Jeep Wrangler Sport 2010 User manual

2010 ENGINE
3.8L - Service Information - Wrangler
DESCRI TION
DESCRIPTION
Fig. 1: ENGINE IDENTIFICATION
Courtesy of CHRYSLER LLC
The 3.8 Liter (231 cu. in.) engine is 60° V6 engines with cast iron cylinder bloc s and aluminum cylinder
heads. The engine uses a single, bloc mounted camshaft, roller lifters with pushrods to actuate the valves and
either crac ed cap, or standard cap, forged connecting rods. The engine does not have provisions for a free
wheeling valve train.
The firing order is 1-2-3-4-5-6. The left cylinder ban is numbered 2, 4, and 6. The right cylinder ban is
numbered 1, 3, and 5.
The engine identification number is located on the rear of the cylinder bloc just below the cylinder head.
DIAGNOSIS AND TESTING
INTRODUCTION
Engine diagnosis is helpful in determining the causes of malfunctions not detected and remedied by routine
maintenance.
These malfunctions may be classified as either mechanical (e.g., a strange noise), or performance (e.g., engine
idles rough and stalls).
2010 Jeep Wrangler Sport
2010 ENGINE 3.8L - Service Information - Wrangler
2010 Jeep Wrangler Sport
2010 ENGINE 3.8L - Service Information - Wrangler
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Refer to the Engine Mechanical and the Engine Performance diagnostic charts, for possible causes and
corrections of malfunctions. See PERFOR ANCE. See ECHANICAL.
For fuel system diagnosis, refer to Non-DTC Diagnostics/Driveability - Gas - Diagnosis and Testing .
Additional tests and diagnostic procedures may be necessary for specific engine malfunctions that cannot be
isolated with the Service Diagnosis charts. Information concerning additional tests and diagnosis is provided
within the following:
Cylinder Compression Pressure Test: Refer to CYLINDER CO PRESSION PRESSURE TEST.
Cylinder Combustion Pressure Lea age Test: Refer to CYLINDER CO BUSTION PRESSURE
LEAKAGE TEST.
Engine Cylinder Head Gas et Failure Diagnosis: Refer to CYLINDER HEAD GASKET.
Inta e Manifold Lea age Diagnosis: Refer to INTAKE ANIFOLD LEAKS.
Hydraulic Lash Adjuster Noise Diagnosis: Refer to HYDRAULIC LIFTERS.
Engine Oil Lea Inspection: Refer to ENGINE OIL LEAK INSPECTION.
PERFOR ANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Wea battery. 1. Test battery. Charge or replace
as necessary
Refer to Electrical/Battery
System - Diagnosis and Testing .
2. Corroded or loose battery
connections.
2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to terminals.
3. Faulty starter. 3. Test starting system. Refer to
Electrical/Starting - Diagnosis
and Testing .
4. Faulty coil(s) or control unit. 4. Test and replace as needed.
(Refer to Appropriate Diagnostic
Information)
5. Incorrect spar plug gap. 5. Set gap. Refer to
Electrical/Ignition Control -
Specifications .
6. Contamination in fuel system. 6. Clean system and replace fuel
filter.
7. Faulty fuel pump. 7. Test fuel pump and replace as
needed. (Refer to Appropriate
Diagnostic Information)
8. Incorrect engine timing. 8. Chec for a s ipped timing
belt/chain.
ENGINE STALLS OR IDLES
ROUGH
1. Idle speed too low. 1. Test minimum air flow. (Refer
to Appropriate Diagnostic
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Information)
2. Incorrect fuel mixture. 2. (Refer to Appropriate
Diagnostic Information)
3. Inta e manifold lea age. 3. Inspect inta e manifold,
manifold gas et, and vacuum
hoses.
4. Faulty ignition coil(s). 4. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
ENGINE LOSS OF POWER 1. Dirty or incorrectly gapped
plugs.
1. Clean plugs and set gap.
2. Contamination in fuel system. 2. Clean system and replace fuel
filter.
3. Faulty fuel pump. 3. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
4. Incorrect valve timing. 4. Correct valve timing.
5. Lea ing cylinder head gas et. 5. Replace cylinder head gas et.
6. Low compression. 6. Test compression of each
cylinder.
7. Burned, warped, or pitted
valves.
