What are the effects of a carboned up motor? My Mercedes gets excellent fuel mileage but lately when cold the first time I take off I get a little bit of a knock, plus it has been doing a bit of blackish grey smoke whether at idle or at speed. I went out and got some new Bosch nozzles for it (going to build up a POP tester), but I'm wondering if it is just the motor being carboned up from being ran so softly and slowly. I should probably take it for a interstate drive and give it an italian tune-up, going 80mph for a little while should help clean it out. For what it's worth I have the timing advanced a degree from stock setting, a K&N filter on the turbo, and the Cummins equivalent of the AFC enriched a little bit.

 

Get rid of the K&N filter...they're advertized to let more air in, but they also let more dirt in. One guy on here tested one out by putting it on a clean floor in the garage and tossed some dust over it and found that some of the dust actually fell through the filter to the floor! Imagine what it does w/ the turbo spooled up!

Yeah, take it out on the highway. Better yet, some mountains. Drive it at about 75 mph for 200 miles. Put some Powerservice Diesel Kleen in your tank too...that'll help clean it out. The more you make the turbo scream the hotter your engine is getting and the more carbon that's being burned out.

 

Wow, that sounds very scientific. Seems like the guy determined the results before he even started or the whole story is BS.
Lots of people run K&Ns without a problem, you just have to follow their instructions, throwing dust on them on the garage floor isn't one of them.

 

I'm not to big of a fan of K&N anymore, I had an exhaust leak on the MB and the amount of stuff that made it through coating the turbine with a powdery layer of carbon was a bit disappointing. Also at the same time my talon has been letting a bit of dust through as I noticed in the hoses after the turbo. I think the K&N when clean has horrible filter performance but once used a while it improves significantly and makes for a decent filter. It actually seems like I read here someone ran their K&N for 1000 miles and their silica content in their motor oil went up 10X relative to his previous test with a paper air filter. The K&N sounds so much better than the stock filtering unit, I can hear the turbo spool all the time now so I can just drive around with a smile. Anyway I'll probably try AFE next time, but as long as these K&Ns don't get cleaned I think they'll be ok.

Sounds like a plan, I've got a can of that stuff around from the previous owner. To bad we don't have mountains here otherwise I'd just drop it a gear and let it push it up the hill until redline with full boost.

 

Yeah, that's right...the whole story is BS...in fact, my whole life is BS right now...I'm actually dead.

 

No need to take it personal, Bill has just had good experience with K&N. He has something like 250k miles on his original K&N filter, but at least he only cleans it every 75k miles or so. Some people take it a bit far and clean it with every oil change which is just absurd.

I've had K&Ns on three of my cars, I do feel they are good just not good enough. I'd like to try a different manufacturer next time.

 

I'm not rude to anybody, yet others are rude to me. I'm tired of that BS. It's been happening more and more lately. It's been a privilege to be here, but the privilege has been used up. I'm outta here never to return.

 

dont take it so personally is just someones opinion they can choose to beleive it or not if they dont thats there problem

 

That's why there are Fords, Chevy, Dodges, and whatever.

Opinions are like (Insert favorite euphemism for the south end of a North-bound whatever). Everyone has one.

I used K&N before, now using a Scotty, will eventually end up purchasing a Uni, then ...who knows.

Life's too short to get PO'ed over an air filter that YOU chose for your truck anyway.

 

welder27, no offence was intended to be directed towards you, sorry if it came off that way.
You say right in your post that info came from someone else, that's why I left your name off the quote.
If anything he's the one who should be offended...