strfyr51 wrote:Years ago we had problems with the CFM-56-2 and the -3's We figured out the fuel nozzles were clogging and leaking and failing due to being coked up. We instituted an engine wash program which cleaned the fuel nozzles and all of that ended. But only after having changed 100's of fuel nozzles first
a) How do you clean the fuel nozzles from carbon deposits? using regular compressor wash, in engine shop (combustor casing removed), through spark plug holes, or through connecting the cleaning liquid hose with fuel line upstream the fuel nozzles?
Modern engines have engine wash (called also compressor wash mostly because the goal is to clean the compressor blades) even though the cleaning liquid pass through the gas path of the engine. If I am not mistaken, in some old engines like JT8D the combustors were cleaned through spark plug holes (through the combustors casing)
b) Why modern engines are not subject to cleaning through the spark plugs as older engines such JT8D?
c) Are combustor and fuel nozzles on modern engines are less prone to carbon deposits than the older engines or the current compressor wash (modern wash equipment) is efficient to remove the carbon deposits?
d) I am wondering if the AMMs (aircraft maintenance manual) recommend the use the borescope to inspect for carbon deposits in the combustor and the fuel nozzles or not?