[timothy2001]

Have seen two schools of thought on this. I purchased a JB4 over Cobb using a poll and I expect I know what this outcome will be too.

Thanks for the input.

[Dhillon92]

I don't have one, most people who have actually used them say there isn't a need, I guess you can't know until you try it. I've taken off my charge pipe a few times over the past 40k km, never more than a slight film of oil, if that.

However I do plan to install one if I do find it an issue, maybe I'll wait and see how my intake valves are for my first blast.

[Welcome to NBA Jam]

I did it. It was cheap and the hardest part was cutting the hoses to size. Figure it wouldn't hurt.

[EB89]

Originally Posted by Welcome to NBA Jam

I did it. It was cheap and the hardest part was cutting the hoses to size. Figure it wouldn't hurt.

I thought the hose cutting was easy.

Detach the old hoses, screw in place the OCC.

Plug the hosees into the car and then lay the other ends over the OCC, make a mark, cut then push it on.

Cutting the engine cover was a little more difficult.

[Dark_Knight_335]

N55 I would pass.

N54- don't drive without one.

[Dhillon92]

Originally Posted by Dark_Knight_335

N55 I would pass.

N54- don't drive without one.

Didn't you buy one and sell one and buy another one again? LOL

[Cory S]

The built in PCV/oil separation system on the N55 requires no extra aftermarket catch can/separators.

[Johnny Boost]

I was told by a BMW tech that it is not necessary to buy the catch can for the n55.

[Joey911]

To all of you who doesn't need one.

Not the best picture of the intake manifold but.. It's not bad at all at 48k miles, boosted since between 25 to 30k miles.

PS: photos failed uploading through the app... Will do it when I'm on computer

[Dark_Knight_335]

Originally Posted by Dhillon92

Didn't you buy one and sell one and buy another one again? LOL

Yup, cuz I'm a dummy. Twice confirmed there was virtually nada in the can.

[Welcome to NBA Jam]

Originally Posted by EB89

I thought the hose cutting was easy.

I had the wrong cutting tool All I had was a pair of crappy sidecutters that didn't open wide enough. I don't recommend using those.

That engine cover took ages to cut. The instructions are fairly conservative on how much to grind away.

[olivojoe]

I don't feel comfortable telling someone whether or not to use one, but FWIW my experience in the N55 after over a year of running with one, FBO with a pro tune, not a single drop of oil.

Like everyone has said, BMW did a pretty good job of sorting out the oil issue by re-engineering the PCV system. I just put one on mine at nearly day one out of paranoia, figured it cant hurt.

[EB89]

Originally Posted by Welcome to NBA Jam

I had the wrong cutting tool All I had was a pair of crappy sidecutters that didn't open wide enough. I don't recommend using those.

That engine cover took ages to cut. The instructions are fairly conservative on how much to grind away.

Haha yeah the right tools always help.

I used some massive tin snips for the hose, went through like a hot knife cutting butter haha.

The engine cover I hacked at it with a serrated knife then sanded down the edges to make it look a bit neater and so it doesn't cut the hoses.

I did that around 6 months ago, i should really check the can to see whats inside.

[loesch]

I get a lot of gross yellowish condensation in mine. Not sure if it's of any benefit though.

[f30luxline]

Originally Posted by loesch

I get a lot of gross yellowish condensation in mine. Not sure if it's of any benefit though.

I get a similar fluid in mine. I think for the most part it is condensation but it smells somewhat like gas. This is prob from the motor venting through it.

[mike@x-ph.com]

You wont know whether you need one or not before installing it ... At the current price it is being offered for i would get one

[timothy2001]

Originally Posted by mike@x-ph.com

You wont know whether you need one or not before installing it ... At the current price it is being offered for i would get one

That makes perfect sense to me. These engines seem to have their own individual personalities. Almost.

[Dhillon92]

You got me considering one pretty soon, this poll is growing interestingly.

[WiL335i]

I also bought one but after over 10,000 miles, I looked in the can and barely anything in it. I also took mine off.

[jwalker87]

I have both an N54 and N55, both roughly FBO and with BMS OCCs. Strangely, the N54 never has any oil in it, while the N55 has around 1/4" to 1/2" at oil change time (7500 miles). Meh, I guess every engine's different.

[vespa]

Turbo engines use 2 separate crankcase ventilation paths: one when boost is positive (accelerating), and the other when boost is negative (cruising).

• Commercial N55 catch cans install on the positive boost path only.
• The negative boost path is fully integrated into the valve cover and connects to the intake tract just upstream of the rearmost valve (shown at right). It is not practical to intercept this path with a catch can.

The attached photo (stolen from Weehe's N54tech post) shows the first inspection of his N55 at 80K miles without a catch can. This particular engine had a bad PCV regulator and was drawing excessive vapors for at least 5K miles so his carbon buildup should be worse than normal but what you can see here is:

• Carbon buildup is highly biased toward the rear valve, where catch cans have little effect.
• Carbon buildup on the front valve is tolerable at 80K miles with no catch can.