Water In Engine
If water is contained to cylinder(s) only, it is usually
entering through the intake system, exhaust system,
or head gasket.
Important Information
If the water is contained to crankcase only, it is usual-
ly caused by a cracked or porous block, a flooded
bilge, or condensation.
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 pis-
tons, water in crankcase oil, water in crankcase
oil and on top of pistons.”
If the water is located in both the cylinder(s) and the
crankcase, it is usually caused by water in the cylin-
ders getting past the rings and valves, or complete
submersion.
Checking for rust in the intake manifold or exhaust
manifolds is a good idea. Rust in these areas will give
clues if the water entered these areas.
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 dupli-
cated, there more than likely is a mechanical prob-
lem. If the problem cannot be duplicated, the problem
is either an operator error or a problem that exists
only under certain environmental conditions.
Water on Top of Pistons
Cause
Special Information
Operator shut engine off at high RPM
Engine out of tune, poor fuel, high idle RPM,
timing set too high
Engine “diesels” or tries to run backwards
Rain water running into flame arrestor
Spark plug misfiring
Hatch cover
Improper combustion causes moisture in the air
to accumulate in the cylinder
Backwash through the exhaust system
Improper engine or exhaust hose installation
Cracked exhaust manifold
Improper manifold to elbow gasket installation
Loose cylinder head bolts
Blown cylinder head gasket
Check for warped cylinder head or cylinder block
Cracked valve seat
Check cylinder heads, cylinder block, and intake
manifold
Porous or cracked casting
Index
90-823224--2 796
TROUBLESHOOTING - 1C-25
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 454 CID, Mercury MerCruiser 502 CID |
| Model Year | 1993, 1994, 1995, 1996, 1997 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(4 votes, average: 4.5 out of 5)
Marine readers have rated 1993 1997 Mercury-MerCruiser GM V8 454 CID 7.4L and 502 CID 8.2L Marine Engines Service Manual Number 16 4.5 out of 5.0 based on 4 product reviews. Hugely helpful service manual! Perfect. Thank you!
Manuals are all Important for Technician
This book is invaluable if you do your own repairs. Great book.
Could not find a copy until a search brought me here.
Excellent print.
Thank you