7. Replace valves.
8. Plugged or restricted exhaust
system.
8. Perform exhaust restriction test.
Refer to Exhaust System -
Diagnosis and Testing . Install
new parts, as necessary.
9. Faulty ignition coil(s). 9. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
ENGINE MISSES ON
ACCELERATION
1. Dirty or incorrectly gapped
spar plugs.
1. Clean spar plugs and set gap.
2. Contamination in Fuel System. 2. Clean fuel system and replace
fuel filter.
3. Burned, warped, or pitted
valves.
3. Replace valves.
4. Faulty ignition coil(s). 4. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
ENGINE MISSES AT HIGH
SPEED
1. Dirty or incorrect spar plug
gap.
1. Clean spar plugs and set gap.
2. Faulty ignition coil(s). 2. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
3. Dirty fuel injector(s). 3. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
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ECHANICAL
4. Contamination in fuel system. 4. Clean system and replace fuel
filter.
CONDITION POSSIBLE CAUSES CORRECTION
NOISY VALVES 1. High or low oil level in
cran case.
1. Chec and correct engine oil
level.
2. Thin or diluted oil. 2. Change oil to correct viscosity.
3. Thic oil 3. (a) Change engine oil and filter.
(b) Run engine to operating
temperature.
(c) Change engine oil and filter
again.
4. Low oil pressure. 4. Chec and correct engine oil
pressure problem.
5. Dirt in hydraulic lifters/lash
adjusters.
5. Replace hydraulic lifters/lash
adjusters.
6. Worn roc er arms. 6. Inspect oil supply to roc er
arms.
7. Worn hydraulic lifters/lash
adjusters.
7. Replace hydraulic lifters/lash
adjusters.
8. Worn valve guides. 8. Replace cylinder head
assembly.
9. Excessive runout of valve seats
on valve faces.
9. Grind valve seats and valves.
CONNECTING ROD NOISE 1. Insufficient oil supply. 1. Chec engine oil level.
2. Low oil pressure. 2. Chec engine oil level. Inspect
oil pump relief valve and spring.
3. Thin or diluted oil. 3. Change oil to correct viscosity.
4. Thic oil 4. (a) Change engine oil and filter.
(b) Run engine to operating
temperature.
(c) Change engine oil and filter
again.
5. Excessive bearing clearance. 5. Measure bearings for correct
clearance. Repair as necessary.
6. Connecting rod journal out-of-
round.
6. Replace cran shaft or grind
surface.
7. Misaligned connecting rods. 7. Replace bent connecting rods.
MAIN BEARING NOISE 1. Insufficient oil supply. 1. Chec engine oil level.
2. Low oil pressure. 2. Chec engine oil level. Inspect
oil pump relief valve and spring.
3. Thin or diluted oil. 3. Change oil to correct viscosity.
4. Thic oil 4. (a) Change engine oil and filter.
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(b) Run engine to operating
temperature.
(c) Change engine oil and filter
again.
5. Excessive bearing clearance. 5. Measure bearings for correct
clearance. Repair as necessary.
6. Excessive end play. 6. Chec thrust bearing for wear
on flanges.
7. Cran shaft journal out-of-round
or worn.
7. Replace cran shaft or grind
journals.
8. Loose flywheel or torque
converter.
8. Tighten to correct torque.
OIL PRESSURE DROP 1. Low oil level. 1. Chec engine oil level.
2. Faulty oil pressure
sensor/switch.
2. Replace oil pressure
sensor/switch.
3. Low oil pressure. 3. Chec oil pressure
sensor/switch and main bearing oil
clearance.
4. Clogged oil filter. 4. Install new oil filter.
5. Worn parts in oil pump. 5. Replace worn parts or pump.
6. Thin or diluted oil. 6. Change oil to correct viscosity.
7. Oil pump relief valve stuc . 7. Remove valve and inspect,
clean, or replace.
8. Oil pump suction tube loose. 8. Remove oil pan and install new
tube or clean, if necessary.
9. Oil pump cover warped or
crac ed.
9. Install new oil pump.
10. Excessive bearing clearance. 10. Measure bearings for correct
clearance.
OIL LEAKS 1. Misaligned or deteriorated
gas ets.
1. Replace gas et(s).
2. Loose fastener, bro en or
porous metal part.
