Oil Leak(s) Just got WORSE

[montenido]

Hi all,
I have a Perkins 4-154 with several thousand hours on it. It starts immediately and runs really well. However, I started noticing some oil in my bilge a while back and I have been trying to trace the source ever since. After reading some of the threads here, I recognize that it is quite normal for a Perkins to leak some oil.
Well, after all my poking around and cleaning of various areas to try to find the oil leak, I decided to put a drain pan under the rear main seal area with some absorbant pads. I went out and motored for a couple of hours with no problems. When I checked the drain pan a day or two later there was at least an inch of oil in it (10" square pan). Now that is certainly a new development
That seems like a lot of oil to me, and it seems like a lot if it is coming from the rear main seal. Maybe it has fully failed? I also have a built in drain hose that attaches to the oil pan in the same general area, and I am really hoping that this old hose has sprung a leak. I will try to check it out again tomorrow, but access is really difficult to get any kind of eyeball on the situation. I might check out one of the small fiber-optic camera tools sold at Harbor freight. It might help me see underneath the engine better.

As always, I am open to suggestions, and I value all of your input.

Cheers, Bill

[bombardero]

if the oil is not lost by any engine gasket is most likely that it's the snap ring that is on the outside of the crankshaft when the engine is cold when the engine lost acite heat dilates the piece and stop losing

[sww914]

The fiber optic tool is really cool and could be very useful on a boat but a magnet on a stick and a good flashlight will get the job done.
My Perkins is pretty easy to remove, if I had to replace the rear main seal I would just pull the engine and do the front, rear, and oil pan seals all at once.
At this stage I suspect that the oil hose that you mentioned is a more likely culprit if there's been a large increase in the amount of oil leaking all at once.
How does the dipstick compare to your previous experience?

[montenido]

Thanks for the info. So far, the motor does not leak when cold, and does not show any change in level on the dipstick. As far as pulling the engine, Man, I don't know. I will see if I can change the seal in place, then go to plan B if needed. Once pulled, the engine would have to go home with me, and I don't think that is wise .

I did buy and use the fiber-optic camera and it is a really cool tool, and was even on sale ($90). Still no obvious location for the leak, but it does first appear at the bottom of the bell housing, which would be consistent with a main seal.

Cheers, Bill