2020 JEEP WRANGLER engine

Mileage or time passed (whichever comes first)15,000
30,000
45,000
60,000
75,000
90,000
105,00
120,000
135,000
150,000
Or Months: 12 24 36 48 60 72 84 96 108 120
Or Kilometers:
24,000
48,000
72,000
96,000
120,000
144,000
168,000
192,000
216,000
240,000
Inspect the front suspension, tie rod ends and boot seals,
replace if necessary.XX X
Change brake fluid every 24 months if using DOT 4 brake
fluid. **XXX X X
Inspect the front and rear axle fluid, change if using your
vehicle for police, taxi, fleet, offroad or frequent trailer
towing.XXX X X
Inspect the transfer case fluid. X X X X X
Inspect the CV/Universal joints. X X X X X X X X X X
Drain the fuel filter/water separator unit. X X X X X X X X X X
Replace the fuel filter. X X X X X
Adjust parking brake on vehicles equipped with four-wheel
disc brakes.XXX X X
Replace engine air cleaner filter. X X X X X
Replace air conditioning/cabin air filter X X X X X
Replace accessory drive belt(s). X X
Flush and replace the engine coolant at 10 years or
150,000 miles (240,000 km) whichever comes first.X
Change the automatic transmission fluid and filter.X
177

Mileage or time passed (whichever comes first)15,000
30,000
45,000
60,000
75,000
90,000
105,00
120,000
135,000
150,000
Or Months: 12 24 36 48 60 72 84 96 108 120
Or Kilometers:
24,000
48,000
72,000
96,000
120,000
144,000
168,000
192,000
216,000
240,000
Change automatic transmission fluid and filter if using
your vehicle for any of the following: trailer towing, snow
plowing, heavy loading, taxi, police, delivery service (com-
mercial service), off-road, desert operation or more than
50% of your driving is at sustained high speeds during hot
weather, above 90°F (32°C).XX
Change the manual transmission fluid if using your vehicle
for any of the following: trailer towing, snow plowing,
heavy loading, taxi, police, delivery service (commercial
service), off-road, desert operation or more than 50% of
your driving is at sustained high speeds during hot
weather, above 90°F (32°C).XX
Change transfer case fluid if using your vehicle for any of
the following: police, taxi, fleet, or frequent trailer towing.XX
Replace the engine timing belt, and timing belt tensioner.X
SERVICING AND MAINTENANCE
178

* The actual interval for changing engine oil
and replacing the engine oil filter depends on
the vehicle usage conditions and is signalled
by the warning light or message in the instru-
ment panel. In all cases, never exceed 1 year/
15,000 miles (24,000 km).
** DOT 4 brake fluid is time based only;
mileage intervals do not apply.
WARNING!
• You can be badly injured working on or
around a motor vehicle. Do only service
work for which you have the knowledge
and the right equipment. If you have any
doubt about your ability to perform a
service job, take your vehicle to a com-
petent mechanic.
• Failure to properly inspect and maintain
your vehicle could result in a component
malfunction and effect vehicle handling
and performance. This could cause an
accident.
179

ENGINE COMPARTMENT3.6L Engine
1 — Integrated Power Module (Fuses) 7 — Washer Fluid Reservoir
2 — Battery8 — Engine Coolant Reservoir
3 — Engine Oil Dipstick 9 — Air Cleaner Filter
4 — Automatic Transmission Dipstick (Under Engine Cover) 10 — Coolant Pressure Cap
5 — Engine Oil Fill 11 — Power Steering Fluid Reservoir
6 — Brake Fluid Reservoir
SERVICING AND MAINTENANCE
180

2.8L Diesel Engine
1 — Integrated Power Module (Fuses) 6 — Washer Fluid Reservoir
2 — Battery 7 — Engine Oil Dipstick
3 — Engine Oil Fill 8 — Air Cleaner Filter
4 — Engine Coolant Reservoir 9 — Power Steering Fluid Reservoir
5 — Brake Fluid Reservoir
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Checking Oil Level — Gasoline Engine
To ensure proper lubrication of your vehicle's
engine, the engine oil must be maintained at
the correct level. The engine oil level should
be checked five minutes after a warmed up
engine has been shut off.
Checking the oil while the vehicle is on level
ground will improve the accuracy of the oil
level readings. Always maintain the oil level
within the SAFE zone on the dipstick. Adding
1 quart (0.95 liters) of oil when the reading is
at the bottom of the crosshatch zone will
result in a reading at the top of the cross-
hatch zone on these engines.
CAUTION!
Overfilling or underfilling the crankcase
will cause aeration or loss of oil pressure.
This could damage your engine.
Checking Oil Level — Diesel Engine
To assure proper engine lubrication, the en-
gine oil must be maintained at the correct
level. Check the oil level at regular intervals,
such as every fuel stop.For vehicles equipped with a Diesel Particu-
late Filter (DPF), it is acceptable to have an
oil level up to 3/8 inch (10 mm) above the
MAX line. Beyond 3/8 inch (10 mm) it is
recommended to change the oil.
The best time to check the engine oil level is
about five minutes after a fully warmed en-
gine is shut off.
Checking the oil while the vehicle is on level
ground will improve the accuracy of the oil
level readings. Maintain the oil level between
the MIN and MAX markings on the dipstick.
Adding 1 U.S. Quart (0.95 L) of oil when the
reading is at the MIN mark will result in a
MAX reading on these engines.
Cooling System
WARNING!
• You or others can be badly burned by hot
engine coolant (antifreeze) or steam
from your radiator. If you see or hear
steam coming from under the hood, do
not open the hood until the radiator has
had time to cool. Never open a cooling
WARNING!
system pressure cap when the radiator
or coolant bottle is hot.
• Keep hands, tools, clothing, and jewelry
away from the radiator cooling fan when
the hood is raised. The fan starts auto-
matically and may start at any time,
whether the engine is running or not.
• When working near the radiator cooling
fan, disconnect the fan motor lead or
turn the ignition to the OFF mode. The
fan is temperature controlled and can
start at any time the ignition is in the ON
mode.
Engine Coolant Checks
Check the engine coolant (antifreeze) protec-
tion every 12 months (before the onset of
freezing weather, where applicable). If the
engine coolant (antifreeze) is dirty or rusty in
appearance, the system should be drained,
flushed and refilled with fresh engine coolant
(antifreeze). Check the front of the A/C con-
denser (if equipped) or radiator for any accu-
mulation of bugs, leaves, etc. If dirty, clean
SERVICING AND MAINTENANCE
182

