BMW 520D D clean user testimonial – Carbon sludge worry-free

I was lucky to meet with an intake manifold cleaning expert. Recently there has been lots of big incidents with BMW catching a fire while driving. While BMW Korea officially commented that EGR is the culprit of this problem, some people said the problem might not be limited to EGR. With this said, as a BMW owner myself I wanted to ask a lot of questions to someone who’s understanding BMW in depth.


Mr. In-kyu, Song
Mr. In-kyu, Song , D Clean user


Mr. In-kyu, Song who is also a BMW owner and intake manifold cleaning expert himself, he has a lot to say about this tragic incident. First off, he’s been a loyal BMW customer over 10 years. During 10 years, he has driven a few BMW models including current BMW 520D. BMW is the most fun car for him. But most importantly, he trusted BMW. “Reliability” was the main reason he chose BMW. Mr. Song never expected BMW would be accused of a dangerous car. He said, he is indeed in deep shock.


D Clean - Red components
D Clean – Red components


He was told from BMW service center that his car is in very good condition therefore there is no risk involved with EGR malfunctioning. Evidently, he took care of his car especially as an intake manifold cleaning expert, his intake manifold area is very clean.  Usually over the years, carbon sludge is building in the intake manifold, but after manual cleaning, he installed D Clean, which took care of the job at all times.


D Clean - Red components
D Clean – Red components


D Clean discharges special liquid once in a while (depending on its logic) cleans intake manifold area before any carbon components starting to buildup. According to Mr. Song, it’s best to install D clean when you purchase a new car. D Clean could remove existing carbon sludge buildup, but it would take a while.

Mr. Song explained that carbon sludge buildup would be bad for EGR. Narrow air path due to carbon waste does interfere with what EGR is supposed to do in a normal condition. If EGR doesn’t do its job, DPF got big pressure. So everything is all connected. Even if EGR is fine, if DPF got a lot of pressure after replacing of EGR, this might cause something bad, potentially.


BMW owners especially 520D owners got a lot of stress lately.

Mr. Song knows internals of intake manifold area in relation with carbon sludge buildup, he’d tried every new products available in the market that claims to remove carbon sludge. Among them, D Clean seems to be the best option possible. Mr. Song is very happy with D Clean . He clearly felt his car being very smooth after installing D Clean just like he would feel after intake manifold area cleaning manually. Since D Clean uses liquid, but it didn’t need to be refilled often. According to Mr. Song, he feels that it would suffice to refill it every time you change your engine oil if you’d install it when there is no carbon sludge buildup.

No need to disassemble engine components to clean carbon sludge!

Mr. Song said he would recommend D Clean to every diesel car owner, especially BMW car owner.




From his job experience, frequent stop and go situation facilitate carbon sludge to build up in the intake manifold area. If you drive long distance with high speed often, you wouldn’t have much carbon sludge buildup than the one whose driving at the congested city area where you have to make a stop and go often. So maybe this is why we have so many old BMW cars on fire while driving recently in Korea because there has been enough carbon sludge buildup happened which triggered big pressure on EGR or DPF at the same time.


D Clean cleaning liquid
D Clean cleaning liquid

Mr. Song said, “BMW must take great care its owners. They all chose BMW because they trusted BMW.” I would choose BMW again if they resolve this issue with honesty.

I hope so, too. As I like BMW for its fun and performance driving experience, I don’t want to choose other brand in the future.

  • About recent BMW incident, please read a following post.