2. Tighten, repair or replace the
part.
3. Misaligned or deteriorated cup
or threaded plug.
3. Replace as necessary.
OIL CONSUMPTION OR
SPARK PLUGS FOULED
1. PCV system malfunction. 1. Chec system and repair as
necessary. (Refer to
EVAPORATIVE E ISSIONS .
2. Worn, scuffed or bro en rings. 2. Hone cylinder bores. Install
new rings.
3. Carbon in oil ring slots. 3. Install new rings.
4. Rings fitted too tightly in
grooves.
4. Remove rings and chec
grooves. If groove is not proper
width, replace piston.
5. Worn valve guide(s). 5. Replace cylinder head
2010 Jeep Wrangler Sport
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ENGINE OIL LEAK INSPECTION
Begin with a thorough visual inspection of the engine, particularly at the area of the suspected lea . If an oil
lea source is not readily identifiable, the following steps should be followed:
1. Do not clean or degrease the engine at this time because some solvents may cause rubber to swell,
temporarily stopping the lea .
2. Add an oil soluble dye (use as recommended by manufacturer). Start the engine and let idle for
approximately 15 minutes. Chec the oil level indicator to ma e sure the dye is thoroughly mixed as
indicated with a bright yellow color under a blac light.
3. Using a blac light, inspect the entire engine for fluorescent dye, particularly at the suspected area of oil
lea . If the oil lea is found and identified, repair as necessary.
4. If dye is not observed, drive the vehicle at various speeds for approximately 24 m (15 miles), and repeat
inspection.
5. If the oil leak source is not positively identified at this time , proceed with the AIR LEAK
DETECTION TEST METHOD as follows:
Disconnect the fresh air hose (ma e-up air) at the cylinder head cover and plug or cap the outlet on
the cover.
Remove the PCV valve hose from the cylinder head cover. Cap or plug the PCV valve outlet on the
cover.
Attach an air hose with pressure gauge and regulator to the oil level indicator tube.
Gradually apply air pressure from 1 psi to 2.5 psi maximum while applying soapy water at the
suspected source. Adjust the regulator to the suitable test pressure that provides the best bubbles
which will pinpoint the lea source. If the oil lea is detected and identified, repair per service
information procedures.
If the lea age occurs at the cran shaft rear oil seal area, refer to INSPECTION FOR REAR
SEAL AREA LEAKS.
6. If no lea s are detected, turn off the air supply. Remove the air hose, all plugs, and caps. Install the PCV
valve and fresh air hose (ma e-up air). Proceed to next step.
7. Clean the oil off the suspect oil lea area using a suitable solvent. Drive the vehicle at various speeds
approximately 24 m (15 miles). Inspect the engine for signs of an oil lea by using a blac light.
assembly.
6. Valve stem seal(s) worn or
damaged.
6. Replace seal(s).
CAUTION: Do not subject the engine assembly to more than 20.6 k a (3
SI) of test pressure.
NOTE: If oil leakage is observed at the oil level indicator tube to block location;
remove the tube, clean and reseal using Mopar® Stud AND Bearing Mount
(press fit tube applications only), and for O-ring style tubes, remove tube
and replace the O-ring seal.
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INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the source of an oil lea in the rear seal area of the engine, a more
involved inspection is necessary. The following steps should be followed to help pinpoint the source of the lea .
If the lea age occurs at the cran shaft rear oil seal area:
1. Disconnect the battery.
2. Raise the vehicle.
3. Remove torque converter or clutch housing cover and inspect rear of bloc for evidence of oil. Use a
blac light to chec for the oil lea . If a lea is present in this area, remove transmission for further
inspection.
a. Circular spray pattern generally indicates seal lea age or cran shaft damage.
b. Where lea age tends to run straight down, possible causes are a porous bloc , oil gallery cup plug,
bedplate to cylinder bloc mating surfaces and seal bore. See proper repair procedures for these
items.
4. If no lea s are detected, pressurize the cran case as previously described in step 5 in ENGINE OIL
LEAK INSPECTION.
5. If the lea is not detected, very slowly turn the cran shaft and watch for lea age. If a lea is detected
between the cran shaft and seal while slowly turning the cran shaft, it is possible the cran shaft seal
surface is damaged. The seal area on the cran shaft could have minor nic s or scratches that can be
polished out with emery cloth.
