[Jeff@TopGearSolutions]

Originally Posted by Killerfish2012

Jeff, I respect your opinion, but I don't care about 10-15hp at peak, here and there. I measure my vehicles performance by lap times, which have been consistent, thus I've never dyno'ed, and most likely never will.

Thank you. I like to talk facts though. Historically, most people find their intake valves gunked up by as early as 35K. Keyword, historically and most people.

Unless you have pulled the intake manifold off and or scoped the manifold you really don't know.

I tried to decipher how someone who cares about lap times wouldn't care about an extra 10-15 HP? That's 10-15 HP you should normally have if you were running at peak efficiency. Now you are just making your turbo's work harder to potentially meet target.

This thread is really turning into something I didn't want it to be. You are more then welcome to continue to believe your car is running at peak efficiency without getting your intake valves cleaned.

For anyone else I still recommend it 35K-50K. If anything just pulling the intake manifold off would be recommended at that mileage just to take a peek. It's not a hard job at all just to take a look. If you have someone with a scope they just made the job 20X easier.

[Killerfish2012]

Originally Posted by pwr hungry

Maybe the track days with the high, long periods of load help blow some of the carbon build up loose and through the motor...or maybe they are pretty caked and you don't realize it.

Possibly! Most folks on here just either daily drive their car, or perhaps go to the occational drag strip or autocross. Tracking a vehicle in the advanced group yearly, is punishment like no other. The vehicle's ecu, simply sees a 20-30min track session as an opportunity to hunt for codes. So it's extremely difficult to track an N54 vehicle. But codes show up, which would never otherwise show up until well over 150K miles, and you're constantly doing maintenance to the vehicle to keep it running.

[Killerfish2012]

Originally Posted by Jeff@TopGearSolutions

I tried to decipher how someone who cares about lap times wouldn't care about an extra 10-15 HP? That's 10-15 HP you should normally have if you were running at peak efficiency. Now you are just making your turbo's work harder to potentially meet target.

Jeff, lap times are counter intuitive. Depending on track layout, there is no difference between using stage 2+ aggressive, or the race map, which is like a 40whp difference. Unless the track has straight aways where you can get to 150mph+ like road america (3), there will be no difference in lap times in a 335I with +or-0-40whp. Remember, lap times on the circuit are full seconds, not 10ths of a second. So 40whp is really a 1/4mile difference of 4 tenths of a second.

[Jeff@TopGearSolutions]

Originally Posted by Killerfish2012

Possibly! Most folks on here just either daily drive their car, or perhaps go to the occational drag strip or autocross. Tracking a vehicle in the advanced group yearly, is punishment like no other. The vehicle's ecu, simply sees a 20-30min track session as an opportunity to hunt for codes. So it's extremely difficult to track an N54 vehicle. But codes show up, which would never otherwise show up until well over 150K miles, and you're constantly doing maintenance to the vehicle to keep it running.

Originally Posted by Killerfish2012

Jeff, lap times are counter intuitive. Depending on track layout, there is no difference between using stage 2+ aggressive, or the race map, which is like a 40whp difference. Unless the track has straight aways where you can get to 150mph+ like road america (3), there will be no difference in lap times in a 335I with +or-0-40whp. Remember, lap times on the circuit are full seconds, not 10ths of a second. So 40whp is really a 1/4mile difference of 4 tenths of a second.

This is all well and good information for those who do 20-30 min track sessions but last I checked those are few and far between. It also still doesn't prove or disprove that valve intake cleaning should or shouldn't be done if someone wants their vehicle performing at peak efficiency no matter what road or track they drive on.

Which leads me to my latest point; If you wish to have your vehicle running at top efficiency I recommend at least taking a look at your valves every 35-50K.

I see your points and I think you see mine.

[MDORPHN]

Originally Posted by Killerfish2012

Possibly! Most folks on here just either daily drive their car, or perhaps go to the occational drag strip or autocross. Tracking a vehicle in the advanced group yearly, is punishment like no other. The vehicle's ecu, simply sees a 20-30min track session as an opportunity to hunt for codes. So it's extremely difficult to track an N54 vehicle. But codes show up, which would never otherwise show up until well over 150K miles, and you're constantly doing maintenance to the vehicle to keep it running.

I've had my 1M on track (road course) for well over 100 sessions and rarely throw codes.

Neil

[Killerfish2012]

Originally Posted by Jeff@TopGearSolutions

I see your points and I think you see mine.

[Killerfish2012]

Originally Posted by MDORPHN

I've had my 1M on track (road course) for well over 100 sessions and rarely throw codes.

Neil

Neil, the last time you were at the track, you were having misfires, remember. I diagnosed it as your HPFP. Did you replace it, or trace the cause of your misfires?

