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A brief inquiry. I have been advised against using fuel additives or cleansers on BMWs, although there must be some that are acceptable.

My car operates excellently, but I believe it requires a thorough internal cleaning. The EGR requires cleaning and declogging.


Thank you.

BMW sells gasoline additives directly.
I utilise Millers Echo-max in both of my business models and in my management board as well.
I have utilised this for approximately 15 years or more and have discovered that it performs effectively, yielding improved miles per gallon after several weeks of use.

I have never utilised any additives; they seem like snake oil to me. If your vehicle operates as intended, such as on longer journeys occasionally, and I have consistently used Asda diesel gasoline, which is conveniently located nearby, I have never had any operational issues that may be attributed to the fuel.

My local garage and MOT facility utilises Forte. It is a father-son establishment, and the traditional father was first suspicious about the son's usage of the product; nevertheless, he was persuaded when vehicles that had failed emissions tests subsequently passed after the application of injector cleaner.
No elixir will eliminate the debris from the inlet; it requires manual removal and raking. Utilise double gloves when performing that task to prevent a significant mess.
It was certainly worthwhile; after completing mine, it felt like a rocket ship, and I subsequently had the EGR programmed off to avoid future accumulation by BWChiptune.

I recall applying carburettor cleaner to a friend's EGR valve that I was servicing. The spray bounced off the EGR, resulting in a splatter all over my face, leaving me with carbon residue smeared across my skin. Removing it was quite a challenge, as my face became red and irritated. I also experienced a similar situation with an E46 330d, where I ended up with the same on my hands.

I have utilised Fuel Doctor in diesel vehicles for over ten years without encountering any problems. To my knowledge, it is the sole system that decomposes water from condensation or supply pollution, effectively filtering out particulates. It also addresses bacteria, which I can attest is quite troublesome to eliminate from a fuel system. Allegedly provides lubrication during the process and incurs an additional cost of approximately $1 every fill. Despite all above, I remain an enthusiast of extended high-speed runs. A duration of several hours at a speed of 100 km/h to eliminate carbon emissions.

I recently obtained a 2010 330d with 170,000 miles on it. Commenced utilising Fuel Doc, however after only 2000 km, I opted to replace the induction box and inspect the throttle body, EGR, intercooler, and associated piping.


Here are some images of the swirl flaps and throttle body.

I lack confidence that Fuel Doctor or other fuel system cleanser will restore this buildup to its original condition.

The intercooler and hoses had oil, albeit less than anticipated. I rinsed with petrol and dried in the sun, then expelled compressed air from the rear into the radiator core, which dislodged more sand and fine gravel than anticipated from 15 years of usage. I am implementing a catch system to manage oil vapours and disabling the EGR via the ECU.

However, for those who may pursue ideas related to the inlet manifold. I have read about walnut blasting; but, I am too frugal to consider it. Furthermore, while examining my engine, there appeared to be significantly less accumulation compared to the swirl flaps. Equipped with a toothbrush enveloped in a cloth and saturated with petrol, I proceeded to scrub. Regularly altering the rag location resulted in all the ports appearing rather satisfactory in a short time. Subsequently, the mounting surface was cleaned using 400-grit wet and dry sandpaper, preparing it for assembly.

I believe any occupation involving diesel is unclean.
It permeates your skin.
I still refuse to relinquish my diesel vehicles, haha.