[Sander720]

Long story short: I have an E90 with a N47 diesel engine. High pressure pump failure contaminated the whole fuel system with metal debris/swarf. Dealers replace the fuel tank, injectors and everything in between to be 100% sure there is no metal anymore in the fuel system. Because I'll do the repair myself, I'll try to clean some parts instead of replacing them.

Parts that I replace: High and low pressure pump, injectors, fuel filter and fuel heater element.
Things that I want to clean: Fuel tank, fuel lines (high and low pressure), rail pressure regulator, fuel rail, pressure sensor

Does anyone has experience with cleaning those parts? I read something online about people who did this but does this also work on long term or do I end up with replace everything for a second time?

[lnxguy]

There's a reason why these parts are discarded and replaced. Why in the world would you even take the chance?

[fearitself165]

That sounds like a $#it ton of work and unless you work in fhe automotive field something I feel you might have trouble finding the time to do. But not as many people work as hard ot as often as me so if you have the time I would say go for it. But honestly I would be careful when testing the parts you have cleaned with the new parts, just incase. Would be horrible to put on a new high and low pressure pump and injectors to just have them all fail because some metsl shards were missed somewhere in the system.

[335dlci]

Long story short. Cleaning them will lead you to problems later.. the damage is done. You're not the first cowboy at the rodeo here...

[awenthol]

Fuel tank can be cleaned with little to no risk. Absolute worst case, you get something into the LP pump and take it out, but VERY unlikely... Anything after that would be caught by the fuel filter.

Low pressure fuel lines can be flushed. IDK why anyone would replace them. Debris won't be embedded and the possibility of stuff getting in there in the first place is improbable (feed, not rerun... Return line will have debris but will wash out). High pressure lines should be replaced for two reason--they will be most likely to sustain damage and you should never reuse them regardless--they are one time use.

Rail can be flushed. However, do not reuse the relief valve and though extremely unlikely you got anything inside the sensor element, it's probably not worth trying to reuse.

Qualifications...i worked for an oem in reliability and quality, specifically on BOSCH CPN5 pumps. I've seen every failure imagineable, worked on design and quality issues, worked through repair issues, and authored repair procedures for dealers. Aside from full rail replacement and it includng sensor and relief valve, the above is what we required. The rail, once opened up, can easily be cleaned out... It's machined and cleaned in the manufacturing process....


Additional note--make sure you replace the injector fuel return line. And it is ABSOLUTELY CRITICAL to prime the CP3 with fuel before ever cranking the engine over.