[shadow191]

It's one of those things like spark plugs that just deteriorates over time so slowly no one really notices. Most people notice their car driving smoother after changing old plugs, but before they do they don't notice any issues with the old plugs unless it's misfiring. I just had mine done at 41k because there was a group buy going on. I debated back and forth since I have low miles and didn't really notice anything wrong. No codes or anything like that. I didn't even have any oil in the charge pipe or anything indicating there was a ton of blow by.

But as it turns out, there was significant buildup and the cleaning did make a difference. A tiny hesitation in the idle is now gone and throttle response is better. Overall the car just drives a little bit smoother. Don't know if it made any difference in power, but the improved idle and throttle response is good enough for me.

[MDORPHN]

Originally Posted by Killerfish2012

Neil, the last time you were at the track, you were having misfires, remember. I diagnosed it as your HPFP. Did you replace it, or trace the cause of your misfires?

Plugs.

My fuel system is still entirely stock (although that my change soon...).

Neil

[Tiago@VRSF]

Originally Posted by Killerfish2012

Jeff, I respect your opinion, but I don't care about 10-15hp at peak, here and there. I measure my vehicles performance by lap times, which have been consistent, thus I've never dyno'ed, and most likely never will.

Oh, well the fact that you regularly race your vehicle is definitely a huge contributor to clean valves.

What causes buildup is short driving intervals and lack of ringing out the motor. Heat actually helps to keep carbon off the valves

[mike_c79]

Originally Posted by Fillyo75

There are plenty of pics in this forum too. I have an 09 with 55k and am getting hesitation and sputtering under moderate acceleration between 2500 and 4000 RPMs, but no codes. I just got the Walnut blasting approved under my CPO and getting it done in the next two weeks, really happy BMW approved it. I just recently had my plugs replaced, a coil, and an injector bank. Hoping this cures my car's ills.

Dealers will approve walnut blasting under CPO ????

[Fillyo75]

I think it depends on the service rep, dealership and what not, but I am CPO and he got BMW to approve it!

[thaar]

I tried to have my dealer approve it since I was having stuttering issues that didn't throw any codes, but no dice. It eventually ended up being a bad injector, but just out of warranty, which they fortunately covered.

[Exvdubguy]

Any benefit of the walnut blast over a chemical treatment/manual scrub?

[Sigma 3]

Originally Posted by Tiago@VRSF

I'd be willing to bet you the cost of the cleaning that your valves are incredibly gunked and there will be a noticeable peak HP difference if you dyno before and after a cleaning.

I gained 23 whp after cleaning.

[Sigma 3]

Originally Posted by Exvdubguy

Any benefit of the walnut blast over a chemical treatment/manual scrub?

Walnut = more expensive, arguably better results.
Chemical= cheaper, more time consuming, if done right exellent results.
harbor frieght sells a brush kit that is used with a cordless drill. I highly recomend it if going the chemical route

try the search guys countless threads on this.

[AlpineSwift]

Originally Posted by Sigma 3

I gained 23 whp after cleaning.

Seriously? Good god that's a lot of power that was being held back. How many miles did you have on the car prior to getting it done?

[dsjr2006]

Originally Posted by Killerfish2012

Well, I come from the school of: if it aint broke, don't fix it. My car is a daily driven vehicle, and has been circuit raced at various tracks since 2009. Last year, I even managed to catch, and pass my friends modded E90 M3. I'm currently having no issues I can trace to intake valves, so untill I can see a single code, or issue at the track, I will continue to prep for this season. At my mileage, my turbos, engine, and trans are 100% ok, and because I track the vehicle, I religiously do much much maintenance than the average joe.

By the logic of if it ain't broke don't fix it, then why do you even do maintenance? I assume most of the things you do maintenance on aren't broken....

[Spoolin1]

CPO will cover getting the valves walnut blasted? I'm under CPO until Dec of this year and occassionally get some stuttering at idle while warming up, no codes though. Car is a 07 with 34k miles.

[mweisdorfer]

There are plenty of DIY's on walnut blasting. It does not look that difficult to do. You just need the gun, very fine walnut shells, an air compressor of at least 6 gallons and the intake valve adapter.

This is assuming you have a decency set of tools to begin with.

[camberadam]

VAC motorsports just did my valves & there is a noticeable difference in smoothness & high rpm pull (butt dyno confirmed). i COULD have rigged up a tool & did it myself, but by the time i factored in parts/materials & 4 hours time to tear into a car that i cant affford extended downtime, it was well worth $425. any maintanance i cant handle will go to them.

09 58k mostly rural driving, meticulously maintained. cylinder 4 looks worst to me, before & after shown.

[Sigma 3]

Originally Posted by AlpineSwift

Seriously? Good god that's a lot of power that was being held back. How many miles did you have on the car prior to getting it done?

70k. smoother idle better throttle response.

Im at 100k now. going to open up again while im in there for some....maintenance