8.1 Horizon Now Leaking Oil

[Jimmy Buoy]

Started seeing some engine oil in the bilge over the last month - port side. Was bone dry prior. Not a huge leak, maybe 1/2 pint/season.

Tracked it down to an area on the front of the engine, just below the crank pulley. Oil is visible in the gap just above the oil pan at the center line of the engine. As it escapes from the gap, it runs down the vertical front of the oil pan, then curls underneath and drips from the lowest point (the dipstick connector).

My first thought was an oil pan gasket leak, but I'm starting to wonder if it might be a seal for the crank (item #10 on diagram). Any ideas?? :huh:

Here's a link to the 8.1's diagram
http://www.perfprotech.com/store/as...kshaft-Oil-Pump-and-Front-Cover,7460-110.aspx

I just hate a dirty oily bilge!!:smt013

 

[fc3]

Could be that. Could be the timing case cover. Merc paints the engines fully assembled. I forget if there's a space between the circulating pump and the timing case cover. If there is, the cover is unpainted mild steel and could have rusted though causing your oil leak. I've seen this on GM small blocks. I had that problem on the previous boat. Typical half-assed Mercury approach to manufacturing. Have not had a similar problem with the big blocks, but I forgot if the cover was painted. I should remember, but I don't. I had the damned port engine partly disassembled last year.

 

[Jimmy Buoy]

Thanks for the quick reply and new ideas. Since the boat is going into heated storage next week, I'll probably start by draining the coolant (it's due anyway) and start removing the water pump, pulley, and timing case cover to see what's going on there.

I hope it's not the oil pan seal since it would most likely be impossible to change unless the engine is removed (in which case I'd just put up with the leak for a while), but since the pan is constructed of cast aluminum it should not have a rust/leak issue.

Thanks again. Any others ideas?