[augerpro]

I assume the N55 has a PCV, if so anyone use a catch can on this motor? I think Excel makes some nice ones though I haven't used them.

[augerpro]

So no one sees any use in a catch to help prevent intake valve carbon buildup or possibly pre-ignition (an issue in some Chryslers)?

[configt]

I have been wondering the same. I also wonder if it would cause warranty issue.

[ketema]

Bump. I'd like to know if it would help.

[augerpro]

Yeah I'm not sure why there isn't much interest. Only one thread in 3er forum. DI, turbo, and a known history of dirty intake valves make it seem like no-brainer to me.

[Ramathorn]

I had the same question and contacted Burger Motorsports about catch can availability for the M235 and got the following response:

"We don't have plans for F series OCC.
From our initial testing F series doesn't need it."

[2msport]

Originally Posted by Ramathorn

I had the same question and contacted Burger Motorsports about catch can availability for the M235 and got the following response:

We don't have plans for F series OCC.
From our initial testing F series doesn't need it.

Man I hope that's true after reading this.

http://www.edmunds.com/autoobserver-...-adopters.html

This guy's RS 4 lost 20hp in 10,000 miles. It was a 2008 so it was early for DI cars, but still. In contrast Ford DI engine testing showed it only lost 1hp after 160,000 miles. Apparently they "determined the proper injection-timing calibration to help eliminate the carbon deposits". I hope BMW has figured that out as well, as I've read earlier models have had hp loss after about 40k-50k miles and needed walnut blasting to reverse the loss.

I have also been curious about the oil catch can but I'm optimistic they've made strides in eliminating the issue. Hearing that from Burger gives me a warm fuzzy.

[Fast400]

Why not alky injection instead? Clean valves + more power

[2msport]

Originally Posted by Fast400

Why not alky injection instead? Clean valves + more power

Alky as in alcohol? How does that work?

[MrBucket]

Originally Posted by 2msport

Man I hope that's true after reading this.

http://www.edmunds.com/autoobserver-...-adopters.html

This guy's RS 4 lost 20hp in 10,000 miles. It was a 2008 so it was early for DI cars, but still. In contrast Ford DI engine testing showed it only lost 1hp after 160,000 miles. Apparently they "determined the proper injection-timing calibration to help eliminate the carbon deposits". I hope BMW has figured that out as well, as I've read earlier models have had hp loss after about 40k-50k miles and needed walnut blasting to reverse the loss.

I have also been curious about the oil catch can but I'm optimistic they've made strides in eliminating the issue. Hearing that from Burger gives me a warm fuzzy.

My father has a 2007 RS4 and it definitely gets a lot of carbon buildup on the valves and intake ports. I've followed the issue closely and nothing has been shown to help with the buildup. My friend had a B7 RS4 and he had a catch can installed and it didn't do a thing to help with the carbon buildup. The only thing that can be done is just to have the intake pulled and have the valves and ports manually cleaned. Also 20hp is a low figure for power loss on the BNS V8 in the RS4. I've heard of people gaining back 40+ whp after a cleaning. He got the cleaning done at around 22k miles two years ago and having driven it before and after the cleaning, I have to say he probably was down more than 20hp at a minimum from that time.

I think Toyota figured out the right thing to do by putting an extra injector in the intake just to have a little fuel wash over the valves.

[MrBucket]

Originally Posted by 2msport

Alky as in alcohol? How does that work?

Methanol

[2msport]

Originally Posted by MrBucket

Methanol

Just curious. Is that proven to combat carbon build up?

[MrBucket]

Originally Posted by 2msport

Just curious. Is that proven to combat carbon build up?

Since its indirectly injected it mixes with the air and can wash over the valves and intake ports.