JD 6900 Diesel getting into the engine oil

[Sebastian77]

Our old faithful 6900 (14000 hours) is gaining oil level in the engine, doesn't look like cooling fluid because the oil has no discoloration, just much thinner than it should be so assuming it has to be diesel getting in.

Am I right in thinking the only point of entry could be fuel injection pump?

 

[Cowabunga]

It could be the injector pump front seal but it could be a leaking injector or cold start unit. Although the pump is most likely, the others are simpler to test for, so maybe do so first. I would have thought that a leaky injector would result in white smoke, so a quick look at a cold start may be sufficient to eliminate it or even both, leaving the pump.

 

[Sebastian77]

It had new injectors last summer to sort out a obvious misfire on one of them, so just did all. That's not to say one couldn't have gone faulty of course, but it's not running rough. When you say cold start unit what exactly are you referring to?

 

[Cowabunga]

It had new injectors last summer to sort out a obvious misfire on one of them, so just did all. That's not to say one couldn't have gone faulty of course, but it's not running rough. When you say cold start unit what exactly are you referring to?

I’m not sure whether Deere fitted thermostart or grid heater units to those models. Either will be in the inlet manifold. If the thermostart [not thermostat] unit leaks the diesel could run down past the rings into the oil. Not sure whether this is an actual issue with low mounted fuel tanks but it could be on older tractors with tanks above the engine.

 

[Deerefarmer]

Injection pump needs sent to pump shop

 

[R&D]

As above, we had this happen to ours.
Don’t know where you are in Nottingham, but we sent ours to County Diesel in Syston Leicestershire.

 

[Barleycorn]

Blimey our 2030s/2130s used to do this in the seventies. Always well over the dipstick on oil changes.