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Old 09-12-2019, 01:32 PM
Flying Ace Flying Ace is offline
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Location: San Francisco, California
Join Date: Jan 2015
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Mein Auto: M6 GC ZCP; '12 X5 Diesel
35d oil leak diagnostic

I've had a minor oil leak on my 35d for about a year now. I lose about half a bottle of oil every 3 months. My local BMW dealership started offering a free "visual" inspection. I took the car in for an inspection of the leak and they came back with this "visual diagnostic":

1. Oil leak at turbo charge pipe PN 11617799873

2. Oil leak at oil pan area. Possible leak from oil level sensor gasket PN 12617607910 and PN 07119963151

Now I know there's always a good chance this is a misdiagnosis as this was simply a visual inspection. They pull the bottom cover off, maybe feel around the area of the leak and then estimate where the location of the leaks are.


Issue 1. I think this is pretty straight forward. I'm going to buy a new pipe and the two seals: PN 13718596850 PN 11617796622

Do you think this will likely fix the leak related to the charge pipe? It appears this an intake air pipe to the turbo. How can an air pipe cause an oil leak? I can see the plumbing going to the blow-off-value and the turbine, so it's definitely plumbing for air intake into the turbo. This was the 2nd time they made the same diagnostic. Is this a misdiagnosis and is there anything else I should consider while I'm in the area?

Issue 2. This is the first time this diagnostic came up. I changed my oil 2 weeks ago, and I noticed at the point of the oil pan drain plug, a small flow/drip of oil was pooling on the plug's head. I double checked the drain plug to ensure it was threaded on correctly, and I used the supplied o-ring gasket and torqued it down to spec. So I'm sure the leak is not coming from the plug.

So I'm thinking of buying all the bolt, gasket and nut related to the sensor in addition to the sensor itself. #2, #18, #19.

Do you think it's overkill to buy the sensor, as I should replace the gasket first? If i pull the sensor out, does that mean the entire oil pan will drain, i.e. I'm effectively changing the oil?
Also, BMW identified gasket -151 as part of the diagnostic. On the diagram, I cannot tell where this gasket goes and it's not apparently related to the sensor's mounting position. Where does this gasket go, how many are there?

thanks in advance!
2014 F06 M6 (oil rig fire)
2012 E70 X5 diesel (oil burner)
2008 E90 M3 (oil distillates guzzler- Retired)
2013 bicycle (oily chain)

Last edited by Flying Ace; 09-12-2019 at 01:57 PM.
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