6. For bubbles that remain steady with shaft rotation, no further inspection can be done until disassembled.
7. After the oil lea root cause and appropriate corrective action have been identified, replace component(s)
as necessary.
CYLINDER CO PRESSION PRESSURE TEST
CAUTION: Do not exceed 20.6 k a (3 psi).
CAUTION: Use extreme caution when crankshaft polishing is necessary to
remove minor nicks and scratches. The crankshaft seal flange is
especially machined to complement the function of the rear oil seal.
CAUTION: Do not exceed 20.6 k a (3 psi).
CAUTION: Use extreme caution when crankshaft polishing is necessary to
remove minor nicks and scratches. The crankshaft seal flange is
especially machined to complement the function of the rear oil seal.
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The results of a cylinder compression pressure test can be utilized to diagnose several engine malfunctions.
Ensure the battery is completely charged and the engine starter motor is in good operating condition. Otherwise
the indicated compression pressures may not be valid for diagnosis purposes.
1. Chec engine oil level and add oil if necessary.
2. Drive the vehicle until engine reaches normal operating temperature. Select a route free from traffic and
other forms of congestion, observe all traffic laws, and accelerate through the gears several times bris ly.
3. Remove all spar plugs from engine. As spar plugs are being removed, chec electrodes for abnormal
firing indicators such as fouled, hot, oily, etc. Record cylinder number of spar plug for future reference.
4. Remove the Auto Shutdown (ASD) relay from the Power Distribution Center (PDC).
5. Insert compression gauge adaptor Special Tool 8116 or the equivalent, into the #1 spar plug hole in
cylinder head. Connect the 0-500 psi (Blue) pressure transducer (Special Tool CH7059) with cable
adaptors to the DRBIII®. For Special Tool identification, see Engine - Special Tools.
6. Cran engine until maximum pressure is reached on gauge. Record this pressure as #1 cylinder pressure.
7. Repeat the previous step for all remaining cylinders.
8. Compression should not be less than 689 Pa (100 psi) and not vary more than 25 percent from cylinder
to cylinder.
9. If one or more cylinders have abnormally low compression pressures, repeat the compression test.
10. If the same cylinder or cylinders repeat an abnormally low reading on the second compression test, it
could indicate the existence of a problem in the cylinder in question. The recommended compression
pressures are to be used only as a guide to diagnosing engine problems. An engine should not be
disassembled to determine the cause of low compression unless some malfunction is present.
CYLINDER CO BUSTION PRESSURE LEAKAGE TEST
The combustion pressure lea age test provides an accurate means for determining engine condition.
Combustion pressure lea age testing will detect:
Exhaust and inta e valve lea s (improper seating).
Lea s between adjacent cylinders or into water jac et.
Any causes for combustion/compression pressure loss.
Chec the coolant level and fill as required. DO NOT install the pressure cap.
Start and operate the engine until it attains normal operating temperature, then turn the engine OFF.
Clean spar plug recesses with compressed air.
WARNING: DO NOT REMOVE THE RESSURE CA WITH THE SYSTEM HOT AND
UNDER RESSURE BECAUSE SERIOUS BURNS FROM COOLANT CAN
OCCUR.
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Remove the spar plugs.
Remove the oil filler cap.
Remove the air cleaner.
Calibrate the tester according to the manufacturer's instructions. The shop air source for testing should maintain
483 Pa (70 psi) minimum, 1,379 Pa (200 psi) maximum, with 552 Pa (80 psi) recommended.
Perform the test procedures on each cylinder according to the tester manufacturer's instructions. While testing,
listen for pressurized air escaping through the throttle body, tailpipe and oil filler cap opening. Chec for
bubbles in the coolant.
All gauge pressure indications should be equal, with no more than 25% lea age per cylinder.
FOR EXA PLE: At 552 Pa (80 psi) input pressure, a minimum of 414 Pa (60 psi) should be maintained in
the cylinder.
STANDARD ROCEDURE
ENGINE GASKET SURFACE PREPARATION
Fig. 2: PROPER TOOL USAGE FOR SURFACE PREPARATION
Courtesy of CHRYSLER LLC
To ensure engine gas et sealing, proper surface preparation must be performed, especially with the use of
aluminum engine components and multi-layer steel cylinder head gas ets.
