Diesel in Oil on Massey 3650

Calvin Otte · Apr 19, 2009

I have diesel in my crankcase oil. Any ideas on where it would be coming from? Some of the comments on older and smaller models indicate a leak in the diaphragm of the lift pump, but the manuals do not show a diaphragm on the lift pump. The manuals do show a seal on the injector pump that I sort of suspect. Where do I start to look?

Jeff Z. · Apr 19, 2009

I would start with the injector pump.

jogl · Apr 19, 2009

If the lift pump is the typical mechanically operated type (that is screwed on to the block and is driven by a lobe on the cam shaft) I would start with the lift pump. It is usually much easier and / or cheaper than working on injection pumps.

Of the four fuel in oil situations that I have dealt with three were lift pumps and one was the injection pump. Two of the fuel in oil situations mentioned were on Perkins 354's. The one with the bad injection pump was the NA motor in our 550 combine.

The other possibility that I have heard of is a bad injector dripping fuel into a cylinder. The fuel then washes down the cylinder walls into the crankcase. If it were an injector I would suspect that you would have a noticeable miss or power loss.

Good Day,
JP.

chuck41 · Apr 19, 2009

I am not certain of the 3650 but on most MF diesels I would start with the lift pump. If it
is set up as I believe, you can leave the lines
hooked up and unbolt pump and see if it drips any
overnite. Chuck

Anonymous-0 · Apr 19, 2009

lift pump is most likely your problem

Diesel in Oil on Massey 3650

Calvin Otte

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Jeff Z.

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jogl

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chuck41

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Anonymous-0

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