[ACM]

https://www.team-bhp.com/forum/techn...ml#post4500679 (BMW X3 (F25) at 130,000 km - Spends 25% of its time in the workshop)

Have posting about this topic, on a separate thread, The cleaning seems done manually in my case rather than via a machine. But don't know for sure.

[SS-Traveller]

Originally Posted by ACM

As per the service centre guys any Diesel BMW would have significant carbon deposits given the condition of fuel in India.

...the current engine and gearbox are only 40,000 kms and hence this is a good reflection of the condition of most new cars in less than 2-3 years of running.

BMW claims their expensive fuel additive helps in reducing this.

Originally Posted by ACM

The cleaning seems done manually in my case rather than via a machine. But don't know for sure.

What the pics in your ownership thread show are, I think, the manifolds and EGR, which have quite heavy carbon deposits. However, these areas cannot be cleaned by chemical methods as described in the beginning of this thread, nor would any fuel additive help. The only way to clean these would be manually, by opening up a lot of bolts and electronics.

However, one way to prevent, or at least reduce, this carbon build-up is to use a catch can. Given the quantum of carbon build-up that your engine is showing at 40k km, a catch can should be considered strongly.

What is the interval at which you replace the engine oil?

[ACM]

Originally Posted by SS-Traveller

What the pics in your ownership thread show are, I think, the manifolds and EGR, which have quite heavy carbon deposits. However, these areas cannot be cleaned by chemical methods as described in the beginning of this thread, nor would any fuel additive help. The only way to clean these would be manually, by opening up a lot of bolts and electronics.

However, one way to prevent, or at least reduce, this carbon build-up is to use a catch can. Given the quantum of carbon build-up that your engine is showing at 40k km, a catch can should be considered strongly.

What is the interval at which you replace the engine oil?

1) Been replacing oil at 9,500-10,000 kms as per conditions based servicing system of BMW.

2) As per BMW service team at infinity motors. This would be the condition of EVERY Diesel Engine in about 30,000 kms, but they don't do any carbon cleaning unless asked for or unless a problem is reported. I did report a sluggish engine performance and a faster move towards service due date.

3) In warranty under BSI no individual would carry out anything extra outside the service centre that is not standard practice. It would void the warranty. Too expensive.

4) Via my post I am conveying that Most Diesel Engines are possibly running with carbon build-up in these places and even under warranty and extended amc they are not getting attended to by any manufacturer. But should be.

5) No way to know if my hypothesis above is correct but by opening up a few.

I agree that the chemical methods described in this thread would not clean the EGR and Manifold carbon build-up. As per BMW, their fuel additives help reduce this.

Best I post the snaps here too for the convenience of readers.

[ashtwinks]

Very clearly this engine needs a catch can.

I know this is an old thread but could not resist asking:

- Do you by any chance drive with a heavy foot?
- What reason has been given by the technician for such high build up of carbon?

You can put a catch can and whenever you take the car to the station you can remove the tubes unless the ECU is able to detect this pressure difference in the crank case.

[krsna777]

Originally Posted by GTO

The marketing spiel would have us believe that decarb is indeed a magic solution that'll make our engines run smoother, faster and more efficiently. Personally, I think it’s all rubbish. Shom,

I honestly feel this thread needs to be revived.

Decarbonisation is not a myth. Ofcourse its not needed in older engines, just use of good fuel and timely change of engine oil will keep the engine in good condition.

But the the new Direct injection engines especially all the european engines, decarbonisation is a must IMO.

Originally Posted by DrANTO

Interesting post. This is the first time I am hearing about something like this. But still I am in dark about the actual theory behind this; I am not sure whether the effect will last longer than a few thousand kilometers.

The theory is very simple, In older engines (port-injected engines), air and fuel are mixed before entering the combustion chamber. So the fuel kind of acts like a cleaning agent for the intake valves.
This is not the case with DI(Direct injection engines), where fuel is pumped into combustion chamber directly via another entry. Blowbacks from combustion chamber result in escape of vapors to the back of intake valves and get deposited there periodically.

As the carbon deposits increase the air flow is not optimum. The ultimate purpose of Direct Injection is defeated, as now the fuel and air mixture is not optimum. Sometimes the intake valves are not closed properly and in the worst case, result in more wear and tear of piston rings.

Symptoms are reduced performance, poor fuel economy, engine knocking etc.

which engines are effected?
All German manufacturers. If I'm not wrong VW till date has not put anything in place to address this. Hyundai GDI engines also work the same way. Not sure if this is updated in newer engines though.
Toyota is the only company I know of which didn't have this problem as they used both port injection and direct injection.
Always remember Japanese are the best period.

What are the preventive measures?
IMO, nothing can be done to fully prevent this issue.
Italian tuneup kind of helps as the air intake is more in spirited driving. (Heavy foot helps)
Catch Cans are also useful, but its hassle to install and regularly change the cans.

What needs to be done.
No chemicals/additives can remove these deposits. They don't touch this area.


Best way is to manually clean the intake. Walnut blasting is the most preferred way. Of course this needs to done be with utmost care. Any muck if seeped into the combustion chamber will result in a total loss.
I'm not sure if FNGs do these.

This is the best example in our forum to depict this.

Originally Posted by ACM

As per the service centre guys any Diesel BMW would have significant carbon deposits given the condition of fuel in India.

Since mine had a new engine at 90,000kms the current engine and gearbox are only 40,000 kms and hence this is a good reflection of the condition of most new cars in less than 2-3 years of running.

