Section 01 ENGINES (1503 4-TEC)
Subsection 01 (LEAK TEST)
1
R1503motr156A
1. Intake rocker arms
Protect the hull area then position the wrench
lever so that it rest against hull to prevent further
crankshaft rotation.
Install gauge adapter into previously cleaned spark
plug hole.
Connect to adequate air supply.
NOTE: Each tester will have specific instruction
on the gauge operation and required pressure.
Set needle of measuring gauge to zero.
Supply combustion chamber with air.
1
R1503motr157A
2
3
1. Measuring gauge
2. Adequate adapter for spark plug hole
3. Air supply
Note the amount of leaking or percentage (de-
pending on tester).
LEAKAGE
PERCENTAGE
ENGINE
CONDITION
0% to 15% Excellent condition.
16% to 25%
Good condition
26% to 40%
Fair condition; engine will run
and performance might be
down in some cases.
41% and higher
Poor condition, diagnose and
repair engine.
Proceed the same way with remaining cylinders.
DIAGNOSIS
Pressurize area to be tested, spray soap/water so-
lution at the indicated location and look and/or lis-
ten for air bubbles.
– air escaping on intake port means leaking intake
valve(s)
– air escaping on exhaust port means leaking ex-
haust valve(s)
– air bubbles out of coolant tank means leaking
cylinder head gasket
– air escaping into crankcase area means exces-
sively worn and/or broken piston rings.
POSSIBLE ENGINE LEAKAGE
AREA
Spray soap/water solution at the indicated location
and look and/or listen for air bubbles.
Paying attention to the following checkpoints:
– clamp(s) tightened
– coolant hoses
– air/oil escaping from crankcase means dam-
aged gasket(s) and/or loosened screws (refer
to ENGINE BLOCK)
– air/water escaping from cylinder/head means
damaged gasket(s) and/or loosened screws (re-
fer to CYLINDER HEAD)
– oilycontaminationonweephole(speedsen-
sor area) means a damaged oil seal on coolant
pump shaft
SMR2005-032 3
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