BMW on fire – carbon sludge buildup / EGR

Recently we had a series of uncomfortable events concerning BMW car. BMW car has been very well known for its high performance and safe car image. But they got in fire issues in the engine room. A lot of cars caught in a fire in this summer during driving. Fortunately as soon as fire got started, BMW car itself stopped itself, so all passengers had the time to escape before it got burned down seriously.

Reference link from BBC :


Recently I bought one for myself. I wasn’t aware of this incident when I bought it.


Including BMW owners, everyone in Korea got shocked. How come reliable car like BMW…. This was on the media for weeks. It turns out EGR (which reduces toxic components such as NOx) got stuffed by carbon sludge buildup in combination with usual hot weather in Korea, it became the culprit of the problem. BMW officials in Korea announced a recall for the old EGR module. At this point, no one can’t say this is the definitive answer to the problem but carbon sludge buildup seems to be the part of the problem if not all.




Why do we need EGR?

In the Diesel engine, especially with a turbo engine, the air from the engine is reused (recirculate gas exhaust) roughly about 50% (this varies depending on the car manufacturers). When the air is reused, toxic gas is produced such as NOx(nitrogen oxide) as a byproduct, ERG’s role is to reduce this substantially.

In other words, if it were not for high performance (turbo), EGR might have not been necessary. (Disclaimer: Note that I am not an automobile specialist, so this might be my own opinion biased by the media.)


High performance car might be in the same boat.


In recent events, BMW officials pointed EGR as the main culprit of the issue. While this may not be the definitive answer to the problem, if this is true, more fundamental problem is from carbon sludge buildup starting from the intake manifold area. When carbon sludge got buildup in the intake manifold and speeding to other components of the engine, then it’s quite possible that this triggered the “airway to EGR” got narrowed. Then eventually, pathway to EGR got punctured. Again this might be just a wild speculation but it’s also a fact that high performance car has more carbon sludge buildup issue.


Carbon Deposit (also known as Carbon Sludge)
Carbon Deposit (also known as Carbon Sludge)
Carbon Sludge buildup in the intake manifold
Carbon Sludge buildup in the intake manifold


Some people say “why not disable EGR, if EGR is the culprit of the fire issue. After all, DPF before the exhaustion will take care of the air pollution issue.” This is a really dangerous idea. Without EGR doing its job, DPF won’t survive much longer. DPF is designed to do only so much, so it will die with heavy NOx and other unwanted gas exhaust.

Well, there might be a better solution according to this local automobile master Mr. Park.



Long story short, Mr. Park thinks instead of fixing EGR which might be one tiny part of the big problem, it’s a lot better if BMW offers carbon sludge cleaning service after 60~70km for free(as this is their design flaw in the engine.)

If this is true, I believe D Clean will play a very important role with the current BMW fire issue.

Check out this link for D Clean information.