Onan MDKAL Injector Leak?

[Matt Vasey]

This is a 2001ish Onan Cummins MDKAL generator, with 440 hours.  I have been seeing diesel in the pan (perhaps 1 table spoon per hour) the last few weeks and today worked to track it down.  I found diesel leaking from the injector – not exactly clear where (see the picture).  There is a noticable amount of red dyed diesel at the base and discoloration on the injector compared to the others.  This runs down the side, and pools in the pan below.

Seems that this could be bad seals, or perhaps a failed injector.  Any thoughts?

Topic

[Tony Athens]

Hope it worked..

 

Fuel dilution:  Do you run the generator at very low loads for hours on end, like less than 10-30% (or less)  of the rating ?  If so,  that will do it. If this is the case, just change the oil more often if it worries you.

 

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Matt Vasey

[Matt Vasey]

Thanks to Tony, I got in there to address the injector issue, and noticed a drip of diesel on this fitting n the picture.  I cleaned the whole area with solvent, then started and loaded the generator.  I was able to visualize the leak happening, coming from the fuel return coupling into the brass fitting.  I losensed and tightened, and seems that the leak is gone.  I further secured the rubber section of the return line so it cannot move and break the seal again.

This does not address the fuel in oil issue, but I will test the oil again and see if this continues to be an issue.

 

Thanks, Matt

[Matt Vasey]

Thanks Tony – this is super helpful!

Thanks Tony!

This is super helpful – I was wondering if this was either 1. remove and replace crush washers and O ring or 2. pull the injector and get it rebuilt

Based on your response I will try the losen/retighten approach to see I i can re seat the exising washer and stop the leak.

Thanks Again!

 

 

[Tony Athens]

Looks to me like you need two (maybe 3)  wrenches and full  understanding of what to do–Loosen & tighten the sealing nuts/glands – two to 3 times , and then a final tightening to reseal the sealing services..

If you are not “hands-on” the you need to get a qualified “wrench” that understands what is really going on and to do.. You do not need,  or really want an “ONAN” tech, you need the good all -around diesel mechanic.

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Matt Vasey

[Matt Vasey]

Oil Report for Onan shows Fuel Dilution

Photo attached of Oil report summary – another clue…

[Author]

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