:
- 4.
My oil has turned "milky". How can I troubleshoot to determine
how much water may have gotten into my oil, and what can be done
to remedy the situation?
Assuming that
you have been using detergent oil, which is normal for the Atomic
4, the detergent will emulsify (causing suds - like laundry detergent)
if even a small amount of water enters the crankcase. The emulsifying
process almost always creates the impression that there is more
water in the oil than is usually the case.
Whenever water does make it into the oil pan, particularly in small
amounts, we always recommend changing the oil at least two or three
times, or until all evidence of the water is removed. If the water
can be removed in this fashion and not return, we recommend that
you observe the oil for at least 10 or 20 hours of operation before
doing anything more serious. Each year, we hear of water intrusion
into the crankcase which never re-occurs after it is removed through
changing the oil multiple times.
The most common way that water gets into the crankcase is from engine
cooling water backing up within the exhaust system until it floods
back through the exhaust manifold. It then passes into, and through,
the combustion chambers, and down to the oil pan. This scenario
can be caused by simply over-cranking a hard starting engine (with
the raw water through-hull open) or from an internal failure of
the water lift muffler.
Sometimes, problems within the exhaust system will only manifest
after sailing. If water intrusion only occurs after sailing, try
closing the raw water thru-hull fitting while sailing, and see if
the problem goes away. If it does, you'll have to troubleshoot the
exhaust system, or keep your thru-hull closed whenever you're sailing.
In a few cases, leaky head gaskets can result in a small amount
of water getting into the oil. When head gaskets fail, there is
usually evidence of poor running or hard starting caused by loss
of compression and/or water fouling the spark plugs.
Exhaust system problems and head gasket failures have one important
feature in common: It's practically impossible for either exhausted
cooling water or water from head gasket failures to enter the crankcase
without first passing through the combustion chambers. Therefore,
both of these sources of water intrusion would logically result
in poor running, or some other obvious evidence of water being in
the combustion chambers.
In rare cases, both Sherwood and Jabsco water pumps have the potential
of passing a bit of water into the crankcase if their water seal
leaks and the weep holes in their housings become plugged with grease
or other crud. In this scenario, trapped water along the shaft of
the pump can force past the second seal (the one preventing oil
from coming out of the crankcase) and into the oil pan. Oberdorfer
pumps have large weep holes in their housings and don't really have
this same potential.
If there is no indication of water getting in through the combustion
chambers or any other way externally, a crack is usually indicated.
If you do suspect a crack in one of your water jackets, you can
pinch off the water discharge hose coming off the back of the manifold
for several 10 second pressure checks. A flexible impeller pump
in good condition can produce 20 PSI when deadheaded in this fashion.
If there is a crack anywhere in the water-jacketed castings, this
amount of pressure will force water into the oil pan at a rate that
should be unmistakable.
If you can confirm that water is indeed entering your oil pan through
a defective casting, you'll have to remove the engine for disassembly
and repair. Cracks in the floor of the cooling water jacket in the
block are frequently repairable once the engine is disassembled
for $200 to $400, depending on the length of the crack. - Updated:
January 6, 2004
