Idle Operating Temperature Troubleshooting (Below Range) - Evinrude E-TEC E115DPLSCR Service Manual

COOLING SYSTEM
ENGINE TEMPERATURE CHECK
Typical pyrometer readings at IDLE speed should
be 150°F ± 20°F (66°C ± 11°C).
If you get low or inaccurate read-
IMPORTANT:
ings with a digital pyrometer, coat the probe loca-
tion with Thermal Joint Compound, P/N 322170.
Idle Operating Temperature
Troubleshooting (Below Range)
If engine IDLE temperature is below operating
range 160°F ± 20°F (71°C ± 11°C), check thermo-
stat and pressure relief valve operation.
Pressure Relief Valve Inspection
The pressure relief valve should be closed at
IDLE speed. Water should not flow past the
plunger and seal.
Start the outboard and check IDLE operating tem-
perature.
If IDLE temperature is too low, check pressure
relief valve plunger and seal for damage or debris
that could prevent the valve from closing com-
pletely.
If IDLE temperature is still below operating range,
replace pressure relief valve assembly and
plunger seal.
222
To test pressure relief valve operation, monitor
temperature at the thermostat housing with Tem-
perature Gun, P/N 772018, or digital pyrometer.
Confirm normal IDLE operating temperature.
Slowly increase engine speed from IDLE, up
through 3000 RPM.
Engine temperature should decrease from normal
IDLE temperatures as pressure relief valve opens.
Valve should open at approximately 2500 RPM.
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If temperature decreases at a lower RPM, replace
pressure relief valve assembly.
Refer to PRESSURE RELIEF VALVE SERVIC-
ING on p. 224.
Thermostat Inspection
If IDLE temperature is still below operating range,
inspect thermostats and thermostat seals.
Check position of thermostat seal and how ther-
mostat seals against cylinder head. Seal must be
properly fitted to flange of thermostat.
1
1. Thermostat seal
Check thermostat for cracks, heat damage, or
signs of corrosion. Check for proper operation.
Thermostat opens at 143°F (62°C).
Refer to THERMOSTAT SERVICING on p. 223.
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