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Carbon buildup on the Mazda 6 2014 2.2 Diesel


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Hi everybody,
I'd appreciate some assistance and guidance.
I have a 2014 2.2 diesel with slightly over 79k miles on it. I bought it brand new and had it serviced by Mazda with all of the needed recalls and upgrades.

So the dpf inspection needed light came on the other day? So I scheduled an appointment with Mazda to get this looked out.

It took a call from the garage to be informed that they attempted a force regeneration on it but it could not be done?
According to what I've been informed, the injectors are defective, several sensors need to be replaced, and the head has to be de-coked due to carbon buildup, yeah, and the dpf is most likely clogged. I also omitted to mention the increasing oil price. Has anybody else had problems with their vehicle after the engine software update (AJ024*) and the intake shutter valve (AK016A) recalls?  I'm not sure whether any of these recalls contributed to the failure of these components since the garage said that one item failed and then other parts were removed.

On the Honest John forum, I read that someone had the shutter valve updated and the garage conducted a carbon clean, which I don't believe was done to mine.

Grasping at straws I'm not sure, but I was wondering if anybody else had similar difficulties and what the outcome was, since the expense of repairs is going to outweigh the value of the vehicle, so I may as well scrap it, which is not what I expect from a 5 12 year old automobile.

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How far did you get with that? After having the dealer clean the sumo pickup and replace the oil pressure sensor twice in the previous six months because of increased oil levels and pressure difficulties, I discovered that the cause was the £10 injector seals.

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I just went through something quite similar. I have a 1967 license plate, and my car has just over 26 thousand miles on the odometer. The engine management light has illuminated, and Mazda has indicated that the vehicle's motor requires a decoke. I find it hard to think that an engine with such little mileage would need one

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The very low mileage may be the reason the engine has to be de-coked. Only 2000 miles a year, or roughly 32 miles per week throughout a year, have been driven on average by the vehicle. When operated in this manner, the engine has never had a chance to fully warm up and burn off all the contaminants that contribute to the buildup of carbon. It is possible that it was only ever used as a shopping vehicle for extremely short trips. Engines must be used often to stay in top condition. The engines of automobiles that spend the most of their life on highways shouldn't ever need de-coking, in my opinion.

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26,000 miles over three years equates to around 8,000 miles each year, which is the UK average.

You can drive once a week to get that miles, or you may drive every day. Even if you drive every day, it is still 20 miles per day, which is enough to warm the vehicle even in stop-and-go traffic. When the engine is cold, the stop start mechanism does not function.

The carbon buildup issue is more of a design characteristic of these engines. They were not built to be driven in stop-and-go traffic, yet that is how the roads are today.

Nowadays, the phrase "driving on the highway" might be deceptive. The freeways in the UK have the highest speed limits, yet try travelling to work and you'll discover that you spend a lot of time stopped with the handbrake on.

Then you try again on weekends, and it's somewhat better. The majority of individuals drive their automobiles to work and away on vacation. In both cases, they utilize the highways merely to be parked and idling to remain warm or cool.

Highway driving used to imply faster speeds, which required more rotations. This had the capacity to remove accumulated dirt. However, since modern highway traffic is sluggish, the statement should be replaced with something like "drive the car long enough without stopping."

The speed and rotations are unimportant as long as you can keep the automobile going in top gear. Then you have the opportunity to burn off the accumulated dirt.

However, the natural combustion cycle of these engines produces an excessive amount of carbon. You cannot prevent dirt accumulation if you simply use your automobile for commuting, shopping, and vacations.

Fortunately, most drivers do not face this issue since they finance their vehicles and exchange them every couple of years. For the unfortunate drivers who do not do so, the decoke is an excellent way to compensate for the poor design.

The second solution is to get some fresh air by driving away on weekends, although most people do not do this. If people gave the automobile some respectful time to go without stopping, it may clean up a little, but the issue would return with the current traffic situation.

When the latest version of E Class was debuted, the engine was said to run at 1,100 rpm at 70 mph owing to its 9-speed gearbox. So, contrary to popular belief, driving on the highway will clean up the engine. This will occur not because of the low revolutions, but because the engine will run continuously.

Mazda never got the diesel engines right, but they're not going to acknowledge it.

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Similar problems to yours existed with my Mazda, including a rising oil level and sporadic EM lights with a fault code indicating a clogged dpf.
Once a month, I drove the vehicle on a vigorous drive, maintaining the revs over 2k in third or fourth for more than 30 minutes after purchasing a code reader and deleting the codes.
Problem was never repeated.
It's important to note that no matter how you drive, your engine won't do a regen until the fault code is cleared.

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