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Water in my manifolds small block v8! Help!


Water in my manifolds small block v8! Help!

Old 08-09-2015, 03:50 PM
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Originally Posted by avalonandl View Post
Could gas be getting in from fuel pump?
Some mechanical fuel pumps just have a rubber diaphram keeping the fuel out of the crank, so yes it is possible on some engines, not sure about this one though.
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Old 08-09-2015, 04:22 PM
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That's great there was no water after all.

Yes , as long as there was no obvious "chocolate milkshake" look to the oil after cranking , it is very unlikely there was water in it. But a substantially-overfilled crankcase will quickly badly aerate for interaction with the pistons and rods. When that happens foamy oil expands and some can be pushed out the breather hoses and at the same time the oil pump essentially becomes air bound and oil pressure drops to 0. This would also act like detergent action to loosen old contaminates and sludge to make newer oil black.

FWIW, my small block marine GM's with remote filter (hoses) take 6 to 61/2 qts after full emptying by built-in pump from the pan drain fitting.

So I'm guessing there was a bit too much oil to begin with and each time a definitive oil line was not seen on the proper area of the stick, more oil was added until the aeration critical level was reached and surpassed. You probably do this, but due to the difficulty of reading clean oil on the stick, I recommend pulling the dipstick the 1st time and ignore the reading , wipe clean , and FULLY reinsert. Then quickly pull it again and roll it on a clean paper towel or cloth to see where the absorbed oil line compares to the dipstick markings. I'd do all that each time you check level for a pretty accurate readings, and remember to insert the stick in the same orientation each time .

However, due to the excessively low compression numbers in 2 of the cylinders combined with high oil levels, I wonder if rings or cylinder walls could be bad allowing liquid gas to enter the crankcase and over pressurize the crankcase. Did the pumped-out oil look diluted or smell gassy?

Does this engine have a mechanical fuel pump, and if so have you checked the sight tube from pump to carb for fuel in case the pump diaphragm is leaking? If that was shooting excess gas in the cylinders the rings would be oil starved.

And since you mentioned you can usually get the engine to start by simply pulling off the flame arrestor, is the arrestor in need of a good cleaning with Dawn or carb cleaner?
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Old 08-09-2015, 04:42 PM
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Sounds like someone forgot to drain old oil before adding new. You may have dodged a bullet.
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Old 08-09-2015, 06:25 PM
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Yes, mechanical fuel pump. No gas in sight tube. The black liquid was very runny, not the normal oil viscosity.
I may have caused this whole mess myself. In the spring I ran the engine until it was at normal temp. Shut it down and used my extractor to pull out about 5.5 quarts. Thinking maybe I lost some, burned some. Now I think maybe there was a lot more oil in that pan! My engine calls for 6 quarts. I hope I dodged a bullet!
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Old 08-09-2015, 08:24 PM
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Dipstick extractors always leave some residual oil in the pan. So I'd venture pulling out 5.5 qts was doing pretty well. But never put in more than you took out if level was previously correct. That is, it helps to pump out into incrementally- ( by Qt) marked containers.
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