[richie_s]

I've been wanting to give Seafoam a try after using Chevron Techron Fuel System cleaner and doing an "italian tuneup" the day before my oil change. These two techniques completely eliminated the subtle rough idle issue I occasionally experienced and made the car run smoother. The revs build up with less hesitation especially in the low range.

I'm guessing I had a lot of carbon buildup in the engine due to my short daily commute and the fact that I rarely ever rev it above 3k RPM

Since the 335i is direct injection, would it be wise to just dump Seafoam into the gas tank or try a different technique?
SHould I even try Seafoam in the first place?
I have 27,000 miles on the car.

[Orion4]

If you've been using Techron, I don't see much additional benefit by using the Seaform. Techron should be doing a good job of keep the injectors clean along with the combustion chambers. Since, as you mentioned, this is a DI engine neither will do anything for the carbon build up on the valve seats, stems or mating surfaces since the fuel never touches these except for the combustion face of the valves. Walnut blasting address that issue. Just my thoughts.

[Bartman619]

Seafoam will probably not do anything since the N55 is DI/the fuel injected sprays the fuel right in the combustion chamber and not behind the valves. You probably want to take it in for walnut blasting or try running your car in the fwy more often at high speeds so the hot engine may help break down the carbon. FYI, you shouldn't really need to use Seafoam anyway since you're already using a Top Tier fuel from Chevron. If you do use it, be sure you change your oil, because all the crud that Seafoam does clean will end up in the oil. Hope this helps.

[Fast400]

Don't do it. It will be useless. Fuel doesn't touch the valves. Walnut method is the best.

[richie_s]

Originally Posted by Bartman619

Seafoam will probably not do anything since the N55 is DI/the fuel injected sprays the fuel right in the combustion chamber and not behind the valves. You probably want to take it in for walnut blasting or try running your car in the fwy more often at high speeds so the hot engine may help break down the carbon. FYI, you shouldn't really need to use Seafoam anyway since you're already using a Top Tier fuel from Chevron. If you do use it, be sure you change your oil, because all the crud that Seafoam does clean will end up in the oil. Hope this helps.

I used a non-top tier gas for 10,000 + miles and I rarely go above 3,000 RPM. The car runs fine but occasionally gets an awkward idle. So far, I have 27,000 miles on it with the last 17,000 being on top tier gas. Still makes me uncomfortable to think about what could be under the hood because I know that DI engines get nasty real quick.
I guess I'll just find a reputable third party to walnut blast the intake valves & start stretching out the car's legs more often

[1987E30M3]

Open the car up more brother, the engine was made to rev . You most likely have not broken in your engine correctly, which hinders performance. Also why did you even get a 335 if you didnt want the extra power brother, you have it and should use it more often.

Originally Posted by richie_s

I used a non-top tier gas for 10,000 + miles and I rarely go above 3,000 RPM. The car runs fine but occasionally gets an awkward idle. So far, I have 27,000 miles on it with the last 17,000 being on top tier gas. Still makes me uncomfortable to think about what could be under the hood because I know that DI engines get nasty real quick.
I guess I'll just find a reputable third party to walnut blast the intake valves & start stretching out the car's legs more often

[richie_s]

Originally Posted by 1987E30M3

Open the car up more brother, the engine was made to rev . You most likely have not broken in your engine correctly, which hinders performance. Also why did you even get a 335 if you didnt want the extra power brother, you have it and should use it more often.

No clue, man.. I like the look of the exhaust pipes on the 335i better than the 328

Lately I've been opening the car up a lot more and I can tell that the low-end torque is smoother but the car still gets awkward idles every now and then

[F30lolz]

Agreed with everyone on the walnut blasting. Has anyone gotten it done at their local $tealer? A dealer near my house was offering $450 (4 and 6 cyl models). What's the ballpark figure from indy shops?

[Damon44]

Originally Posted by 1987E30M3

Open the car up more brother, the engine was made to rev . You most likely have not broken in your engine correctly, which hinders performance. Also why did you even get a 335 if you didnt want the extra power brother, you have it and should use it more often.

I only use top tier gasoline anyway. Gas is cheap. However I have too many short errands so at least once a week I get on the highway at 80 mph for about 30 min to heat things up. Try to rev past 5000 on entry ramp if I can.
The Techron is cheaper than sea foam and my 435 runs smooth as a baby's butt.
Short trips kill your engine.