2004 BMW E53 3.0d M57 - Rough idle & cleaning injectors

[AUSBMX]

Hi all,

Has anyone had much success pulling apart and cleaning the Bosch 131 in the E53 M57 engine? Solenoid type, not piezo.

I just bought a 2004 E53 3.0d (M57), with about 192k km and a rough idle particular when cold. It seems to drive well about 80 km/h and above.

Very poor values (except cyl 2) in smooth running injector test when engine is cold:

Cyl 1: -1.6 mg/stroke
Cyl 5: -1.3 mg/stroke
Cyl 3: 1.1 mg/stroke
Cyl 6: 5.2 mg/stroke
Cyl 2: -0.7 mg/stroke
Cyl 4: -3.0 mg/stroke

And only ~2 poor injectors when the engine is warm:

Cyl 1: -0.8 mg/stroke
Cyl 5: -0.8 mg/stroke
Cyl 3: 0.1 mg/stroke
Cyl 6: 5.0 mg/stroke
Cyl 2: -0.6 mg/stroke
Cyl 4: -3.2 mg/stroke

What's recommended action here - clean, install refurbished, or just bite the bullet and buy new? I had a diesel mechanic tell me expected lifetime for these injectors is only around 190k km.

[Clavurion]

First change or refurbish that Nr.6 injector. Nr.4 could be correcponding to Nr.6 high value and could at this point be neglected. Depends what's the local supply regarding Bosch refurbished injectors, local refurbishing and your own skills. The injectors can usually be refurbished with a few special tools, ultrasound cleaner device and quite cheap parts if needed. I have refurbished a bunch of these with a friend of mine. Currently the refurbished injectors on mine are running beautifully with 412 tkm on the clock.

[AUSBMX]

Thanks mate. I think that will be the plan (new are $500+ here), I'll pull both injectors and unscrew the tips and clean the nozzle / valve / spring etc in the ultrasonic cleaner. Seems to be a few videos of the process floating around YouTube now. What solvent do you usually use? Thinking just IPA in a jar.

[Clavurion]

Originally Posted by AUSBMX

Thanks mate. I think that will be the plan (new are $500+ here), I'll pull both injectors and unscrew the tips and clean the nozzle / valve / spring etc in the ultrasonic cleaner. Seems to be a few videos of the process floating around YouTube now. What solvent do you usually use? Thinking just IPA in a jar.

It can be done but I can't recommend it unless you first check some tutorials and buy or manufacture a few special tools. Many times one of the main culprits is the internal teflon seal between piston and core. So cleaning the nozzle alone might not do the trick.

[AUSBMX]

Could you point me in the direction of a tutorial/guide? What special tools do you recommend?

[AUSBMX]

Finally found some time to pull the injectors and remove the nozzles/ pin/ shims / springs etc for an ultrasonic bath in 99% IPA for about 30 minutes each, followed by soaking in diesel before reassembly + new copper washers. Tip for others, I found hot glueing some scotch brite to the end of a 3/8" extension a good way to clean up the injector seats in the head.


I put my borescope down the injector holes for a quick look, and found what looks to be possible pitting on the cylinder wall closest to the injector in cylinder 6. Maybe an artefact of the incomplete combustion?


For reference the before cleaning warm values:
Cyl 1: -0.8 mg/stroke
Cyl 5: -0.8 mg/stroke
Cyl 3: 0.1 mg/stroke
Cyl 6: 5.0 mg/stroke
Cyl 2: -0.6 mg/stroke
Cyl 4: -3.2 mg/stroke


And note, I switched the physical injectors around after cleaning to see if the worst offenders (cyl 6) move with the injector or stayed with the cylinder.
Before injector # / After injector #
1 / 6
2 / 4
3 / 3
4 / 5
5 / 2
6 / 1

And after cleaning values (drove for about 10 minutes):


Cyl 1: -0.9 mg/stroke
Cyl 5: -1.5 mg/stroke
Cyl 3: 1.2 mg/stroke
Cyl 6: 1.1 mg/stroke
Cyl 2: 0.3 mg/stroke
Cyl 4: -0.1 mg/stroke Which all seems pretty reasonable, however I am a little concerned by what I think I saw down the cylinder 6 - but surely if I had compression issues here it would show up in these correctional values right? Had me extra concerned as at first start up after cleaning the value for cyl 6 was still quite high even though it was a different injector, but that seemed to settle after driving.

Keen to hear any thoughts.