Never use the following to clean gas et surfaces:

Metal scraper (1).
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Abrasive pad or paper to clean cylinder bloc and head.
High speed power tool with an abrasive pad or a wire brush (2,3).
Fig. 3: PROPER TOOL USAGE FOR SURFACE PREPARATION
Courtesy of CHRYSLER LLC
Only use the following for cleaning gas et surfaces:
Solvent or a commercially available gas et remover
Plastic or wood scraper (4).
Sealing surfaces must be free of grease or oil residue. Clean surfaces with Mopar® bra e parts cleaner (or
equivalent).
EASURING BEARING CLEARANCE USING PLASTIGAGE
NOTE: Multi-Layer Steel (MLS) head gaskets require a scratch free sealing surface.
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Fig. 4: Plastigage Placed in Lower Shell-Typical
Courtesy of CHRYSLER LLC
Engine cran shaft bearing clearances can be determined by use of Plastigage or equivalent. The following is the
recommended procedure for the use of Plastigage:
1. Remove oil film from surface to be chec ed. Plastigage is soluble in oil.
2. Place a piece of Plastigage across the entire width of the bearing shell in the cap approximately 6.35 mm
(1/4 in.) off center and away from the oil holes . (In addition, suspected areas can be chec ed by placing
the Plastigage in the suspected area). Torque the bearing cap/bed plate bolts of the bearing being chec ed
to the proper specifications.
3. Remove the bearing cap and compare the width of the flattened Plastigage with the metric scale provided
on the pac age. Locate the band closest to the same width. This band shows the amount of clearance in
thousandths of a millimeter. Differences in readings between the ends indicate the amount of taper
present. Record all readings ta en. Compare the clearance measurements to specifications found in the
engine specifications table. See Engine - Specifications. Plastigage generally is accompanied by two
scales. One scale is in inches, the other is a metric scale.
4. Install the proper cran shaft bearings to achieve the specified bearing clearances.
FOR -IN-PLACE GASKETS AND SEALERS
There are numerous places where form-in-place gas ets are used on the engine. Care must be ta en when
applying form-in-place gas ets to assure obtaining the desired results.Do not use form-in-place gasket
material unless specified. Bead size, continuity, and location are of great importance. Too thin a bead can
result in lea age while too much can result in spill-over which can brea off and obstruct fluid feed lines. A
continuous bead of the proper width is essential to obtain a lea -free gas et.
1 - PLASTIGAGE
NOTE: lastigage is available in a variety of clearance ranges. Use the most
appropriate range for the specifications you are checking.
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There are numerous types of form
-
in
-
place gas et materials that are used in the engine area. Mopar
®
Engine
RTV GEN II, Mopar® ATF-RTV, and Mopar® Gas et Ma er gas et materials, each have different properties
and can not be used in place of the other.
OPAR® ENGINE RTV GEN II is used to seal components exposed to engine oil. This material is a
specially designed blac silicone rubber RTV that retains adhesion and sealing properties when exposed to
engine oil. Moisture in the air causes the material to cure. This material is available in three ounce tubes and has
a shelf life of one year. After one year this material will not properly cure. Always inspect the pac age for the
expiration date before use.
OPAR® ATF RTV is a specifically designed blac silicone rubber RTV that retains adhesion and sealing
properties to seal components exposed to automatic transmission fluid, engine coolants, and moisture. This
material is available in three ounce tubes and has a shelf life of one year. After one year this material will not
properly cure. Always inspect the pac age for the expiration date before use.
OPAR® GASKET AKER is an anaerobic type gas et material. The material cures in the absence of air
when squeezed between two metallic surfaces. It will not cure if left in the uncovered tube. The anaerobic
material is for use between two machined surfaces. Do not use on flexible metal flanges.
OPAR® BED PLATE SEALANT is a unique (green-in-color) anaerobic type gas et material that is
specially made to seal the area between the bed plate and cylinder bloc without disturbing the bearing
clearance or alignment of these components. The material cures slowly in the absence of air when torqued
between two metallic surfaces, and will rapidly cure when heat is applied.
