Oil Catch Can install on 2017 E300
Thread Starter
Junior Member
Joined: Mar 2010
Posts: 33
Likes: 1
From: Middle of the Pacific
2017 E300
Oil Catch Can install on 2017 E300
I recently did a Racechip install on my E300, and while I had the inter cooler and the guts below it removed, I thought, maybe I should add a catch can. I searched the web, and did not find anything related to catch can install on the M274 engine.
So, here is how I installed mine.
Just an FYI, I did not plan on taking any pics of the install, the idea only dawned on me about half way in, and it was dark, so the lighting is not the best(head flashlight). I may not have pictures for every step of the install.
First, the items list:
Catch can
5/8" fittings
https://www.ebay.com/itm/165737094675
Hoses
https://www.fcpeuro.com/products/mer...ast-1120180482
Elbow 3/4" PEX fittings
https://www.homedepot.com/p/3-4-in-B...3434/301541105
The 5/8" fittings for the can are NOT necessary, as the catch can comes with 13mm and 15mm(which I did not know at the time of ordering), however, I wanted to have the least flow restriction possible, and those 5/8"(16mm) fittings were the largest one I could find in the M16x1.5 thread. Again, NOT needed as they are quite expensive, and the included 15mm ones should work just fine.
First thing is to find a suitable mounting location for the catch can. In my case, the left frame rail was the best and most accessible location. There are 2 holes on the frame suitable to mount the included bracket. There is an AC line right next it, so to minimize the chance of line damage due to rubbing, I slipped some 1/4" wire loom over it.
With the can mounted, next things was to find a suitable place in the PVC line to cut and install the elbows. The place I chose was the smoother spot on the line, just above where the upper radiator hose connects to the thermostat housing. I used a new razor blade to make a clean, straight cut into the line.
The elbows, out of the box, would not fit into the open line. I had to file down the ribs on one of the ends of each elbow, essentially make it almost smooth, to be able to press it into the plastic line. I lightly greased the filed down ends of the elbows and pushed them into plastic line, turning them back and forth while pushing them in. The end result was a tight fit, but they can still be rotated to align with the hoses that were gonna be connected to them.
Next, it was time to connect the catch can with the open PCV line. The breather hoses I used are the M112 and M113 engine stock full load breathers, and they fit perfectly, even the shape of the pipes was spot on.
After a mock up fitment, I had to cut them down to length. They slipped right onto the fittings on both sides, snug on the can side, but a bit loose on the PCV side, so I used zip ties(did not have right size clamps on hand atm)
Important, the outlet line on the catch can goes towards the intake pipe(left hand side from you), and inlet line goes to the engine(right hand side from you). Make sure all the connections are tight, and the catch can is sealed, you do not want any air/vacuum leaks.
And that is what the end result looks like. The engine idles smoothly as it did, no engine light.
Something to mention, the catch can that I chose, had the inlet and outlet mislabeled according to amazon reviews. The can that I received, had the markings partially corrected, what I mean is, the wording was correct, but the arrows were wrong. If you do choose to go with this particular catch can, be mindful of this, and remember, the built in brass filter goes on the outlet side(the line going to the intake pipe)
Racechip hiding in there
The can has been on for about a week now, and I have yet to put any significant miles on it. I will keep the thread updated. This is my weekend car, I barely drive it. It's a 2017 with 18K miles...
So, here is how I installed mine.
Just an FYI, I did not plan on taking any pics of the install, the idea only dawned on me about half way in, and it was dark, so the lighting is not the best(head flashlight). I may not have pictures for every step of the install.
First, the items list:
Catch can
5/8" fittings
https://www.ebay.com/itm/165737094675
Hoses
https://www.fcpeuro.com/products/mer...ast-1120180482
Elbow 3/4" PEX fittings
https://www.homedepot.com/p/3-4-in-B...3434/301541105
The 5/8" fittings for the can are NOT necessary, as the catch can comes with 13mm and 15mm(which I did not know at the time of ordering), however, I wanted to have the least flow restriction possible, and those 5/8"(16mm) fittings were the largest one I could find in the M16x1.5 thread. Again, NOT needed as they are quite expensive, and the included 15mm ones should work just fine.
First thing is to find a suitable mounting location for the catch can. In my case, the left frame rail was the best and most accessible location. There are 2 holes on the frame suitable to mount the included bracket. There is an AC line right next it, so to minimize the chance of line damage due to rubbing, I slipped some 1/4" wire loom over it.
With the can mounted, next things was to find a suitable place in the PVC line to cut and install the elbows. The place I chose was the smoother spot on the line, just above where the upper radiator hose connects to the thermostat housing. I used a new razor blade to make a clean, straight cut into the line.
The elbows, out of the box, would not fit into the open line. I had to file down the ribs on one of the ends of each elbow, essentially make it almost smooth, to be able to press it into the plastic line. I lightly greased the filed down ends of the elbows and pushed them into plastic line, turning them back and forth while pushing them in. The end result was a tight fit, but they can still be rotated to align with the hoses that were gonna be connected to them.
Next, it was time to connect the catch can with the open PCV line. The breather hoses I used are the M112 and M113 engine stock full load breathers, and they fit perfectly, even the shape of the pipes was spot on.
After a mock up fitment, I had to cut them down to length. They slipped right onto the fittings on both sides, snug on the can side, but a bit loose on the PCV side, so I used zip ties(did not have right size clamps on hand atm)
Important, the outlet line on the catch can goes towards the intake pipe(left hand side from you), and inlet line goes to the engine(right hand side from you). Make sure all the connections are tight, and the catch can is sealed, you do not want any air/vacuum leaks.
And that is what the end result looks like. The engine idles smoothly as it did, no engine light.
Something to mention, the catch can that I chose, had the inlet and outlet mislabeled according to amazon reviews. The can that I received, had the markings partially corrected, what I mean is, the wording was correct, but the arrows were wrong. If you do choose to go with this particular catch can, be mindful of this, and remember, the built in brass filter goes on the outlet side(the line going to the intake pipe)
Racechip hiding in there
The can has been on for about a week now, and I have yet to put any significant miles on it. I will keep the thread updated. This is my weekend car, I barely drive it. It's a 2017 with 18K miles...
Last edited by nenad16; Dec 15, 2022 at 02:11 AM.
Thread Starter
Junior Member
Joined: Mar 2010
Posts: 33
Likes: 1
From: Middle of the Pacific
2017 E300
I chose to tap into the corrugated plastic pipe, one visible just under the inter cooler and above the upper radiator hose.
The catch can works well, I get about 3/4oz of oil every oil change (3k miles interval). It may not seem like much, but that's 3/4oz of oil kept out of the intake and less carbon deposits on the intake valves in the long run.
I have since done a few performance upgrades, such as cold air intake and upgraded all aluminum inter cooler.
The catch can works well, I get about 3/4oz of oil every oil change (3k miles interval). It may not seem like much, but that's 3/4oz of oil kept out of the intake and less carbon deposits on the intake valves in the long run.
I have since done a few performance upgrades, such as cold air intake and upgraded all aluminum inter cooler.
