 2651 Rep 6,281 Posts Drives: 11' 335is DCT Join Date: Jun 2015 Location: Gatineau, Quebec iTrader: (0)	Yeah start from above. If it's not valve cover gasket or oil filter housing area leaks I wouldn't worry about it until it's leaking a lot. Make sure your belt is clean and dry. Sometimes the oil filter housing can leak only on the backside. This is what happened to me and the way I dwelve into it was my coolant had just little amounts of sludge and oily film.
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12-05-2018, 01:30 PM	#4
srey Lieutenant 220 Rep 418 Posts Drives: 2007 E90 335i 6mt Join Date: Jun 2017 Location: Idaho iTrader: (0)	It could be the oil pan gasket or the valve cover gasket. I wouldn't rule out your rear main seal either, but it's likely one of the other two. The OPG isn't difficult, per se, but it is time consuming. You would need to put the car on jack stands, hold up the engine with a support bar, drop the subframe, unbolting the steering rack as well, and then drop the oil pan. Some people say it's not worth it to DIY, but when I did it the car was not my only vehicle, so I took a few days and did it in chunks. It sure was nice to only be out tens of dollars and some of my time verses thousands of dollars to have a shop do it.
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12-05-2018, 02:15 PM	#5
Efthreeoh General 17199 Rep 18,692 Posts Drives: The E90 + Z4 Coupe & Z3 R'ster Join Date: May 2012 Location: Virginia iTrader: (0)	You have an oil leak?
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12-06-2018, 06:51 AM	#8
335ivin Private First Class 20 Rep 106 Posts Drives: 335i Sedan Join Date: Jan 2015 Location: Pearland, Texas iTrader: (0)	Update Last night after work I started looking into the mysterious leak, after looking at it closer I saw the inlet piping by the rear turbo soaked with oil. At first I thought it was coming from the oil supply line but saw that those areas were bone dry. I followed the inlet piping up and saw that it ties into the PVC valve. I removed the plastic that's on top of the valve and saw wet oil spots all around the PVC valve. With that said are these cars known for leaking oil there too? I'm going to install a catch can to see if this keep the oil out. I've attached a picture of the inlet piping to the rear turbo, how is that pipe clamped down? I don't see a clamp. By the way, after doing all that investigation I realized the first pictures I posted are from the motor mount. lol Attached Images Last edited by 335ivin; 12-06-2018 at 12:59 PM..
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