Excess oil????

[im_chad]

Well here is the background. I have an 03 LB7 with 180K. I have been running Amsoil full synthetic 15-40 since 50K.
I got the low oil pressure warning on the DIC. When I checked the dipstick it seemed to be too full. So I completed an oil change, I was shocked to find that I drained nearly 5 gallons of fluid out of the pan!?! It looked and smelled just like normal oil but the viscosity seemed really thin.
Where could the excess fluid have come from?

Thanks

[Mark Rinker]

Welcome aboard.

My guess is that your crankcase oil is being diluted with diesel fuel from one or more failed injectors, or a leaking fuel return line from one or more injectors, under the valve covers.

If you search these forums, you'll find this is a common malady with the LB7 engine family (2001-2004.5) and is usually remedied by replacing all 8 injectors.

Good news? The Duramax lives up to its name, I have yet to hear of anyone with cylinder scoring or bearing issues as a result of the diluted oil. That being said, I wouldn't continue to operate the truck until the problem is corrected.

Q: Any white smoke at idle in your exhaust?

[Kennedy]

I would agree. Time for a set of injectors and as always I recommend replacing all 8 supply lines as well.

[im_chad]

Thanks for the replies. I have been inquiring the forum for a few years and your experience and support has always been appreciated.

As for the white smoke, no; not at startup, cold, hot or idle.

A Big THANK YOU to you sirs!

[More Power]

Rough running, especially at lower engine speeds, usually accompanies an overfull crankcase. Crankshaft churning of the mixture interferes with engine balance.

Jim