BMW claims their expensive fuel additive helps in reducing this. I frankly used a lot of it and this was the condition.

This is just plain wrong. Higher octane fuel helps to some extent but cannot prevent the build up completely. Even if we go to germany, you will find BMWs having this issue. All blame should go to the decision of not having port injection. And as said no additive helps.

30-40K kms is good enough time interval to do this manual process.

[Aroy]

Carbon build up is a fact of life if the engine never heats up properly. Short runs are one reason. Second one is incomplete combustion during stop-and-go traffic. That is apart from bad fuel.

There are two types of build up :

1. At the valves and exhaust.
2. In the throttle body.

Italian tune up helps a lot in decarbonising the engine part, but is not as effective for
throttle body.

In the opinion of most experts, unless specifically recommended by the manufacturer, fuels additives cause deposits to build up in the engine and valves. So be careful.

[georgesunnyt]

Originally Posted by ACM

1
2) As per BMW service team at infinity motors. This would be the condition of EVERY Diesel Engine in about 30,000 kms, but they don't do any carbon cleaning unless asked for or unless a problem is reported. I did report a sluggish engine performance and a faster move towards service due date.

I asked my BMW dealer if they would clean my intake manifold to which they said No. They said they would only replace the intake manifold. Next time I see them , I'll rephrase my question to if they do "carbon buildup" cleaning

[Aroy]

Originally Posted by georgesunnyt

I asked my BMW dealer if they would clean my intake manifold to which they said No. They said they would only replace the intake manifold. Next time I see them , I'll rephrase my question to if they do "carbon buildup" cleaning

As suggested, take your car for spin on highway. A constant run at 90-120 km/h for a couple of hundred kilometers will get rid of all but the most stubborn carbon deposit.

The above is called "Italian Tuneup" and works every time. The FE which normally drops by 20%-40% of clean engine comes back miraculously, so does acceleration and engine response.

[scorpian]

Originally Posted by georgesunnyt

I asked my BMW dealer if they would clean my intake manifold to which they said No. They said they would only replace the intake manifold. Next time I see them , I'll rephrase my question to if they do "carbon buildup" cleaning

No amount of high speed driving is going to clean the intake manifold as it never reaches high temperature as the exhaust manifold.The only way is to open it and clean it manually.The amount of carbon in intake manifold due to egr is enormous enough to affect engine performance.Almost all ports get narrowed down and affects air flow.

[Aroy]

Originally Posted by scorpian

No amount of high speed driving is going to clean the intake manifold as it never reaches high temperature as the exhaust manifold.The only way is to open it and clean it manually.The amount of carbon in intake manifold due to egr is enormous enough to affect engine performance.Almost all ports get narrowed down and affects air flow.

I agree. It is not a very difficult, but laborious task. There are some imported products in the shops that can reduce the carbon coating in the intake manifold. You can try that. If not satisfactory, then opening up the intake manifold & throttle body and mechanical cleaning is needed.

[CLS_06]

Hi all
this is my first post on team bhp
pardon for any posting errors

just want to know that is it good to get HHO de-carbonisation of engine
i have 2 cars that i am thinking of getting done
1. Ritz vdi 2013 (current odo at 1,20,000 km/-)
have completely followed service schedule
but there is a heavy amount of black smoke on hard accelerations

2. innova v (diesel) 2012 (current odo at 80,000km)
but have zero black smoke at any given moment

Has anybody got it done
what can b pros & cons.

(request to mods If it doesnt belong here move to separate thread)

[bikertillidie]

Just came across this thread. Makes for a very interesting read.

Modern direct injection engines are bound to end up with a fair amount of soot/carbon deposits on intake valves due to their very design.

What's the best best way to decarbonise such engines?

Introduction of cleaning agents/fuel additives does not really help here as fuel is sprayed directly into the combustion chamber..

Any thoughts?

[Kosfactor]

Originally Posted by bikertillidie

Just came across this thread. Makes for a very interesting read.

Modern direct injection engines are bound to end up with a fair amount of soot/carbon deposits on intake valves due to their very design.

What's the best best way to decarbonise such engines?

Introduction of cleaning agents/fuel additives does not really help here as fuel is sprayed directly into the combustion chamber..

Any thoughts?

Ideally, as long as the engine uses OEM consumables including engine oil, good quality fuel etc - also if the engine is well tested in our conditions, fuel quality and all, there should be no issues for the life of the engine or say 3L Kms at least.

[bikertillidie]

Originally Posted by Kosfactor

Ideally, as long as the engine uses OEM consumables including engine oil, good quality fuel etc - also if the engine is well tested in our conditions, fuel quality and all, there should be no issues for the life of the engine or say 3L Kms at least.

Thanks.. Am experiencing this first hand on a friend's Ford Figo 1.4 diesel which has covered a mere 73K km. The engine suffers from sticky valves caused by carbon deposits and occasionally misses on one cylinder as the intake valve fails to close / seal off the cylinder completely.

The vehicle is in excellent condition otherwise and has always been routinely serviced at authorised workshops.

Opening up the manifold and cylinder head appears to be the only option left, unless there's some other way to clean up the deposits effectively.

[scorpian]

Originally Posted by bikertillidie

Opening up the manifold and cylinder head appears to be the only option left, unless there's some other way to clean up the deposits effectively.

I would say the EGR is the reason for the extreme carbon soot buildup. One of the reason i did a remap was to close the EGR and also post that i removed the intake manifold and it was clogged by over 70percent at 88k kms.

My advise would be to get a soft remap done and close the egr and get the intake manifold and head cleaned once so that you will not face this issue again.