No Oil in the catch can.

NoGuru

Captain
Jan 9, 2018
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I added an ebay catch can this past fall just before new turbos went on. I only started driving the car a little recently and noticed I am not getting any oil in the catch can.
The route is from the valve cover or PCV location to the can, and then to the intake tube. Is there a way this could be wrong or something?

I ask because I just took off my intake manifold and seemed like there was oil, around the intake near the valve ports.
 

matreyia

Major
Apr 19, 2017
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As others have said, the high side catches next to nothing, the low side empty every 1000km/mile. Can't comment on the BMS style eBay catch cans, but I've been using the eBay mishimoto style baffled cans on the low side (RB kit w/ plugged head port) with no problems.

High side captures less than low side but not as you would describe. Let me know if you want to see a video of how much oil can be caught by a proper functioning high side can. I can post it here.
 

matreyia

Major
Apr 19, 2017
1,780
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335i e93
I added an ebay catch can this past fall just before new turbos went on. I only started driving the car a little recently and noticed I am not getting any oil in the catch can.
The route is from the valve cover or PCV location to the can, and then to the intake tube. Is there a way this could be wrong or something?

I ask because I just took off my intake manifold and seemed like there was oil, around the intake near the valve ports.

High side takes weeks to months for oil to collect. Low side can be seen in one tank of gas.
 
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ansch

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Sep 23, 2018
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High side takes weeks to months for oil to collect. Low side can be seen in one tank of gas.

I was exaggerating 😁, your description is more accurate. I'd clean out the high side every six to nine months (genuine BMS can and stock flapper if that makes a difference) when I do a general intake clean. The low side I'd empty a couple of times in between oil change. (every 3000km because ethanol 🤷‍♂️)
 

KClemente

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Nov 26, 2019
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E90 335i
I added an ebay catch can this past fall just before new turbos went on. I only started driving the car a little recently and noticed I am not getting any oil in the catch can.
The route is from the valve cover or PCV location to the can, and then to the intake tube. Is there a way this could be wrong or something?

I ask because I just took off my intake manifold and seemed like there was oil, around the intake near the valve ports.
If you bought the ebay catch can, I guarantee you that the baffles are on the wrong side. It may or may not matter but it isn't how it was designed to be placed. Its easy to swap it over to the other side. 2 hex screws and the baffle is out.

My ebay high side (with proper baffle location) barely catches anything but it does work somewhat.
 

matreyia

Major
Apr 19, 2017
1,780
711
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335i e93
If you bought the ebay catch can, I guarantee you that the baffles are on the wrong side. It may or may not matter but it isn't how it was designed to be placed. Its easy to swap it over to the other side. 2 hex screws and the baffle is out.

My ebay high side (with proper baffle location) barely catches anything but it does work somewhat.

What I did was compared the ebay can with bms and used bms as a guide to connect hoses. Crazy oil caught.
 
Last edited:

xargentum

New Member
Feb 10, 2023
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BMW E93 335i
I think the baffle was on the wrong side. The hose from the PCV to the in had the baffle and the out or hose to me inlet has no baffle. I reversed it so I will test as soon as I put my port injection back in and will give an update.
Sorry for old thread. But can maybe some one clear it out: the baffle - should be at the IN of catch can, or at the OUT?

Because my catch can is empty too.