Crazy Dipstick on Perkins 4-108

[Ondine36]

Last year I purchased a Cheoy Lee Luders 36 and I am only now turning my attention from re-coring her late, not lamented teak deck, to her engine. It reportedly ran strong prior to purchase, but I've only run it briefly on the hard since. I'm not a mechanic - so I started with the easy stuff. I checked the oil and, wow, the dipstick read way way off, almost 6 inches above its max mark. I wiped it again, checked again, made sure the dipstick's part # matched. So, I drained the oil - cold - from the pan's plug. Got 6.75 qts - the manual calls for 4.8 to 5.7. Seems overfilled but not crazy. Oil looks/smells healthy, does not appear to have fuel or coolant in it. So.... refill with fresh oil, and then wait for spring to pull boat's tarp, run engine and do a proper oil change. Relax - in other words - or dig into what could be a serious problem before it ruins my launch.

[Cheechako]

Maybe they filled it up for storage? I have heard of that.
or
Maybe it has issues and is "making oil" from fuel in the oil. It's pretty hard to tell really. Can you try putting some of the old oil in a jar and see if it separates?

[oldcal46skipper]

Did the oil smell like diesel fuel? Two common sources of fuel leaking into the oil pan on a 4.108;
1-Mechanical fuel pump diaphragm leaking. Remove it and carefully inspect. There are several sources for parts

2-The high pressure fuel injection pump can wear and allow fuel into the oil. Carefully index the pump and take it to a reputable FI pump rebuilder. The test device for FI Pumps costs over $20,000 USD, so be cautious

Up here in NW FL, we use Atmore Fuel Injection in Atmore, AL which is 50 miles from our shop in Pensacola, but worth the drive as they are competent.
We are removing a FI pump as we speak and will be taking up there this afternoon.



More details on request

[Compass790]

Originally Posted by Ondine36

Last year I purchased a Cheoy Lee Luders 36 and I am only now turning my attention from re-coring her late, not lamented teak deck, to her engine. It reportedly ran strong prior to purchase, but I've only run it briefly on the hard since. I'm not a mechanic - so I started with the easy stuff. I checked the oil and, wow, the dipstick read way way off, almost 6 inches above its max mark. I wiped it again, checked again, made sure the dipstick's part # matched. So, I drained the oil - cold - from the pan's plug. Got 6.75 qts - the manual calls for 4.8 to 5.7. Seems overfilled but not crazy. Oil looks/smells healthy, does not appear to have fuel or coolant in it. So.... refill with fresh oil, and then wait for spring to pull boat's tarp, run engine and do a proper oil change. Relax - in other words - or dig into what could be a serious problem before it ruins my launch.

Welcome to the forum Ondine,
If the oil doesnt seem bad I would do nothing at this stage as you can always pull the 2 pumps off later if it proves to be leaking diesel into the sump. Might be just a stuff up filling it if u r lucky.

On second thoughts I might check the lift pump diaphragm if thats easy to do.
You wont be risking catastrophic failure if you keep an eye on the oil level & check that its not rising & if so then do the steps that Old Cal46 said.

[Reefmagnet]

If the engine is inclined (as many are) and the dipstick is anywhere other than the centre of the sump then the correct oil level will read higher or lower on a standard dipstick when the engine is filled with the correct quantity of oil. This can catch the unwary out.

[bongo]

1) We have a Westerbeke 40-108, which is 90% Perkins 4-108. The manual has a few pages that were added at a later date. One is the dipstick was changed at some point, (late 70’s or early 80’s?). They actually have a life size print on the sheet, to compare it to. I don’t have access to it at this time, however.

2) Fuel oil dilution of lube oil cannot be removed by the lube oil purifiers, (centrifuges), on ships. The specific gravity is too close. Not sure if the diesel oil would ever stratify out of the lube oil.

3) Perhaps it was overfilled? Ours was by the PO. Never had a problem since.

4) The oil filter and oil galleries may have drained back to the sump.

5) If not these, then like Cal46 said.

Good Luck, Greg

[n5ama]

Originally Posted by Cheechako

Maybe they filled it up for storage? I have heard of that.
or
Maybe it has issues and is "making oil" from fuel in the oil. It's pretty hard to tell really. Can you try putting some of the old oil in a jar and see if it separates?

I don’t think you will see any separation between oil and any fuel such as diesel or gasoline. The only thing you might notice is a change in the viscosity if diluted a lot.

[Quadrille in JB]

Be very careful with high oil levels as you are at risk of a diesel runaway!
Once the oil gets high enough the fuel bypasses the rings and the engine goes to WOT. This is very scary and very dangerous.
We had this happen to us several months ago and we blocked the air intake to shut it down. Even then so much oil entered the cylinder that it blew the head gasket.