SERVICE MANUAL NUMBER 26
TROUBLESHOOTING
Water in Engine
Important Information
IMPORTANT: First determine location of water in engine. This information can be of
great help when trying to determine where the water came from and how it got into
the engine. The three most common problems are “water on top of pistons, water in
crankcase oil or water in crankcase oil and on top of pistons.”
The first step, after locating water, is to remove all the water from the engine by removing
all spark plugs and pumping cylinders out by cranking engine over. Next change oil and filter.
Now, start engine and see if problem can be duplicated. If problem can be duplicated, there
is probably a mechanical problem. If the problem cannot be duplicated, the problem is either
an operator error or a problem that exists only under certain environmental conditions.
If water is contained to cylinder(s) only, it is usually entering through the intake system,
exhaust system or head gasket.
If the water is contained to crankcase only, it is usually caused by a cracked or porous block,
a flooded bilge or condensation.
If the water is located in both the cylinder(s) and the crankcase, it is usually caused by water
in the cylinders getting past the rings and valves or complete submersion.
Check for rust in the intake manifold or exhaust manifolds. Rust in these areas will show that
if the water entered these areas.
If water is contained to cylinder(s) only, it is usually entering through the intake system,
exhaust system or head gasket.
Water In Crankcase
Cause
Special Information
Boat has been submerged or bilge water
was high enough to run in through dipstick
tube
Water in boat bilge
Refer to “Water in Engine” (“On Top of
Pistons”)
Water seeping past piston rings or valves
Engine running cold
Defective thermostat, missing thermostat;
prolonged idling in cold water
Intake manifold leaking near a water
passage
Check cylinder head, cylinder block, and
intake manifold
Cracked or porous casting
Index
90-861329--1
MARCH 1999
Page 1C-29
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 181 CID |
| Model Year | 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(6 votes, average: 5 out of 5)
Marine readers have rated Mercury MerCruiser GM 4 Cylinder 181 cid 3.0L Marine Engines Service Manual Number 26 5.0 out of 5.0 based on 6 product reviews. Thanks for sharing this material. Helps a lot after suffering with bad mechanics. spend too much money and nothing very good
great manual, makes impossible jobs possible. without a manual you can not do the job, a must have.
Great resource. Excellent information provided.
Need help to install automate choke
Need help to instal automate choke