Diesel in injector pump oil

[DeliveryCaptain]

I’m doing the first complete servicing of my port Lehman 120 and when I drained the injector pump, the amount of oil that came out was more than it should have been and it smelled like diesel. The engine runs fine but I’m wondering if this is normal or a sign the pump needs repair.

 

[Max1]

It depends on your oil change interval. I try to do mine every 50 hours. first time I changed it it was like yours, but with frequent, on time oil changes, I've noticed that there's a lot less diesel in my injector oil Reservoir.
If you change yours on time, and you still get a lot of diesel in the reservoir, it probably means there's some wear in your injector pumps.

 

[Comodave]

The factory recommended time was 50 hours. You can ruin the pump with diluted oil. Bob Smith said to start out at 50 and gradually extend the time until you start to see dilution, then back off a bit. Every engine may be a bit different. One guy in the seminar had 2 120s. He said that one had to be done at 50 and the other one he could wait until 100 hours.

 

[DeliveryCaptain]

Thanks Max1 and Comodave, This gives me hope that the pump just needed an oil change. Our boat has seen a lot of deferred maintenance prior and I doubt the injector oil was changed frequently.

 

[READY]

If you get more than 50 hours without much dilution you should be ok. Otherwise it could be an indicator you need a rebuild. If so reach out to me as I have 2 professionally rebuilt spares. I could also share my source if you want to go direct.

 

[DeliveryCaptain]

If you get more than 50 hours without much dilution you should be ok. Otherwise it could be an indicator you need a rebuild. If so reach out to me as I have 2 professionally rebuilt spares. I could also share my source if you want to go direct.

Good to know. Thanks!

 

[Comodave]

Thanks Max1 and Comodave, This gives me hope that the pump just needed an oil change. Our boat has seen a lot of deferred maintenance prior and I doubt the injector oil was changed frequently.

No problem. I took Bob Smith’s last seminar before he passed away. Wow, he was an awesome source for knowledge. But his son Brian , has taken over American Diesel and he literally grew up with Lehman engines. So he is the guru now.

 

[DeliveryCaptain]

I spoke to Brian on the phone a while back. Very helpful. I buy all my engine parts from him.

 

[rgano]

I put petcocks in the bottom drains of the injector pump sumps on my two FL120s. After draining, I put exactly two cups of 30 wt oil in the sump after they were fully drained.

 

[socalrider]

Does the engine run well otherwise? I just had my port side 120 injector pump rebuilt due to the combination of diesel in the oil and worsening ability to control idle speed. Rebuild shop said it was pretty well cooked.