by gently spraying water from a garden hose
vertically down the face of the A/C condenser
(if equipped) or the back of the radiator core.
Check the engine cooling system hoses for
brittle rubber, cracking, tears, cuts, and
tightness of the connection at the coolant
recovery bottle and radiator. Inspect the en-
tire system for leaks. DO NOT REMOVE THE
COOLANT PRESSURE CAP WHEN THE
COOLING SYSTEM IS HOT.
Adding Washer Fluid
The fluid reservoir for the windshield washers
and the rear window washer (if equipped) is
shared. The fluid reservoir is located in the
engine compartment. Be sure to check the
fluid level at regular intervals. Fill the reservoir
with windshield washer solvent only (not radia-
tor antifreeze). When refilling the washer fluid
reservoir, take some washer fluid and apply it to
a cloth or towel and wipe clean the wiper
blades; this will help blade performance.
To prevent freeze-up of your windshield
washer system in cold weather, select a solu-
tion or mixture that meets or exceeds the
temperature range of your climate. This rat-
ing information can be found on most washer
fluid containers.
WARNING!
Commercial windshield washer solvents
are flammable. They could ignite and burn
you. Care must be exercised when filling or
working around the washer solution.
Brake System
In order to assure brake system performance,
all brake system components should be in-
spected periodically. Refer to the “Mainte-
nance Plan” in this section for the proper
maintenance intervals.
WARNING!
Riding the brakes can lead to brake failure
and possibly a collision. Driving with your
foot resting or riding on the brake pedal
WARNING!
can result in abnormally high brake tem-
peratures, excessive lining wear, and pos-
sible brake damage. You would not have
your full braking capacity in an emergency.
Fluid Level Check — Brake Master Cylinder
The fluid level of the master cylinder should
be checked whenever the vehicle is serviced,
or immediately if the brake system warning
light is on. If necessary, add fluid to bring
level within the designated marks on the side
of the reservoir of the brake master cylinder.
Be sure to clean the top of the master cylin-
der area before removing cap. With disc
brakes, fluid level can be expected to fall as
the brake pads wear. Brake fluid level should
be checked when pads are replaced. If the
brake fluid is abnormally low, check the sys-
tem for leaks.
Refer to “Fluids And Lubricants” in “Techni-
cal Specifications” for further information.
183

WARNING!
• Use only manufacturer's recommended
brake fluid. Refer to “Fluids And Lubri-
cants” in “Technical Specifications” for
further information. Using the wrong
type of brake fluid can severely damage
your brake system and/or impair its per-
formance. The proper type of brake fluid
for your vehicle is also identified on the
original factory installed hydraulic mas-
ter cylinder reservoir.
• To avoid contamination from foreign
matter or moisture, use only new brake
fluid or fluid that has been in a tightly
closed container. Keep the master cylin-
der reservoir cap secured at all times.
Brake fluid in a open container absorbs
moisture from the air resulting in a lower
boiling point. This may cause it to boil
unexpectedly during hard or prolonged
braking, resulting in sudden brake fail-
ure. This could result in a collision.
• Overfilling the brake fluid reservoir can
result in spilling brake fluid on hot en-
gine parts, causing the brake fluid to
WARNING!
catch fire. Brake fluid can also damage
painted and vinyl surfaces, care should
be taken to avoid its contact with these
surfaces.
• Do not allow petroleum based fluid to
contaminate the brake fluid. Brake seal
components could be damaged, causing
partial or complete brake failure. This
could result in a collision.
Manual Transmission
Fluid Level Check
Check the fluid level by removing the fill
plug. The fluid level should be between the
bottom of the fill hole and a point not more
than 3/16 of an inch (4.76 mm) below the
bottom of the hole.
Add fluid, if necessary, to maintain the
proper level.
Automatic Transmission
Fluid Level Check — Gasoline Engine
It is best to check the fluid level when the
transmission is at normal operating tempera-
ture (approximately 180°F/82°C). This oc-
curs after at least 15 miles (25 km) of driv-
ing. At normal operating temperature, the
fluid cannot be held comfortably between the
fingertips.
Use the following procedure to check the
transmission fluid level properly:
1. Park the vehicle on level ground.
2. Remove the engine cover by pulling it up
off the mounting studs (two in the front
and two in the rear).
3. Run the engine at normal idle speed for at
least 60 seconds, and leave the engine
running for the rest of this procedure.
4. Fully apply the parking brake, and press
the brake pedal.
SERVICING AND MAINTENANCE
184