Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 22

ENGINE <4G6-MPI> -
Good
On-vehicle Service
3. While the engine is idling, check that the noise level does
not change when the engine load is varied (for example,
by shifting from N ® D).
If the noise level changes, the cause of the noise is
probably parts striking because of worn crankshaft
bearings or connecting rod bearings. (In such cases, the
lash adjusters are normal.)
4. After the engine has warmed up, run it at idle and check
if any noise can be heard.
If the noise has become smaller or disappeared, oil sludge
could make the lash adjusters stick. Clean the lash
adjusters. (Refer to the Engine Workshop Manual.) If not
improved, go to step 5.
5. Bleed air from the lash adjusters.
6. If the noise has not disappeared even after the air
bleeding, clean the lash adjusters. (Refer to the Engine
Workshop Manual.)
<LASH ADJUSTER AIR BLEEDING>
NOTE
(1) If the vehicle is parked on a slope for a long period
of time, the amount of oil inside the lash adjuster
will decrease, and air may get into the high pressure
chamber when starting the engine.
(2) After parking the vehicle for long periods, the oil drains
out of the oil passage, and it takes time for the oil
to be supplied to the lash adjuster, so air can get
into the high pressure chamber.
(3) If either of the above situations occur, the abnormal
noise can be eliminated by bleeding the air from inside
the lash adjusters.
1. Check the engine oil and replenish or replace the oil
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.
11C-13