Oil leak on Mercruiser 165 Inline 6

[marvinjansen]

Well, ran about 30 miles today running Lake Tuscaloosa from south to north. Ran good. Problem is oil leaking from engine on the exhaust manifold side, pooling in the indents on the manifold and running down. I replaced the valve cover gasket earlier and thot that would fix it but it didn't. It seems the oil may be coming from the head bolts. Haven't tried to retorque the head. Any suggestions?

 

[Bondo]

Re: Oil leak on Mercruiser 165 Inline 6

Ayuh,... Headbolts don't hold back oil,...

I'd think the valve cover, or it's gasket...
Is it blowin' out the vent,..??

 

[Silvertip]

Re: Oil leak on Mercruiser 165 Inline 6

Or you overtorqued the cover screws to the point where the cover is distorted around the holes which immediately screws up an otherwise good gasket.

 

[vxtech]

Re: Oil leak on Mercruiser 165 Inline 6

apply rtv to valve cover then apply gasket while valve cover is upside down insert cover bolts through gasket and cover for hole alignment, let rtv cure so it glues to valve cover, once glued remove bolts flip cover over and install on motor, i don't recommend rtv on head unless your completely confident in lifter lash adjustment - you may need new gasket to complete if old gasket is deformed or torn- don't over tighten

 

[Don S]

Re: Oil leak on Mercruiser 165 Inline 6

To fix a leak, you first have to locate exactly where the leak is coming from. Clean everything up around the head and valve cover with engine cleaner. Then, since it's a black engine and hard to see leaks, spray some talcum power on it. then run it, you will see exactly where the leak is coming from, and will know what to fix.

 

[marvinjansen]

Re: Oil leak on Mercruiser 165 Inline 6

I will try to clean n talc powder.
It does have some blow by from the vent to the air cleaner.
I used a rubber gasket instead of a cork one, and used 3m weather strip gasket to VC and I think Permatex black or some kind of gasket maker. I snugged the bolts then tightened a little more after the gasket maker cured. Isn't leaking on the spark plug side, but on the exhaust and intake manifold side. May be the gasket but I have put on hundreds of them on vehicles successfully. We will see what the talc test shows. Thanks for the replies.

 

[marvinjansen]

Re: Oil leak on Mercruiser 165 Inline 6

Leak almost gone, put some form a gasket (avaition) on head and rubber gasket and only a small amount of oil from near the front manifold side bolt. Much better. Also, found out from previous owner that this is a replacement engine with only one season's use. Took out today for a nice ride.