Massive oil leak - source???

Jeffman

Major
Jan 7, 2017
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4B2D8A30-9A4B-48EA-8D29-C061E7694F4D.jpeg
EDIT: See post #7 below. It was a loose bolt on the OCH causing oil to leak into the coolant. :eek:

I saw a huge puddle of oil on the garage floor near the front passenger wheel. So I put the car up on jack stands, took off the wheel, cleaned up the oil (which got all over the suspension, wheel and the under panels, nothing much looking down into the engine). Restarted looked fine cold, but once it warmed up oil started pouring quickly down onto the cover over the steering CV boot - I quickly put that red pail with adsorbent under to catch the flowing oil. It would have easily drained a quart in a minute I’m guessing. Oil also started to run down that black wire near the windshield washer hose.

It’s not leaking at the oil cooler gasket or oil filter housing gasket - I was watching that carefully originally thinking it was the source. And I’m pretty sure it’s not the valve cover gasket. The source of the leak is below the valve cover gasket. Any ideas as to what is the source of the leak?
(Sorry for the sideways picture.)
Thanks.
 
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Jeffman

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Jan 7, 2017
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I found I had a turbo oil line leaking on mine.
Thanks.
Also, I have stock turbos / 66,000 miles / 2008 335xi. Are yours also stock? Can you let me know what was involved in fixing it / how many hours?

I’m trying to decide whether to do it myself or take it to a shop.

(Coincidentally - I had just taken out the BMS oil cooler Tstat and reinstalled the OEM oil Tstat for the winter the day before and drove in a spirited fashion to get the oil temps up to 240F.)
 
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Jeffman

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Jan 7, 2017
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I'll 3rd the oil line.

But because it's a free check, make sure the filters for the vanos solenoids are tight and not leaking; if you haven't dicked with them they shouldn't be, but ...


N54 is virtually same spot
https://www.e90post.com/forums/attachment.php?attachmentid=1162679&stc=1&d=1424710242
Thanks! The picture you sent plus a little more googling makes me very hopeful that it’s the VANOS filters. One must have gotten loose. I saw oil spray on the coolant expansion tank and the dripping below is exactly below where the filters are. I’ll check in the morning and will confirm.
 
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Jeffman

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Jan 7, 2017
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UPDATE - what a dope I am!
When I reinstalled my OEM oil Tstat after the top bolt must have been too loose and oil was pumped under pressure passed the OCH gasket into the coolant side. DOH! I should have realized this immediately as hazy oily stuff was collecting on the top of the radiator expansion top - I should have immediately opened the radiator expansion cap to see the brown gunk in the tank. Pictures below.

Here’s what happened: I had been running the BMS oil Tstat for a few years, even during the winter. This past summer I replaced the OFHG and in doing so mostly stripped the threads in the OFH for the top bolt holding the OCH to the OFH - so it wasn’t properly torqued. But since the BMS Tstat was still in apparently oil pressure within the OCH wasn’t so high to cause a problem. Last weekend I decided to put the OEM Tstat back in. The bolt was not properly torqued, but oil didn’t leak outside of the OCH so I thought I was good to go - WRONG! The oil leak was in the inside, oil pressure pumping oil past the gasket into the coolant side which is only 14.5 psi or so atmospheric. So now I’ll need to do a really thorough job flushing the radiator. Oil change afterwards. Feel free to comment. I’ll cross-post this under my “DOH!” thread. :rolleyes:
https://bmw.spoolstreet.com/threads/doh-im-not-afraid-to-look-like-an-idiot.3522/page-3

I should have realized oily coolant was squirting out from the expansion tank - this is what I saw first:
98D1DDD1-759E-4090-8ABA-FBB5D88D9F38.jpeg


This morning took off the oil cap - should have done this first!
1121EB3A-113E-4ED0-8E39-6EEACB211780.jpeg
 
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iminhell1

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Jun 17, 2018
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Easy enough to fix. Glad it wasn't worse/more involved repair.

Just be sure to helicoil that top bolt so you don't have to redo the repair.