OPAR® GASKET SEALANT is a slow drying, permanently soft sealer. This material is recommended for
sealing threaded fittings and gas ets against lea age of oil and coolant. Can be used on threaded and machined
parts under all temperatures. This material is used on engines with multi-layer steel (MLS) cylinder head
gas ets. This material also will prevent corrosion. Mopar® Gas et Sealant is available in a 13 oz. aerosol can or
4oz./16 oz. can w/applicator.
SEALER APPLICATION
Mopar® Gas et Ma er material should be applied sparingly 1 mm (0.040 in.) diameter or less of sealant to one
gas et surface. Be certain the material surrounds each mounting hole. Excess material can easily be wiped off.
Components should be torqued in place within 15 minutes. The use of a locating dowel is recommended during
assembly to prevent smearing material off the location.
Mopar® Engine RTV GEN II or ATF RTV gas et material should be applied in a continuous bead
approximately 3 mm (0.120 in.) in diameter. All mounting holes must be circled. For corner sealing, a 3.17 or
6.35 mm (1/8 or 1/4 in.) drop is placed in the center of the gas et contact area. Uncured sealant may be removed
with a shop towel. Components should be torqued in place while the sealant is still wet to the touch (within 10
minutes). The usage of a locating dowel is recommended during assembly to prevent smearing material off the
location.
Mopar® Gas et Sealant in an aerosol can should be applied using a thin, even coat sprayed completely over
both surfaces to be joined, and both sides of a gas et. Then proceed with assembly. Material in a can
w/applicator can be brushed on evenly over the sealing surfaces. Material in an aerosol can should be used on
engines with multi-layer steel gas ets.
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HYDROSTATIC LOCKED ENGINE
When an engine is suspected to be hydrostatically loc ed, regardless of what caused the problem, the following
steps should be used.
1. Inspect air cleaner, induction system and inta e manifold to insure system is dry and clear of foreign
material.
2. Remove negative battery cable.
3. Place a shop towel around the spar plugs when removing them from the engine. This will catch any fluid
that may possibly be in the cylinder under pressure.
4. With all spar plugs removed, rotate engine cran shaft using a brea er bar and soc et.
5. Identify the fluid in the cylinder(s) (i.e., coolant, fuel, oil or other).
6. Ma e sure all fluid has been removed from the cylinders. Inspect engine for damage (i.e., connecting
rods, pistons, valves, etc.)
7. Repair engine or components as necessary to prevent this problem from re-occurring.
8. Install new spar plugs.
9. Drain engine oil and remove oil filter.
10. Install a new oil filter.
11. Fill engine with specified amount of approved oil.
12. Connect negative battery cable.
13. Start engine and chec for any lea s.
REPAIR OF DA AGED OR WORN THREADS
Damaged or worn threads (excluding spar plug and camshaft bearing cap attaching threads) can be repaired.
Essentially, this repair consists of drilling out worn or damaged threads, tapping the hole with a special Heli-
Coil Tap, (or equivalent) and installing an insert into the tapped hole. This brings the hole bac to its original
thread size.
Heli-Coil tools and inserts are readily available from automotive parts jobbers.
ENGINE CORE AND OIL GALLERY PLUGS
CAUTION: DO NOT use starter motor to rotate the engine, severe damage may occur.
CAUTION: Squirt approximately one teaspoon of oil into the cylinders, rotate
engine to lubricate the cylinder walls to prevent damage on restart.
CAUTION: Be sure that the tapped holes maintain the original center line.
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Fig. 5: Core Hole Plug Removal
Courtesy of CHRYSLER LLC
Using a blunt tool such as a drift and a hammer, stri e the bottom edge of the cup plug. With the cup plug
rotated, grasp firmly with pliers or other suitable tool and remove plug .
Thoroughly clean inside of cup plug hole in cylinder bloc or head. Be sure to remove old sealer. Lightly coat
inside of cup plug hole with Mopar® Stud and Bearing Mount. Ma e certain the new plug is cleaned of all oil
or grease. Using proper drive plug, drive plug into hole so that the sharp edge of the plug is at least 0.5 mm
(0.020 in.) inside the lead-in chamfer.
It is not necessary to wait for curing of the sealant. The cooling system can be refilled and the vehicle placed in
service immediately.
