Mitsubishi 4G6 Manual page 49

Good
Drive pattern for air bleeding
Gradually open the
throttle valve.
Approx.
3,000 r/min.
Idle speed
15 15
seconds seconds
Once
ENGINE <6A1> - ENGINE <6A1> -
1. Check the engine oil and replenish or replace the oil
High
pressure
chamber
2. Run the engine at idle for 1 - 3 minutes to let it warm
Close the throttle
3. With no load on the engine, repeat the drive pattern shown
valve.
4. After the noise has disappeared, repeat the drive pattern
5. Run the engine at idle for 1 - 3 minutes and check that
On-vehicle Service On-vehicle Service
if necessary.
NOTE
(1) If there is a only small amount of oil, air will be drawn
in through the oil screen and will get into the oil
passage.
(2) If the amount of oil is greater than normal, then the
oil will being mixed by the crankshaft and a large
amount of air may get mixed into the oil.
(3) If the oil is degenerated, air and oil will not separate
easily in oil, and the amount of air mixed into the
oil will increase.
(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.
up.
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.)
shown in the illustration at left a further 5 times.
the noise has disappeared.
11B-13