[olivojoe]

I am new to this site, and I have done a bit of digging and I have not come accross anything where this point was brouhgt up.

I live in central Florida and I just purchased a 2011 335i with roughly 23,000 miles.

I would like to know opinions/possible experiences about the possibility of polishing the intake ports in hopes to prevent the inherent carbon buildup that comes along with these DI engines. The logic behind my thinking is that if there is less surface area for the carbon to adhere to initially, it may not build up as bad.

I am not interested in discussing potential power gains/losses involved with porting and polishing. I just wanted to bounce the idea off the people on this site that have more knowledge on this issue than myself.

[2jzn54]

won't prevent carbon buildup at all.. you'll want to walnut blast or hand clean the ports generally whenever the buildup happens

[olivojoe]

I spoke with Fields BMW in Winter park and my car is still covered under factory warranty, and the guy in the service department said the walnut blasting was covered under warranty. I am just looking at options for moving forward while out of warranty.

Also, many people swear by the oil catch cans, but everyone's opinions on them are so divided, and I cannot find any hard evidence anywhere online or via talking to mechanics that it does anything to prevent the carbon buildup.

[Delta0311]

Carbon build up is not really much of an issues in the N55 as it is in the N54. A friend of mine checked his intake valves at around 45k miles and they where perfectly clean. I was talking to him last week and one of his co-workers went to get a walnut blast done with a N55 that has close to 65k miles. The tech told him to hold off because there was hardly any build up on the valves.

At 23k miles the car is just stretching its legs. Walnut blasting is not something you should be worrying about.

[shadow191]

From what I've read, catch can doesn't prevent carbon buildup. The intake valves see oil from other passages not impacted by the OCC. Catch can will prevent oil from getting into your intake pipes and IC, but not much for buildup.

[olivojoe]

Cool, thanks for the info.

Delta0311, was your friends car seeing those conditions as a stock vehicle or was he running with modifications like a tune, intake, etc.?

So in everyones opinion for the N55, would it be worth me purchasing an extended warranty for my vehicle, seeing as how the dealership claims that the walnut blasting is covered under warranty? I've never priced out the walnut blasting anywhere so I dont know what the breakeven would be on a warranty. Regardless, if it only needs to be done at every 70-80k or more, it may not be worth the $3,000 price tag for the warranty on it.

[trixdout]

Originally Posted by olivojoe

Cool, thanks for the info.

Delta0311, was your friends car seeing those conditions as a stock vehicle or was he running with modifications like a tune, intake, etc.?

So in everyones opinion for the N55, would it be worth me purchasing an extended warranty for my vehicle, seeing as how the dealership claims that the walnut blasting is covered under warranty? I've never priced out the walnut blasting anywhere so I dont know what the breakeven would be on a warranty. Regardless, if it only needs to be done at every 70-80k or more, it may not be worth the $3,000 price tag for the warranty on it.

the walnut blasting will not solely warrant getting the warranty, but the water pump or any other "electrical" issue that may come up will. Water pump alone is worth $2k if done at the dealer.

[Delta0311]

Originally Posted by olivojoe

Cool, thanks for the info.

Delta0311, was your friends car seeing those conditions as a stock vehicle or was he running with modifications like a tune, intake, etc.?

So in everyones opinion for the N55, would it be worth me purchasing an extended warranty for my vehicle, seeing as how the dealership claims that the walnut blasting is covered under warranty? I've never priced out the walnut blasting anywhere so I dont know what the breakeven would be on a warranty. Regardless, if it only needs to be done at every 70-80k or more, it may not be worth the $3,000 price tag for the warranty on it.

No mods except for rims. Don't know about his co-workers car though.

[2jzn54]

occ will catch some, but gunked up ports are inevitable.. If you get walnut blasting done right now you'll probably be fine for quite a while every 50k is probably a good idea.. if you had the time/care/tools i'd say do it more frequently because it will build up fast