Mitsubishi MOTORS Space Runner 1998, Workshop Manual

Page: 89 / 1164

ENGINE <4G9> -
On-vehicle Service
11B-15
(4) If the air which has been mixed in with the oil due
to any of the above reasons gets into the high pressure
chamber of the lash adjuster, the air inside the high
pressure chamber will be compressed when the valve
is open and the lash adjuster will over-compress,
resulting in abnormal noise when the valve closes.
This is the same effect as if the valve clearance is
adjusted to be too large by mistake. If the air inside
the lash adjusters is then released, the operation
of the lash adjusters will return to normal.
2. Run the engine at idle for 1 - 3 minutes to let it warm
up.
3. With no load on the engine, repeat the drive pattern shown
in the illustration at left and check if the abnormal noise
disappears. (The noise should normally disappear after
10 - 30 repetitions, but if there is no change in the noise
level after 30 repetitions or more, the problem is probably
not due to air inside the lash adjusters.)
4. After the noise has disappeared, repeat the drive pattern
shown in the illustration at left a further 5 times.
5. Run the engine at idle for 1 - 3 minutes and check that
the noise has disappeared.
High-pressure chamber
Gradually open the
throttle valve.
Drive pattern for air bleeding
Close the throttle
valve.
Approx.
3,000 r/min
15
seconds
15
seconds
Idle speed
Once