SERVICE AND REPAIR
BMW Intake Valve Carbon Cleaning
Why Is BMW Carbon Cleaning Needed
What Is BMW Intake Valve Carbon Blasting?
Carbon blasting is a repair procedure used to fix BMW intake valve carbon build up. Intake valve carbon deposits are one of the design problems of gasoline direct fuel injection engines. There is a price to pay for the performance advantages of direct fuel injection!
Direct fuel injection allows automotive manufacturers to increase fuel mileage, power and efficiency. Modern high tech Direct Injection (DI) engines like the BMW N54, N55, and S55 engines are found in many BMW models. Direct Injection is a very sophisticated technology, with many benefits for overall engine efficiency, but there is a troublesome maintenance requirement to keep their high performance level.
The problem is caused by the design of direct injection. Direct fuel injectors spray fuel directly into the combustion chamber. The more common non-direct fuel injectors spray fuel into the intake manifold, upstream of the intake valves. The effect of fuel spraying on the valves as it enters the combustion chamber cleans the valves of deposits which turn into carbon when they harden by the heat of burning fuel.
On a direct injection engine, this valve cleaning process does not occur. Oil from valve guides, the Crank Case Ventilation (CCV) system, and turbocharger oil blow-by, build up on the intake valves. These normal deposits turn into thick carbon which builds up until it restricts the size of intake port into the engine. This restriction greatly reduces engine power, causes rough low speed running, reduction fuel mileage, as well as causing misfire at high RPM.
By 60,000 to 80,000 miles BMW intake valve carbon build-up can be significant enough to cause a very noticeable decrease in engine performance!
How To Remove BMW Intake Valve Carbon
There are two ways to remove BMW intake valve carbon:
- Expensive way: Remove the engine cylinder heads, remove the valves, and scrape the carbon off valves and cylinder head ports.
- Better way: The alternative, and much less costly method, is a carbon cleaning process that is done without removing the cylinder heads.