Oil leak without engine running?? Any ideas?

Studini
Tin star
Posts: 26
Joined: Wed Oct 24, 2018 8:00 pm

Oil leak without engine running?? Any ideas?

Postby Studini » Sat Feb 16, 2019 11:01 am

Went down to check on the boat today, I just bought it in the fall so haven't ran it much. Previous owner told me he thought the leak was a valve cover. I changed oil before winterizing. This is the starboard 360 which he had rebuilt and has about 50 hours on it. I've got oil sitting in the bilge?? Where would it be leaking from just sitting there without being ran in 3 months?? Ugh... Help..
88 32’ Fisherman
“Get Busy Livin”
Twin 360’s
Fairport Harbor, Ohio

liquidplummer
Member
Posts: 12
Joined: Mon Jul 14, 2014 9:15 pm

Re: Oil leak without engine running?? Any ideas?

Postby liquidplummer » Sat Feb 16, 2019 12:56 pm

Check the front drain on the oil pan sump, my boat has a small ball valve installed, not sure if this was original equipment or added later. Check your oil filter for leakage. Oil could also be from a cooling line from the velvet drive transmission, or the trim tab reservoir.
Silver Queen St Louis Mo
1982 37 ft flybridge sedan twin 360 chryslers 1.91 velvet drives

javalin390
Royal Aluminum Star
Posts: 286
Joined: Sat Jan 10, 2015 7:14 pm
Contact:

Re: Oil leak without engine running?? Any ideas?

Postby javalin390 » Sat Feb 16, 2019 1:32 pm

There are several factors, here are several scenarios. Crankcase may be overfilled and leaking past the rear of the oil pan. There are two different oil pans on Chryslers, one is the standard stamped steel pan, also used on Dodge trucks (not sure of the pan's capacity) and the cast aluminum pan (the two have different capacities). The engine sit tilted to the rear to facilitate the angle for the prop shaft to go out the bottom. If the little half moon part of the oil pan gasket, in the back of the engine, is fully submerged in oil while she sits over the winter, and is old and dry rotted, she's going to leak. Another possibility is the oil filter mount. After performing your last oil change, firing up the engine, filling the oil filter, before hauling her out for the winter, all seemed well. With the filter full and sitting, the large round gasket for the oil filter cast aluminum filter adapter, will leak. Mine did this. This thin cardboard gasket is a weak point and after many years, dry rots. This gasket, Chrysler #3671314 or FelPro #70522, along with its adapter (Chrysler #2951996) is primarily used on inboards and 4X4 Dodge trucks. Marine I/O and car engines, the oil filter screwed directly to the block. Obviously the oil pan gasket is a big job that no one wants to tackle OR pay to have done. The oil filter adapter gasket, on the other hand is cheap, and is easy for most M owners to handle. Both of these leaks will leave enough oil in the bilge to cause concern/to be noticed. Wipe your finger under the filter adapter and see if its wet, if so, you may be lucky. If it's the pan gasket, you could try my redneck idea and just fill the oil until she's about a half quart low. Anything to keep oil out of the bilge !
Jim Elias
1974 37' SedanFlybridge
Twin 360 Chryslers.
Marblehead, Ohio