Carbon Build up Explained

Carbon Doctor is a niche business that focuses on the cleaning of carbon on valves and inlet ports caused by direct injection. Other services offered are the cleaning of inlet tracts of diesel vehicles as well as any engine component using walnut shell blasting.


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George Smooth
BT Golf
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Carbon Build up Explained

Postby George Smooth » Mon Jan 14, 2013 10:44 am

Since I am offering a cleaning service I though I should do a write up on what exactly this carbon build up is and why it occurs.

Due to modern unburned hydrocarbon regulations, vapors from the crankcase are usually vented into the intake stream in order to prevent oil droplets from escaping through the exhaust. In a port injection traditional engine, these droplets are ‘washed off’ the neck of the intake valve by a relatively constant stream of fuel. In a DI (direct injection) engine, the fuel doesn’t touch the intake side of the valve. As a result, the droplets have a tendency to bake onto the valve and cause significant carbon deposits causing a reduction in performance, rough idling, difficulty starting and eventually bad sealing of the valves. To add to this effect, many advanced DI engines also include exhaust gas recirculation in order to lean out the combustion mixture and reduce in-cylinder temperatures for certain combustion modes (reducing NOx emissions). Since DI combustion has the ability to produce far more soot than premixed combustion (port injection), the problem is magnified.
Even more alarming is that these deposits can dislodge and damage other downstream components (turbochargers, catalytic converters, etc.). Manufacturers have added systems to capture these oil droplets and particulates, but no system is 100% effective. As a result, there are many disappointed early adopters with large repair bills. Even diesel engines haven’t been immune to these issues.
Symptoms of carbon build up are typically:
Gradual increase of consumption
Rough Idle
Detonation
Leaking valves
Power loss
Misfires
Engine check lights

Some pictures of various model cars to get a general idea of what it looks like.

2.0TFSI as found in Audi/Golf

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N54 X35i

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Porsche Cayenne

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Peugot/ Mini

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Mazda 2.3

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[undefined=undefined]Our process in a Nutshell:[/undefined]

At Carbon Doctor we have adopted a tried and tested method of cleaning the carbon of your valves and inlet ports. Walnut shell blasting has been used for the better part of the century to clean sensitive components ranging from pc boards to jet turbines. This is also important when used in the cylinder head of a vehicle as the majority are made of aluminum which is highly sensitive to surface changes.
Using the right size and density the walnut shell is blasted into the intake track using a BMW Blasting Tool creating a clean surface whilst preventing any damage to sensitive engine components. The process is as follows:
1. Removal of inlet manifold following manufacturers procedures
2. Inspection of the valves and rear of the throttle body
3. Closing of the valves on the port to be worked on by crankshaft rotation
4. The carbon blast procedure is conducted whilst simultaneously vacuuming carbon deposits and walnut shell. This procedure is totally self contained and does not create further clean-up work in the engine bay.
5. Repeat for the rest of the ports
6. The inlet manifold is then replaced using new factory manufactured gaskets.
Carbon Clean Services uses this process as it is both cost and time affective guaranteeing a same day turnaround in order to get the vehicle back on the road. Other methods currently used necessitate the use of strong chemicals and metal brushes. This unorthodox method requires the inlet to be soaked overnight creating both a time delay for the customer as well as facing corrosive risks on aluminum components. Further more carbon is not completely cleaned and small deposits left behind will increase build up exponentially as they create a trap for the next cycle of build up.

Clean and polished
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08 335i
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15 G7 TSI
16 Audi RS3

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RPGTI
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Re: Carbon Build up Explained

Postby RPGTI » Wed Jan 30, 2013 7:09 am

How long does a average job take to do?
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Tha_Game_GTi
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Re: Carbon Build up Explained

Postby Tha_Game_GTi » Wed Jan 30, 2013 7:27 am

How often would one need to clean the build up?

Thank You for the info.
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Re: Carbon Build up Explained

Postby George Smooth » Wed Jan 30, 2013 8:39 am

RPGTI wrote:How long does a average job take to do?


On a TFSI about 5 hours. It's relative to the complexity of removing the manifold as well and how much carbon is found.
08 335i
14 G7 R
14 G7 GTI
16 G7 GTI
15 G7 TSI
16 Audi RS3

George Smooth
BT Golf
Posts: 2243
Joined: Sat Nov 22, 2008 12:42 am

Re: Carbon Build up Explained

Postby George Smooth » Wed Jan 30, 2013 8:43 am

Tha_Game_GTi wrote:How often would one need to clean the build up?

Thank You for the info.


I would do it at a minimum of 50,000km. The fuel savings negate the cost long before that with the performance gains being a added benefit. Most clients have opted to re book at 30,000-40,000.
08 335i
14 G7 R
14 G7 GTI
16 G7 GTI
15 G7 TSI
16 Audi RS3

Cornel
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Location: Kuruman

Re: Carbon Build up Explained

Postby Cornel » Wed Jan 30, 2013 8:45 am

if it may be asked here. what do you charge on a job like this?
in my case i have a 4cylinder 1.6 fiesta
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Re: Carbon Build up Explained

Postby Ridoooo » Mon Apr 28, 2014 7:22 pm

So is the head not removed for this process? I really need to do this. My tfsi has 177k kms on it. Lol.
JETTA 5 2.0TFSI
E TUNERS STAGE 2 + NO LIFT SHIFT
E TUNERS DP
E TUNERS THROTTLE PIPE
CTS INDUCTION
S3 INTERCOOLER
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COBRA 30MM DROP SPRINGS

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