[RobertoTaylor]

So I had my intake valves cleaned a week ago (100K on motor), and I ordered a BMS Oil Catch Can to help prevent this common problem with our motors.

Well, someone on Facebook said that the BMS oil catch can doesn't really help much, because 98% of the build up comes from the off-boost system which is right above each intake valve. So basically, I'm hearing that the BMS oil catch can only prevents oil vapors from the on-boost system, and not the off-boost system.

If this is the case, should I just send it back for a refund before I even bother installing it?

Any info or input will be greatly appreciated.

[fazman]

Originally Posted by RobertoTaylor

So I had my intake valves cleaned a week ago (100K on motor), and I ordered a BMS Oil Catch Can to help prevent this common problem with our motors.

Well, someone on Facebook said that the BMS oil catch can doesn't really help much, because 98% of the build up comes from the off-boost system which is right above each intake valve. So basically, I'm hearing that the BMS oil catch can only prevents oil vapors from the on-boost system, and not the off-boost system.

If this is the case, should I just send it back for a refund before I even bother installing it?

Any info or input will be greatly appreciated.

I've been running turbo cars for well over 20 years now... and all of them benefit from having a Oil Catch Can (including my n54). Is it a silver bullet to cure carbon build up... NO. Does it help... YES. Can it be used as an indicator to see if your PCV system is working well DEFINITELY!

Since you are already making the effort to install the OCC I would also recommend the following since you are at the 100k mark:

1) RB PCV
2) RB PCV Cap
3) RB PCV Hose

If you couple those 3 items installed at the same time as the BMS OCC... your labor should be zero for the 3 items I listed above since the cost of labor to install the BMS OCC is the same work as the PCV items I listed above. It would have been well timed to do it during the carbon blast since most of the tear down was done already. Also with carbon blasting... you should also consider doing an ER CP install at the same time as the carbon blast... since the labor cost to install will be zero as part of the normal tear down.

Since you have a RWD 2007 n54... have you had your belt and tensioner/pully replaced yet? This is a common failure point where the belt rubs the subframe and then shreds apart and then gets sucked in THRU the front main seal into the motor and grenades the motor Get it fixed asap if it wasn't done already.

[shadow191]

On some cars, it catches a lot, on others, nothing. I have one and there was maybe a teaspoon of oil after 5K miles. But I've seen some that were overflowing.

RB now makes a version of the catch can for the other side of your system so it works when you're not boosting which is most of the time. I'm likely going to get that pretty soon.

[fazman]

Originally Posted by shadow191

On some cars, it catches a lot, on others, nothing. I have one and there was maybe a teaspoon of oil after 5K miles. But I've seen some that were overflowing.

RB now makes a version of the catch can for the other side of your system so it works when you're not boosting which is most of the time. I'm likely going to get that pretty soon.

I'm lucky... my PCV system has been really good. I only get a tiny amount of oil in the BMS OCC every 20k miles.

[Conti.]

Originally Posted by shadow191

On some cars, it catches a lot, on others, nothing. I have one and there was maybe a teaspoon of oil after 5K miles. But I've seen some that were overflowing.

RB now makes a version of the catch can for the other side of your system so it works when you're not boosting which is most of the time. I'm likely going to get that pretty soon.

you have a link to robs system? i didn't see it on their site

[shadow191]

I think it's still early in production phase. There's a big post on the n54tech forums, just search for RB External PCV.

Originally Posted by Conti.

you have a link to robs system? i didn't see it on their site

[RobertoTaylor]

Originally Posted by fazman

I've been running turbo cars for well over 20 years now... and all of them benefit from having a Oil Catch Can (including my n54). Is it a silver bullet to cure carbon build up... NO. Does it help... YES. Can it be used as an indicator to see if your PCV system is working well DEFINITELY!

Since you are already making the effort to install the OCC I would also recommend the following since you are at the 100k mark:

1) RB PCV
2) RB PCV Cap
3) RB PCV Hose

If you couple those 3 items installed at the same time as the BMS OCC... your labor should be zero for the 3 items I listed above since the cost of labor to install the BMS OCC is the same work as the PCV items I listed above. It would have been well timed to do it during the carbon blast since most of the tear down was done already. Also with carbon blasting... you should also consider doing an ER CP install at the same time as the carbon blast... since the labor cost to install will be zero as part of the normal tear down.

Since you have a RWD 2007 n54... have you had your belt and tensioner/pully replaced yet? This is a common failure point where the belt rubs the subframe and then shreds apart and then gets sucked in THRU the front main seal into the motor and grenades the motor Get it fixed asap if it wasn't done already.

Thanks for all the info. Looks like I'll be installing it then, and looking into replacing those other parts.

[fazman]

Originally Posted by RobertoTaylor

Thanks for all the info. Looks like I'll be installing it then, and looking into replacing those other parts.

Good call.. but don't slack on that tensioner/pully/belt... I'm at 108k miles and I've been slacking (I'm an XI so I don't suffer from the common issue like the RWD guys actually do).

[mike@x-ph.com]

OCC does wonders on some cars, and not great on others.
Either way definitely worth it given the price it is being offered at

[ferocity02]

As mentioned the BMS OCC is for the boost-side; air only passes through it when you in boost which for most of us is a very small portion of the time. If you have a heavy right foot then it might help. I had mine for 12k miles and it caught maybe 1/4 tsp of oil.

The other 98% of the time the vacuum-side PCV system is in use. This system is build into the valve cover which dumps the air and oil right into the intake ports and onto the intake valves; this is primary cause of carbon build up.

I bypassed the stock vacuum-side PCV system and ran an inline catch can. In 70 miles it's caught about twice what the BMS can caught on the boost-side in 12,000 miles.

http://www.e90post.com/forums/showthread.php?t=1231974

[=C=]

Originally Posted by RobertoTaylor

Thanks for all the info. Looks like I'll be installing it then, and looking into replacing those other parts.

The PCV Valve is all you really need. The Cap is not necessary and the rest you can re-use.

I installed the BMS OCC tonight

Will see how it goes in the next 5k kms

I couldn't believe how much oil was in the PCV hose...

[b1mmr]

Originally Posted by mike@x-ph.com

OCC does wonders on some cars, and not great on others.
Either way definitely worth it given the price it is being offered at

At 180 bucks... How is that remotely great lol

[Cory S]

The build up of combustion carbon on the intake valve stems/ports, is not so much from incoming air, but combustion gases blowing up through the valves at specific valve timing events.

[Will maddox]

Can the pcv system just be blocked off altogether on these engines??