Wet vs dry diesel injectors

[JHZR2]

Pulled the five injectors from my Mercedes OM602.96 2.5L turbo diesel. The car has 228k mikes and runs and drives beautifully. It has a few weak glow plugs and starts easily with no help.

That said, experience tells the community that Injectors start to unbalance In terms of pop pressure around 100-150k, and the atomization tends to degrade around 150k, making it prudent to swap nozzles. Experience shows that higher mileage Bosch nozzles wear to produce more of a stream than a mist. Since I don’t have history on the injectors, and needed to pull the intake anyway to do glow plugs, I figured it was time.

I pulled them, and found that two were wet, the rest were dry.

Not sure if this means that some have worn nozzles that seep a bit, or if it means something else (?). But I thought it was interesting all the same…

 

[BMWTurboDzl]

I'm sure @Trav will be able to answer.

 

[Trav]

Pulled the five injectors from my Mercedes OM602.96 2.5L turbo diesel. The car has 228k mikes and runs and drives beautifully. It has a few weak glow plugs and starts easily with no help.

That said, experience tells the community that Injectors start to unbalance In terms of pop pressure around 100-150k, and the atomization tends to degrade around 150k, making it prudent to swap nozzles. Experience shows that higher mileage Bosch nozzles wear to produce more of a stream than a mist. Since I don’t have history on the injectors, and needed to pull the intake anyway to do glow plugs, I figured it was time.

I pulled them, and found that two were wet, the rest were dry.

View attachment 104022View attachment 104023View attachment 104024View attachment 104025View attachment 104026
Not sure if this means that some have worn nozzles that seep a bit, or if it means something else (?). But I thought it was interesting all the same…

View attachment 104028

Those 2 are definitely leaking/weeping fuel probably due to wear, at over 200K thay have done their job and want to retire. Bosch does remans for those that are okay and about $45-$70 ea depending on the model, just replace them all. What year and model is this.

 

[JHZR2]

Those 2 are definitely leaking/weeping fuel probably due to wear, at over 200K thay have done their job and want to retire. Bosch does remans for those that are okay and about $45-$70 ea depending on the model, just replace them all. What year and model is this.

1991 300D w124 OM602.96

It’s interesting. When I pulled the hard lines, the dry ones had fuel sitting in the threaded area. The wet ones didn’t.

Some theorize that injector leakage and poor spray contribute to wash down of the cylinder walls, and premature wear. Makes sense…

 

[Trav]

That is true along with increased emissions, smoke, nailing, etc. The fact the lines were dry proves they are leaking. The others are not far behind.
Sorry the price has gone up to $79 since I got some for a 240D.

https://www.autohausaz.com/pn/0986430247

 

[JHZR2]

That is true along with increased emissions, smoke, nailing, etc. The fact the lines were dry proves they are leaking. The others are not far behind.
Sorry the price has gone up to $79 since I got some for a 240D.

https://www.autohausaz.com/pn/0986430247

The car runs clean and smooth, but point taken.

Bosch now uses parts (nozzles) from India that are poor quality. I can get five refurbished, pop tested and balanced by greazzer over on the Peach Parts MercedesShop forum for $110. I do have new monark nozzles coming from Germany in case.

 

[Trav]

It is a shame that Bosch has gone down that road, the ones I have bought from Bosch have all been done in Germany but that was some years ago.
$110 is not bad at all if they run well.

 

[CleanSump]

$110 for a set of 5 balanced from greazzer is good. Haven't been to Peachparts forum in years.
For my 92 2.5 Turbo I tried the India nozzles and promptly replaced them with German. Didn't like the Monarch (Italian?) though. They were louder than the originals.
Went to 348k miles when I sold it running well. I rebuilt mine every 90k miles. Never had wet ones. I think I've still got the old pop tester in the attic. The 2008 has piezo, not mechanical injection. So no rebuilding if I need a set.
I miss the 2.5 for the simplicity. Easy to do the timing chain, time the pump, and convert the turbo to vacuum.
Miss the simple intake crossover pipe too.

 

[JHZR2]

$110 for a set of 5 balanced from greazzer is good. Haven't been to Peachparts forum in years.
For my 92 2.5 Turbo I tried the India nozzles and promptly replaced them with German. Didn't like the Monarch (Italian?) though. They were louder than the originals.
Went to 348k miles when I sold it running well. I rebuilt mine every 90k miles. Never had wet ones. I think I've still got the old pop tester in the attic. The 2008 has piezo, not mechanical injection. So no rebuilding if I need a set.
I miss the 2.5 for the simplicity. Easy to do the timing chain, time the pump, and convert the turbo to vacuum.
Miss the simple intake crossover pipe too.

Monark is German. Bozio is Italian, though I don’t know if they went out of business, changed their name to Firad, or what…

 

[CleanSump]

Monark is German. Bozio is Italian, though I don’t know if they went out of business, changed their name to Firad, or what…

Thanks. I've lost track and don't remember. It was long enough ago that it's probably irrelevant now anyway.

 

[JHZR2]

Got my injectors back. With Monark 314 injectors.