Lash Adjuster Check - Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement

11A-14
ENGINE <4G9> –

LASH ADJUSTER CHECK

If an abnormal noise (knocking) that seems to be coming
from the lash adjuster is heard after starting the engine and
does not stop, carry out the following check.
NOTE
(1) The abnormal noise which is caused by a problem
(2) If there is a problem with the lash adjusters, the noise
1. Start the engine.
2. Check that the noise occurs immediately after the engine
is started, and that the noise changes in accordance with
changes in the engine speed.
If the noise does not occur immediately after the engine
is started, or if it does not change in accordance with
the engine speed, the problem is not being caused by
the lash adjusters, so check for some other cause of the
problem. Moreover, if the noise does not change in
accordance with the engine speed, the cause of the
problem is probably not with the engine. (In these cases,
the lash adjusters are normal.)
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
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 has disappeared, the
cause of the noise was probably that oil sludge had caused
the lash adjusters to become stuck. If this happens, clean
the lash adjusters (Refer to the Engine Workshop Manual).
If the noise level does not change, go to step 5.
5. Bleed the air from the lash adjusters. (Refer to P.11A-15.)
6. If the noise does not disappear even after the air has
been bled from the lash adjusters, clean the lash adjusters.
(Refer to the Engine Workshop Manual.)
<LASH ADJUSTER AIR BLEEDING>
On-vehicle Service
with the lash adjusters is generated after the engine
is started, and will vary according to the engine speed.
However, this noise is not related to the actual engine
load.
Because of this, if the noise does not occur immediately
after the engine is started, if it does not change in
accordance with the engine speed, or if it changes
in accordance with the engine load, the source of
the noise is not the lash adjusters.
will almost never disappear, even if the engine has
been run at idle to let it warm up.
The only case where the noise might disappear is
if the oil in the engine has not been looked after properly
and oil sludge has caused the lash adjusters to stick.
D).