From where comes the bubbling crude?

[Jeepers]

Oil, that is. If i just putter around, no problem. If i run hard, offshore and back, i end up with at least a quart of oil under the port engine. Oil cooler? Leaky hose? Everything else looks good but its hard to find the origin because of the splashing that occurs when running. Inquiring minds want to know.

 

[AKBASSKING]

Valve cover gasket leaking. Could be a host of things. You will need a very bright flash light and ability to bend your body (tanke some butter with just in case!). simply trace the problem to its source. If you can't find it this way you will need some beer to have a friend help and run the tub so you can look. Just be carful of spinning parts and where you stick your fingers and loose cloths.

 

[Jeepers]

Top of motor is clean from oil pan up. Valve cover,gear cover,intake gasket, etc is clean. Pan shows no sign of leaky gasket. I was leaning toward oil cooler or hose since it only happens when i throttle up and oil pressure increases. Was hoping someone may have had a similar problem.
butter,thin slice,with my coffee. Old family thing.

 

[SCORPIO]

A rear main seal perhaps? Or a front crank seal? Thats alot of oil for a short run, so I would think you could see it while its happening. Have someone run the boat and take a look in the engine compartment while underway on plane.

 

[moparlvr4406]

put a UV dye in the oil and look with a black light
that's how we find mystery leaks in cars

http://www.thefind.com/cars/info-gasoline-engine-oil-uv-dye

 

[fwebster]

Here is a possible cause I've seen numerous times on 7.4's here in Florida. It usually occurs at about year 7 or 8 here, but with you in NJ, it could take longer. Mercruiser assembles the engines and installs the accessories and then they paint the engines. The circulating water pump on the 7.4 straddles the timing cover. Timing covers were not primes or painted so just the salt air will eventually rust them thru from the outside in. At low speeds, there isn't enough oil slinging around on the timing set to leak, but at speeds, oil will come out of the rust holes because oil is slinging about and because of crankcase pressure. THe oil runs down the timing cover behind the water pump and ends up dripping off the front of the engine or running around the crankshaft, making you think you have a pan or seal leak. The fix is a new timing cover, not expensive by itself, but you will replace both sides and both water pumps while you are into it.

Hope its that simple..............

 

[Bt Doctur]

oil filter has a double gasket/loose/over tightened
oil pressure sender rusted and leaking,usually just above filter
elec fuel pump switch usually same place the oil pressure sender mounts.

 

[Jeepers]

Thanks gentlemen. Back at boat in a couple of weeks. Good thoughts for me to investigate