4.3 mercruiser small oil leak above starter somewhere

[iskiglass]

My 1999 Campion with 4.3 Mercruiser has a recent replacement block that has a slow oil leak above the starter somewhere. Thinking it is likely the oil pressure sending unit or the valve cover gasket. Looking for general advice please.

If I do the valve cover would you recommend I spray some specific brand of copper spray on one side or both or coat the gasket with a different sealant? Gasket I got from GM dealer is rubber.

Will I need to remove the exhaust to adjust or replace the oil sending unit which is apparently just below it? WHat else could be leaking about a tablespoon an hour from that area, the head gasket?

Other info: oil is dripping onto the one year old starter which now throws sparks and clicks and so far will start if I tap with a hammer. that whole side of the engine and compartment seems to have a coat of oil on it but not sure how its getting there.

Thank you so very much for your help. Summer is here and I need to fix this beast! Boat is in the water and I'd like to fix it without taking it out... Was running good

 

[Bondo]

Re: 4.3 mercruiser small oil leak above starter somewhere

My 1999 Campion with 4.3 Mercruiser has a recent replacement block that has a slow oil leak above the starter somewhere. Thinking it is likely the oil pressure sending unit or the valve cover gasket. Looking for general advice please.

If I do the valve cover would you recommend I spray some specific brand of copper spray on one side or both or coat the gasket with a different sealant? Gasket I got from GM dealer is rubber.

Will I need to remove the exhaust to adjust or replace the oil sending unit which is apparently just below it? WHat else could be leaking about a tablespoon an hour from that area, the head gasket?

Other info: oil is dripping onto the one year old starter which now throws sparks and clicks and so far will start if I tap with a hammer. that whole side of the engine and compartment seems to have a coat of oil on it but not sure how its getting there.

Thank you so very much for your help. Summer is here and I need to fix this beast! Boat is in the water and I'd like to fix it without taking it out... Was running good

Ayuh,.... Rubber gaskets don't need sealant,...

The O/P sender screws in Next to the intake, not under it, it's close...

I'd sooner think the end piece of the Intake gasket set is where the leak is,...
They can be a Real bugger,...

I don't even use 'em, I toss 'em,...
I run a nice bead of silicone across the block flange, let it skin over, then plant the intake down onto it,...
Clean up any silly-seal that smooges out, 'n torque 'er down,...

 

[iskiglass]

Re: 4.3 mercruiser small oil leak above starter somewhere

Thanks for the reply Bond-O. I will consider the intake gasket. Any other good advice out there on finding the source of the leak?

 

[Don S]

Re: 4.3 mercruiser small oil leak above starter somewhere

You can also clean up the mess, spray some talcum powder around the suspected areas and go for a ride. The tracks of the leak will be obvious in the powder.

 

[iskiglass]

Re: 4.3 mercruiser small oil leak above starter somewhere

Thanks Bubba and Don S. I am thinking since the boat has sat for about two weeks without running, most of the oil has dripped down and off the engine. SO should clean up easy enough, maybe just use my simple green and paper towels. Now, to see if I can find talcom powder in some cabinet somewhere... or off to the store for talcom or dye. At leas talcom has other uses...

Thank you!

 

[Don S]

Re: 4.3 mercruiser small oil leak above starter somewhere

Get the spay talc, it sticks to the engine better.