Mitsubishi Pajero Pinin. Manual - part 13

ENGINE <4G9-GDI> –

On-vehicle Service

11A-12

Measure the compression pressure for all the cylinders,
and check that the pressure differences of the cylinders are
below the limit.

Limit: Max. 100 kPa

If there is a cylinder with compression or a compression
difference that is outside the limit, pour a small amount
of engine oil through the spark plug hole, and repeat the
operations in steps 6 and 7.

(1) If the compression increases after oil is added, the

cause of the malfunction is a worn or damaged piston
ring and/or cylinder inner surface.

(2) If the compression does not rise after oil is added,

the cause is a burnt or defective valve seat, or pressure
is leaking from the gasket.

Connect the crank angle sensor connector.

10. Install the spark plugs and ignition coils.
11. Use the MUT-

to erase the diagnosis codes.

NOTE
This will erase the diagnosis code resulting from the crank
angle sensor connector being disconnected.

MANIFOLD VACUUM CHECK

Before inspection, set the vehicle to the pre-inspection
condition.

Turn off the ignition switch.

Connect the engine tachometer or connect the MUT-

to the diagnosis connector.

Disconnect the ventilation hose from the positive crankcase
ventilation (PCV) valve, and then connect a vacuum gauge
to the ventilation hose. Plug the positive crankcase
ventilation (PCV) valve.

Start the engine and run it at idle for 4 minutes or more,
and then check the intake manifold vacuum while the
engine is idling.

Limit: Min. 60 kPa

Turn off the ignition switch.

Remove the vacuum gauge, and then connect the
ventilation hose to the positive crankcase ventilation (PCV)
valve.

Remove the engine tachometer or the MUT-

II.

Vacuum gauge

Plug

Positive crankcase
ventilation (PCV) valve

ENGINE <4G9-GDI> –

On-vehicle Service

11A-13

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

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.

(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.

Start the engine.

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.)

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.)

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.

Bleed air from the lash adjusters. (Refer to P.11A-14, LASH
ADJUSTER AIR BLEEDING.)

If the noise has not disappeared even after the air bleeding,
clean the lash adjusters. (Refer to the Engine Workshop
Manual.)

ENGINE <4G9-GDI> –

On-vehicle Service

11A-14

<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.

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.

(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.

Good

High-pressure chamber

ENGINE <4G9-GDI> –

On-vehicle Service

11A-15

Run the engine at idle for 1 – 3 minutes to let it warm up.

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.)

After the noise has disappeared, repeat the drive pattern
shown in the illustration at left a further 5 times.

Run the engine at idle for 1 – 3 minutes and check that
the noise has disappeared.

Gradually open the
throttle valve.

Drive pattern for air bleeding

Close the throttle
valve.

Approx.
3,000 r/min

15
seconds

Idle speed

Once

Content .. 11 12 13 14 ..