Mitsubishi Electric Lancer Evolution-VII Workshop Manual page 1314

ENGINE -
On-vehicle Service
(2) If there is a problem with the lash adjusters, the noise
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.
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.
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 GROUP 11B - Rocker Arms and Camshaft.)
<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.
11A-13