REMOVAL
RE OVAL
1 - CYLINDER BLOCK
2 - REMOVE PLUG WITH PLIERS
3 - STRIKE HERE WITH HAMMER
4 - DRIFT PUNCH
5 - CUP PLUG
CAUTION: Do not drive cup plug into the casting as restricted cooling can result and
cause serious engine problems.
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Fig. 6: Hose Assembly & IAT Sensor
Courtesy of CHRYSLER LLC
1. Perform fuel pressure release procedure. Refer to Fuel System - Standard Procedure .
2. Disconnect negative battery cable.
3. Disconnect the Inlet Air Temp Sensor (IAT) (2), and remove air cleaner hose (1) and housing.
Fig. 7: THROTTLE BODY 3.8L
Courtesy of CHRYSLER LLC
2010 Jeep Wrangler Sport
2010 ENGINE 3.8L - Service Information - Wrangler
viernes, 1 de oct bre de 2021 05:18:29 p. m. Page 15 © 2011 Mitchell Repair Information Company, LLC.

4. Evacuate and recover the air conditioning.
5. Disconnect the throttle control connectors (3) from the throttle body.
Fig. 8: PCV VALVE LOCATION 3.8L
Courtesy of CHRYSLER LLC
6. Disconnect the PCV hose (1) at the left cylinder head cover.
Fig. 9: FRONT SPLASH SHIELD
Courtesy of CHRYSLER LLC
2010 Jeep Wrangler Sport
2010 ENGINE 3.8L - Service Information - Wrangler
viernes, 1 de oct bre de 2021 05:18:29 p. m. Page 16 © 2011 Mitchell Repair Information Company, LLC.

7. Remove the front splash shield (1).
8. Drain the cooling system.
9. Disconnect the upper radiator hose from the thermostat housing and the lower radiator hose from the
radiator.
10. Disconnect the heater hoses and coolant reservoir hose.
Fig. 10: GENERATOR ELECTRICAL CONNECTORS 3.8L
Courtesy of CHRYSLER LLC
11.
Disconnect the generator electrical connectors (1, 2).
2010 Jeep Wrangler Sport
2010 ENGINE 3.8L - Service Information - Wrangler
viernes, 1 de oct bre de 2021 05:18:29 p. m. Page 17 © 2011 Mitchell Repair Information Company, LLC.

Fig. 11: AP SENSOR 3.8L
Courtesy of CHRYSLER LLC
12. Disconnect the throttle position (TP), idle air control (IAC) motor, oxygen (HO2), cam position (CMP),
manifold absolute pressure (MAP) (2) and the two engine wiring harness connectors. Free the harness
from the cover studs and set harness aside.
13. Disconnect the purge solenoid harness connector.
Fig. 12: EGR TUBE FLANGE
Courtesy of CHRYSLER LLC
2010 Jeep Wrangler Sport
2010 ENGINE 3.8L - Service Information - Wrangler
viernes, 1 de oct bre de 2021 05:18:29 p. m. Page 18 © 2011 Mitchell Repair Information Company, LLC.

14. Disconnect the EVAP hose from the throttle body.
15. Remove the EGR tube (1). Refer to Emissions Control/Exhaust Gas Recirculation/VALVE, Exhaust
Gas Recirculation (EGR) - Removal .
Fig. 13: GENERATOR OUNTING 3.8L
Courtesy of CHRYSLER LLC
16. Remove the drive belts.
17. Remove the generator (3).
2010 Jeep Wrangler Sport
2010 ENGINE 3.8L - Service Information - Wrangler
viernes, 1 de oct bre de 2021 05:18:29 p. m. Page 19 © 2011 Mitchell Repair Information Company, LLC.

Fig. 14: FUEL RAIL 3.8L
Courtesy of CHRYSLER LLC
18. Disconnect the fuel line from fuel rail (4).
19. Remove engine wiring harness retainer from left cylinder head cover and oil level indicator tube.
Fig. 15: AP SENSOR 3.8L
Courtesy of CHRYSLER LLC
20. Disconnect the noc sensor wiring harness connector.
21. Remove the upper inta e manifold (3).
2010 Jeep Wrangler Sport
2010 ENGINE 3.8L - Service Information - Wrangler
viernes, 1 de oct bre de 2021 05:18:29 p. m. Page 20 © 2011 Mitchell Repair Information Company, LLC.