Dodge Neon / Neon SRT-4. Manual - part 65
WARNING:
WITH
TOOL
IN
PLACE
PRESSURE
BUILDS UP FAST. ANY EXCESSIVE AMOUNT OF
PRESSURE BUILT UP BY CONTINUOUS ENGINE
OPERATION MUST BE RELEASED TO A SAFE
PRESSURE POINT. NEVER PERMIT PRESSURE TO
EXCEED 138 kPa (20 psi).
If the needle on the dial does not fluctuate, race
the engine a few times. If an abnormal amount of
coolant or steam is emitted from the tailpipe, it may
indicate a faulty head gasket, cracked engine block or
cylinder head.
There may be internal leaks which can be deter-
mined by removing the oil dipstick. If water globules
appear intermixed with the oil, it will indicate a
internal leak in the engine. If there is an internal
leak, the engine must be disassembled for repair.
DIAGNOSIS AND TESTING - COOLING SYSTEM
AERATION
Low coolant level in a cross flow radiator will
equalize in both tanks with engine off. With engine
at running and at operating temperature, the high
pressure inlet tank runs full and the low pressure
outlet tank drops. If this level drops below the top of
the transmission oil cooler, aeration will occur draw-
ing air into the water pump resulting in the follow-
ing:
• High reading shown on the temperature gauge.
• Loss of coolant flow through the heater core.
• Corrosion in the cooling system.
• Transmission oil will become hotter.
• Water pump seal may run dry, increasing the
risk of premature seal failure.
• Combustion gas leaks into the coolant can also
cause the above problems.
DIAGNOSIS AND TESTING - COOLING SYSTEM
DEAERATION
Air can only be removed from the system by gath-
ering under the pressure cap. On the next heat up it
will be pushed past the pressure cap into the coolant
recovery bottle by thermal expansion of the coolant.
It then escapes to the atmosphere in the coolant
recovery bottle and is replaced with coolant on cool
down.
To effectively deaerate the system, multiple ther-
mal cycles of the system may be required.
NOTE: Deaeration does not occur at engine idle—
higher engine speeds are required. Normal driving
will deaerate cooling system.
STANDARD PROCEDURE
STANDARD PROCEDURE - COOLANT LEVEL
SERVICING
NOTE: The cooling system is closed and designed
to maintain coolant level to the top of the radiator.
When servicing requires a coolant level check in
the engine, the engine must be off and not under
pressure. Drain several ounces of coolant from the
radiator draincock while observing the coolant recov-
ery container. Coolant level in the container should
drop slightly. Then remove the pressure cap, (Fig. 3).
Coolant should be to the top of the pressure cap
neck. If not, and the coolant level in the recovery
container is at the ADD mark there is a air leak in
the recovery system. Check hose or hose connections
to the recovery container, radiator filler neck or the
pressure cap seal to the radiator filler neck for leaks.
STANDARD PROCEDURE - ROUTINE COOLANT
LEVEL CHECK
NOTE: Do not remove pressure cap for routine
coolant level inspections.
The coolant recovery/reserve system provides a
quick visual method for determining the coolant level
without removing the radiator cap. Simply observe,
with the engine idling and warmed up to normal
operating temperature, that the level of the coolant
in the recovery/reserve container (Fig. 4) is between
the FULL HOT and ADD marks.
STANDARD PROCEDURE - ADDING
ADDITIONAL COOLANT
NOTE: The radiator cap should not be removed.
When additional coolant is needed, it should be
added to the coolant recovery/reserve container (Fig.
3). Use only a 50/50 concentration of the recom-
mended ethylene glycol type antifreeze and distilled
water. (Refer to LUBRICATION & MAINTENANCE/
FLUID TYPES - DESCRIPTION)
7 - 18
ENGINE - 2.0L SOHC
PL/SRT-4
ENGINE - 2.0L SOHC (Continued)