Author Topic: Crankase pushing out too much oil.  (Read 3687 times)

aguyther

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Crankase pushing out too much oil.
« on: February 26, 2015, 01:23:55 PM »
You all might have seen my previous posts about my issues that include quite a bit of oil burning. I am seeing a lot of oil in the intake boot/throttle body, and my ICV seems to be getting gummed up very quickly. Since the car does not actually have a pcv valve, just a vent hose; what do you think could be causing so much oil to be vented through? I recently compression and block tested my car, and both tests came back fine.
1991 318is Slicktop in Sterling Silver

DesktopDave

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Re: Crankase pushing out too much oil.
« Reply #1 on: February 27, 2015, 09:33:34 PM »
I was considering a catch can for mine to keep the intake a little cleaner. I saw an article where someone cleverly used an inline air compressor filter.

I'm not sure why these motors are so oily, but mine leaks a lot too...both internally and externally. I'd figure it's mostly ring blow-by during cold starts, as the motor doesn't burn much oil. Deleting the "mess under the intake" helped a bit but I noted significantly less intake mess after switching to a thinker oil. I'm using synthetic 15w50 currently. My used oil analysis picked up high levels of wear metals with the 5w20 I had been using previously. The thicker oil cleared that up promptly but it wasn't all good. My fuel mileage took a significant hit - I lost 2mpg with the thicker oil.

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aguyther

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Re: Crankase pushing out too much oil.
« Reply #2 on: March 01, 2015, 10:28:15 AM »
I was considering a catch can for mine to keep the intake a little cleaner. I saw an article where someone cleverly used an inline air compressor filter.

I'm not sure why these motors are so oily, but mine leaks a lot too...both internally and externally. I'd figure it's mostly ring blow-by during cold starts, as the motor doesn't burn much oil. Deleting the "mess under the intake" helped a bit but I noted significantly less intake mess after switching to a thinker oil. I'm using synthetic 15w50 currently. My used oil analysis picked up high levels of wear metals with the 5w20 I had been using previously. The thicker oil cleared that up promptly but it wasn't all good. My fuel mileage took a significant hit - I lost 2mpg with the thicker oil.

Any pics on the hose delete? I am definitely interested. I am running 0w-40 for winter, though I am about to switch back to the BMW 5w-30. Kind of sucks seeing as my motor only has 10k on it, but I've tested everything and it reads good compression. I've pretty much declared that it has to be the nature of the motor.
1991 318is Slicktop in Sterling Silver

Nick_318is

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Re: Crankase pushing out too much oil.
« Reply #3 on: March 02, 2015, 01:14:54 PM »
here is the master thread with the mess under the intake.
http://www.m42club.com/forum/index.php?topic=2742.0

This was the best image in that thread:

keflaman

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Re: Crankase pushing out too much oil.
« Reply #4 on: March 02, 2015, 04:31:03 PM »
I don't remember why, but I put a 90 degree plastic fitting near the end of the hose coming out of the valve cover to the bottom of the throttle body. I guess it was to clear another hose or something, but one day I disconnected the fitting to pull the upper manifold and quite a bit of oil spilled out. I noticed there wasn't as much oil in the throat of the throttle body either. In essence, the fitting must have acted like a mini oil catch can. ???