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1989, 502 Crusader still with water in oil!!

O

o2bboatn

Member
Had mechanic replace exhaust manifolds, risers on starboard engine after a leak caused bent push rods on #8 cyclinder. All checked out great after work completed; compression check, temps checked alll running fine. Ran boat to new dock location, 1 1/2 hours, temps 165, pressure 60 lbs. 2800/3200 rpms. Next time to boat checked oil, good color but showing about a 1/2 qt. high. Checked heat exchanger overflow tank, same level as always. Started enginge oil changer to draw down oil over level and found water! Pulled filter, more water! Sent oil sample= sea water. Called mechanic to repair! They pulled each exhaust manifold/riser off as a unit and bench checked for pressure and correct flow, all seemed fine. They theorized that the sea water was getting back into the engine from the exhaust cross over tube. They put longer connectors between risers and crossover (all original exhaust system, no problems over the last four years). This past weekend, I replaced the oil cooler, flushed oil and filter twice, and went out for a 30 minute trial run. Same situation, oil look 1/2 qt. over full on dip stick, filter loaded with sea water.

Where do we go from here? Any suggestions would be of great value.
 
Mystery! Just to clarify. It sounds like the first time you ran the boat 1 1/2 hours and then after letting it sit a day or more checked the oil level and found the water. After the attempted repairs and oil change you then did a 30 minute run. Did you check the oil level and find the water immediately or was it after again letting the boat sit for some time?
 
I assume the risers are FWCooled. If so, the only way sea water can get into the oil is if it blows back up the exhaust system.

Have you had to suddenly jump off plane recently? A sudden stop CAN do that.

Jeff
 
Thanks for the replies!

Cabojohn, the first check was several days later; thinking the problem was solved. The second check was immediately after sea trial, thinking it might be the oil cooler, NOT!


Fastjet, no/never sudden on/off plane or stops.

I guess it goes back to the yard! $$$$$$$$
 
Mystery! Something just does not add up. If the water got in the oil during running (as you believe in case #2), then I would think it is very unlikely it is salt water. When running the oil in the heat exchanger is under pressure so it can leak out, but water cannot leak in. The only other source of salt water (that I can think of) is from the elbows. If your replacement job was botched, sea water could drip down into the exhaust manifold, go though an open exhaust valve, into the cylinder, past the rings and into the crankcase. All that can (and does) happen, but not while the engine is running.

The only really viable route into the oil, while running, is water dripping into the oil galley under the intake manifold. This can happen if the intake gasket is compromised or the head is cracked, but the water will be coolant, not salt. Or possibly, a cracked block could leak directly into the oil pan, but again that is coolant, not salt.

Or maybe your engine has some seawater in some place around the engine that I have never heard of (or have forgotten). Or maybe it is not sea water that is in the oil. You might check again.

CaboJohn
 
CaboJohn,

Thanks for the thoughtful input! From what you say about the oil cooler/engine oil pressure, than it has to be the risers.

thanks again!!!
 
CaboJohn said:
Mystery! Something just does not add up. If the water got in the oil during running (as you believe in case #2), then I would think it is very unlikely it is salt water. When running the oil in the heat exchanger is under pressure so it can leak out, but water cannot leak in. The only other source of salt water (that I can think of) is from the elbows. If your replacement job was botched, sea water could drip down into the exhaust manifold, go though an open exhaust valve, into the cylinder, past the rings and into the crankcase. All that can (and does) happen, but not while the engine is running.

The only really viable route into the oil, while running, is water dripping into the oil galley under the intake manifold. This can happen if the intake gasket is compromised or the head is cracked, but the water will be coolant, not salt. Or possibly, a cracked block could leak directly into the oil pan, but again that is coolant, not salt.

Or maybe your engine has some seawater in some place around the engine that I have never heard of (or have forgotten). Or maybe it is not sea water that is in the oil. You might check again.

CaboJohn
Click to expand...

Oil in the heat exchanger? I assume you meant the oil cooler and not the heat exchanger. However a fellow boater at my marina did experience sea water in his oil via the oil cooler on his Merc 454 engine. He replaced the oil cooler and did several oil/filter changes to correct the problem. Isn't it possible for oil that is no longer under any pressure to leak into the water section of a cooler as things cool down?

Erich
 
@erich You are so right. I was thinking the "oil heat exchanger" which on boats is properly called the oil cooler. As for the a possible leak, when the motor is running oil pressure (40-60 psi) will insure that oil can get out into the raw water but raw water cannot get into the oil. But when the engine is shut down and oil pressure drops to zero, the raw water extends up to elbows, far above the level in the oil pan. So there is enough hydraulic pressure for the water to work its way into the oil in the oil cooler. Since this motor seemed to get water in the oil without any period of shutdown (and since he has already changed the cooler out), it does not seem that is the issue.

Of course the same logic says sea water does not get past a rapidly opening exhaust valve blowing out exhaust, so it can't get in that way either. So is it really sea water??
 
This Crusader 502 is the first generation model, it has a "U" tube oil cooler. Raw water flows down the one side of the "U" to cool the trainsmission oil and up the other side to cool the engine oil, then on to the engine heat exchanger. Will be reviewing the whole situation the weekend, hopefully I will find something!
 
Pressure tested the new "U" oil cooler, all is well. On to new thought/feeling. New cam installed last summer due to lobe deterioration (long story) and maybe the lift and duration are off. We are trying to locate the original lift and duration specification for a CCW 1989, 8.2L, Gen IV. model #81350 Crusader. This is a flat tappet lifter engine. If anyone knows where to look or who to contact for this information please let us know. I need to her back in on the high seas!!!!

Thanks!!
 
We all have been warned that a camshaft with too much overlap can suck salt water back though the exhaust valves. Maybe someone on the forum has had the experience and can comment on just what occurs. I would think, however, that it would lead to coughing, choking, missing and maybe hydraulic lock. What you describe is the oil pan slowly filling unnoticed with sea water during a run.

Are you absolutely positive the "water" you have found in the oil is seawater and not coolant? As discussed earlier it is easy for coolant to get in the oil while running but not easy for salt water.

In the second occurrence you described, are you absolutely sure the water got in while running, not before the run (but after the repair)? If you turned the engine over before the run and then let it sit with sea water in leaky elbows that could be when it drained down. See post #6. (Although it is hard to believe they would have that much water.) I don't think it could have happened after the run you described since the water was found in the oil filter.

So, if you think that could have happened let the engine sit for a day and then pull your plugs and turn over the engine and look for water spraying out of a cylinder (probably one or more of the ones right below the exit to the exhaust manifold). You can hang some paper towels down to be sure to find it if it sprays. It will spray for a half dozen of so revolutions before it is all out. What happens is water has drained down from the elbows and gotten caught is the spaces in the exhaust manifold that are next to some of the cylinders. If the exhaust valve is open (some are, some are not) the water will drain into the cylinder and then into the crankcase if your rings are in poor condition. When you turn it over with the plugs out after sitting awhile with leaky elbows, the small pool of water caught above the closed valves drops in to the cylinder as a slug and get sprayed out the open spark plug hole. No time to drain into the crankcase (just like when it is running).

CaboJohn
 
I have tried about 5 times today to download the pictures to send to this forum. Anyone have an email address or two I can send the pictures to. Thank you.
 
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