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Burning oil, Loss of oil pressure, oil in hull of engine compartment

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lazydaze

New member
1987 Crusader 454 Starboard Engine

Was on the way back to the marina and all of a sudden lots of blue smoke, essentially no oil pressure and found oil in the hull of the engine compartment. It's hard to tell exactly where the oil is coming from but it looks like the head gasket. I've seen posts saying that's impossible and that most oil leaks come from the valve cover. This seemed like a sudden significant failure with lots of smoke, immediate loss of oil pressure and oil coming out of engine. There is oil at head gasket, manifold and even at dipstick but it sprayed so hard to tell for sure exactly where. Engine temperature did not rise and I don't see antifreeze in the oil. The engine runs fine and starts fine but is blowing blue smoke. Before I go tearing it down, because I can't afford for someone else to do it, I was hoping for some advice.

Any help would be greatly appreciated.
 
UPDATE: So i ran the engine back at the dock the next day when it was a bit lighter out. It actually looks like the oil is coming from the exhaust manifold. I've seen some people suggest anywhere from just a manifold gasket, to piston rings, burnt pistons, to full engine rebuild.

Any suggestions? How do I tell which way to go?


lazydaze said:
1987 Crusader 454 Starboard Engine

Was on the way back to the marina and all of a sudden lots of blue smoke, essentially no oil pressure and found oil in the hull of the engine compartment. It's hard to tell exactly where the oil is coming from but it looks like the head gasket. I've seen posts saying that's impossible and that most oil leaks come from the valve cover. This seemed like a sudden significant failure with lots of smoke, immediate loss of oil pressure and oil coming out of engine. There is oil at head gasket, manifold and even at dipstick but it sprayed so hard to tell for sure exactly where. Engine temperature did not rise and I don't see antifreeze in the oil. The engine runs fine and starts fine but is blowing blue smoke. Before I go tearing it down, because I can't afford for someone else to do it, I was hoping for some advice.

Any help would be greatly appreciated.
Click to expand...
 
UPDATE 2: Took off exhaust manifold found oil in exhaust port of second cylinder from front of boat. Guess I need to take off head? So rings? Piston?



lazydaze said:
UPDATE: So i ran the engine back at the dock the next day when it was a bit lighter out. It actually looks like the oil is coming from the exhaust manifold. I've seen some people suggest anywhere from just a manifold gasket, to piston rings, burnt pistons, to full engine rebuild.

Any suggestions? How do I tell which way to go?
Click to expand...
 
UPDATE 3: Spark plug below the exhaust manifold port that is oily looks clean and shiny no apparent fouling on the plug. Does this mean bad valve? Really don't want to take head off if it's the valve or seat. How do I know what the issue is? Help?



lazydaze said:
UPDATE 2: Took off exhaust manifold found oil in exhaust port of second cylinder from front of boat. Guess I need to take off head? So rings? Piston?
Click to expand...
 
Sudden loss of oil pressure with oil sprayed around the engine compartment suggests a serious leak in the pressurized oil system. Look at your engine layout but typically the only places the pressurized system comes out of the engine are the hoses and fittings that take oil to the oil cooler and/or the remote oil filter. If you spring a bad enough leak there (failed hose or fitting) you could see this result. Any other place leaking in the pressurized system will not leak externally. Most likely cause of low oil pressure would be a failing pump or worn bearings, but these do not cause external leaks. I would fill it with oil and get my head down there (with glasses) while someone fires it up. I once saw it happen in a car when the oil filter got dinged and leaked bad so it could be easy. The hoses have big fittings (around an inch) and depending upon your access can be easy or very hard to get to.


Head gaskets generally do not leak oil externally and do not restrain pressurized oil. The other usual suspects (pan gasket, intake manifold gaskets, rocker arm cover gasket, etc.) also do not contain pressurized oil so they seep and drip but do not spray (unless the fan is involved). However, if left alone for a while it is amazing how far the oil can travel.So you might have had a slow leak followed by a catastrophic event.


Blue smoke in the engine compartment is all that oil burning off on the exhaust manifold. Blue smoke in the exhaust (which I think you mean) is oil getting into the combustion/exhaust via valve stem, piston ring or holed piston. The worst case is that the first leak (whether fast or slow) caused the low oil pressure and the engine did not shut down and serious damage was done (such as spun bearings) which led to other issues which led to the blue smoke. Some of the more experienced guys (who do this for a living) may have some other ideas. I would start with a compression check, after I found and corrected the oil leak.

Good luck.
 
UPDATE 4: Took the head off and there is a hole in one of the pistons. I'm going to drop the oil pan, unbolt it from cam and try and pull and replace it.

questions:

1 - What causes that to happen? lean mixture?
2- While I have the head off should I replace it or get it machined?
3 - What else should I do now that I have it torn down?

Thanks
 
Usually, gas starvation (often from too restrictive a filter before the fuel pump). Sticking anti-siphon valves are another common cause.

Jeff
 
lazydaze said:
UPDATE 4: Took the head off and there is a hole in one of the pistons. I'm going to drop the oil pan, unbolt it from cam and try and pull and replace it.

questions:

1 - What causes that to happen? lean mixture?
2- While I have the head off should I replace it or get it machined?
3 - What else should I do now that I have it torn down?

Thanks
Click to expand...

1987 and heads original? Check for warpage with a straitedge, and put in new seals, check the exhaust valves for recession; basically, take it to a good head rebuilder. Also easy to check for bore taper with the head off. If > 8 thou, then consider a bore job if you intend to run the engine for years to come. Install only one new piston in a high time engine is unusual. Can you actually drop the pan enough to get at the rod bolts, and then get a torque wrench back on it for reassembly? Does the cylinder ridge catch a fingernail?
 
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