Mitsubishi Galant. Manual - part 23
ON VEHICLE SERVICE
TSB Revision
ENGINE MECHANICAL <2.4L>
11A-11
If the noise is reduced or disappears, clean the lash adjuster
(Refer to GROUP 11B-Engine overhaul
−
Rocker Arms and
Camshaft
−
Inspection
.) As it is suspected that the
noise is due to seizure of the lash adjuster. If there is no
change in the level of the abnormal noise, proceed to step 5.
5. Run the engine to bleed the lash adjuster system. (Refer to
.)
6. If the abnormal noise does not disappear after air bleeding
operation, clean the lash adjuster (Refer to GROUP 11B-
Engine overhaul
−
Rocker Arms and Camshaft
−
Inspection
.)
Bleeding lash adjuster system
NOTE: Parking the vehicle on a grade for a long time may
decrease oil in the lash adjuster, causing air to enter the high
pressure chamber when starting the engine.
NOTE: After parking for many hours, oil may run out from the
oil passage and take time before oil is supplied to the lash
adjuster, causing air to enter the high pressure chamber.
NOTE: In the above cases, abnormal noise can be eliminated
by bleeding the lash adjuster system.
1. Check engine oil and add or change oil if required.
NOTE: If the engine oil level is low, air is sucked from the oil
screen, causing air to enter the oil passage.
NOTE: If the engine oil level is higher than specification, oil
may be stirred by the crankshaft, causing oil to be mixed
with a large quantity of air.
NOTE: If oil is deteriorated, air is not easily separated from
oil, increasing the quantity of air contained in oil.
NOTE: If air mixed with oil enters the high pressure chamber
inside the lash adjuster from the above causes, air in the
high pressure chamber is compressed excessively while the
valve is opened, resulting in an abnormal noise when the
valve closes.
This is the same phenomenon as that observed when the
valve clearance has become excessive. The lash adjuster
can resume normal function when air entered the lash
adjuster is removed.
2. Idle the engine for one to three minutes to warm it up.
3. Repeat the operation pattern, shown in left figure, at no load
to check for abnormal noise. (Usually the abnormal noise is
eliminated after repetition of the operation 10 to 30 times. If,
however, no change is observed in the level of abnormal
noise after repeating the operation more than 30 times,
suspect that the abnormal noise is due to some other
factors.)
4. After elimination of abnormal noise, repeat the operation
shown in left figure five more times.
AKX00328
GOOD
MINIMUM
MAXIMUM
AB
AKX00329
HIGH-
PRESSURE
CHAMBER
AB
AKX00330
OPEN THROTTLE
VALVE GRADUALLY
CLOSE
THROTTLE VALVE
APPROXI-
MATELY
3,000 r/min
IDLING
OPERATION
ONCE
15s
15s
AIR BLEEDING OPERATION PATTERN
AB