91' Merc 150 oil reservoir leak= strange

[verojoe27]

Went to start it up after sitting for the winter and it started right up. But the oil reservoir on the engine leaked out of thru the top cap that includes the low oil sensor. I took the cap off and retightened it, but it still leaked when the engine was running. Both oil reservoirs are filled with oil and the top is on tight on the remote oil reservoir too. The oil that leaks comes out of the small engine tank reservoir at a steady rate. I thought the low oil sensor in the cap might be stuck at the open position and that the oil pump doesn't know that the resevoir is already filled. Any thoughts would be helpful and apprecaited. Thanks, Joe.

 

[rodbolt]

Re: 91' Merc 150 oil reservoir leak= strange

not that strange. the cap most likly has craked. common problem. expensive but common. yet another example of engineering ineptitude <br />but do double check the gasket but odds are the cap cracked

 

[verojoe27]

Re: 91' Merc 150 oil reservoir leak= strange

I checked the cap and it is not cracked. The oil is leaking out between the threads on the reservoir tank and the threads of the gas cap. What makes the oil pump stop pumping oil when the reservoir on the engine is full? Any comments would be appreciated. Thanks, Joe.

 

[rodbolt]

Re: 91' Merc 150 oil reservoir leak= strange

hello<br /> its a pressure operated system. the engine pressurizes the remote tank and the pressure forces oil to the engine tank. either the gasket on the cap is missing or damaged or the cap is cracked. there is no pump for movinmg oil between the tanks. and oneday the check valve will fail at the fuel pump and you will have 3 carbs with pure oil in them . but check the gasket on the cap and the area around it carefully for cracks. its common.

 

[DHPMARINE]

Re: 91' Merc 150 oil reservoir leak= strange

Could also be stripped threads I suppose ....<br />But as long as air can escape the top of the motor resevoir, oil will also follow it.<br /><br />DHP

 

[verojoe27]

Re: 91' Merc 150 oil reservoir leak= strange

Thanks for the comments. I will try a new gasket in the reservoir cap if i can find one. If not, I will have to spend the $40 for a new cap. Thanks for the comments, Joe.

 

[imported_scott_m]

Re: 91' Merc 150 oil reservoir leak= strange

verojoe...you might want to call up Brydes marine over in St. Pete. I had to change my cap (same symptoms until it finally came apart). I think it was 22 dollars.

 

[gss036]

Re: 91' Merc 150 oil reservoir leak= strange

The crack will be at the very top and will only spread around about 1/2 of the cap. I on my 3rd one now. Very common problem .If your check/relief valve is not working your remote tank will bulge up from the excess pressure.