Oil on engine

[tch]

Hopefully some one can help me with an oil problem. It seems I get a misting of oil all over my engine (3.0). I can clean it and in a few runs it is oily again. The oil level isn't dropping from what I've noticed but that will only be a matter of time. It is more of a nuisance at present but want to get this corrected. I tried running the engine with the cover off but cannot seem to find a source for the oil. You can imagine the mess in the bilge. Thanks for a good website.

 

[DJ]

Re: Oil on engine

Tlanier,<br /><br />It sounds as if your engines crankcase ventilation system is either:<br /><br />1. plugged.<br /><br />2. non existant.<br /><br />First, look at your flame arrestor. Is it clean? If not, clean it.<br /><br />Second, you may have a tube that runs from the valve cover to the carburetor or flame arrestor. Make sure that tube is free and open. Also, there may be a PCV valve in the valve cover that the tube conects to that is clogged. The tube and PCV valve can be cleaned with carb. cleaner-remove them for cleaning.

 

[Cobotr]

Re: Oil on engine

The problem is that there probably isn't a pcv valve. Check the hose that goes from the valve cover to the flame arrester. That hose probably doesn't have a pcv valve in it and the natural crankcase pressure is blowing the vapors up the tube to the arrester. The arrester is supposed to suck the vapors into the carb to be burned. Some end up elsewhere.<br /><br />You can fix it and never have to clean the arrester or engine again by: adding a pcv valve to the valve cover (use a 90 degree elbow style), then route new fuel resistant hose from the valve to the new vacuum port that you install into the intake manifold. There is a pipe plug on the intake manifold just to the rear of the carburator. Take the plug out and replace it with a vacuum fitting (available at any auto parts store). Again use a 90 degree fitting if available. You will need a longer hose than the original, so measure the distance. Connect the hose from the pcv valve to this port.<br /><br />What you have without the pcv is a draft crankcase ventilation. Same as cars used prior to 1966. They used to use a tube from the valve cover to the bottom of the engine and let the air that rushed past the tube suck the fumes out. After converting, you will have a positive crankcase ventilation system.

 

[tch]

Re: Oil on engine

Thanks for the info. I dedicated some time specifically for this and noticed, as was posted, below the tube from the top of the valve cover to the flame arrestor was blow out from the hose. I think the second suggestion would be the best path to correct the problem. Thanks again for a great site.

 

[flashback]

Re: Oil on engine

I would also check the level of oil in the power steering resevoir. if you spring a small leak in one of the hoses or the pump unit itself, it is very capable of slinging oil around.

 

[tch]

Re: Oil on engine

This boat doesn't have power steering. One thing I thought of when looking at the engine, What about all this oil getting sucked through the intake and into the combustion chambers? Would this have a long term detrimental effect or does the PCV valve keep that from happening?

 

[Cobotr]

Re: Oil on engine

All engines have a certain amount of blowby past the pistons. This blowby creates a pressure inside the crankcase area of the engine. The pcv allows the pressure to be vacated into the intake and burned. This is a very small amount of oil vapor, which creates no harm to the engine. <br /><br />Otherwise it is vapored toward the spark arrestor where it "hopefully" is sucked through the carb, but finds itself hazing the engine. Because at idle, you have little suction through the carb, but you are creating crankcase pressure. So vapors are coming at the arrestor but not sucked into the carb.