Dodge Neon / Neon SRT-4. Manual — part 255
AIR CLEANER HOUSING
REMOVAL
(1) Disconnect clean air hose from air cleaner
housing (Fig. 17).
(2) Disconnect ambient air temperature sensor
(Fig. 17).
(3) Remove turbocharger solenoid bracket mount-
ing screws (Fig. 17). Reposition turbocharger solenoid
bracket.
(4) Disconnect make-up air hose from the side of
air cleaner housing.
(5) Dislodge wiring harness clips on the side of the
air cleaner housing.
(6) Remove air cleaner housing mounting screw
and nut (Fig. 17).
(7) Pull air cleaner housing straight up to remove.
INSTALLATION
(1) Install air cleaner housing. Make sure that it is
on the battery tray tab in the back and on the stud
on the side.
(2) Install the nut and screw for air cleaner hous-
ing (Fig. 17). Tighten fasteners to 7.3 N·m (65 in.
lbs.).
(3) Insert wiring harness clips on the side of the
air cleaner housing.
(4) Connect make-up air hose to the side of air
cleaner housing.
(5) Install turbocharger solenoid bracket mounting
screws (Fig. 17).
(6) Connect ambient air temperature sensor (Fig.
17).
(7) Connect clean air hose to air cleaner housing
(Fig. 17).
CYLINDER HEAD
DESCRIPTION
The cross flow designed, aluminum cylinder head
contains dual over-head camshafts with four valves
per cylinder (Fig. 18). The valves are arranged in two
in-line banks. The intake valves face toward the
front of the vehicle. The exhaust valves face the dash
panel. The cylinder head incorporates powdered
metal valve guides and seats. The cylinder head is
sealed to the block using a multi-layer steel head
gasket and retaining bolts.
Integral oil galleries provide lubrication passages
to the hydraulic lash adjusters, camshafts, and valve
mechanisms.
Fig. 17 Air Cleaner Housing Mounting
1 - CLEAN AIR HOSE
2 - SOLENOID MOUNTING BRACKET SCREWS
3 - AMBIENT AIR TEMPERATURE SENSOR
4 - AIR CLEANER HOUSING MOUNTING NUT
5 - AIR CLEANER HOUSING MOUNTING SCREW
Fig. 18 Cylinder Head and Camshafts
1 - CAMSHAFT BEARING CAPS
2 - PLUG
3 - CAMSHAFT
4 - CYLINDER HEAD
5 - CAMSHAFT OIL SEAL
9 - 114
ENGINE 2.4L DOHC TURBO
PL/SRT-4
DIAGNOSIS AND TESTING
CYLINDER HEAD GASKET
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
• Loss of engine power
• Engine misfiring
• Poor fuel economy
Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
• Engine overheating
• Loss of coolant
• Excessive steam (white smoke) emitting from
exhaust
• Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test (Refer
to 9 - ENGINE - DIAGNOSIS AND TESTING). An
engine cylinder head gasket leaking between adja-
cent cylinders will result in approximately a 50–70%
reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE
PRESSURE
BUILT
UP,
BY
CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester’s pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
REMOVAL - CYLINDER HEAD
(1) Perform fuel system pressure release procedure
before attempting any repairs (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY - STANDARD
PROCEDURE).
(2) Disconnect negative cable from battery.
(3) Remove clean air hose and air cleaner housing
(Refer to 9 - ENGINE/AIR INTAKE SYSTEM/AIR
CLEANER HOUSING - REMOVAL).
(4) Drain cooling system (Refer to 7 - COOLING/
ENGINE - STANDARD PROCEDURE).
(5) Disconnect the fuel supply line quick-connect at
the fuel rail assembly (Refer to 14 - FUEL SYSTEM/
FUEL DELIVERY/QUICK CONNECT FITTING -
STANDARD PROCEDURE).
(6) Remove heater tube support bracket from cyl-
inder head.
(7) Remove upper radiator hose. Disconnect heater
hoses from thermostat housing.
(8) Disconnect engine coolant temperature sensor
connector.
(9) Remove accessory drive belts (Refer to 7 -
COOLING/ACCESSORY
DRIVE/DRIVE
BELTS
-
REMOVAL).
(10) Disconnect exhaust pipe from manifold.
(11) Remove turbocharger heat shields (Fig. 19)
(12) Remove elbow support bracket (Fig. 19)
(13) Remove turbocharger support bracket (Fig.
19)
(14) Remove elbow (Fig. 19)
(15) Remove
oil
return
tube
(Refer
to
11
-
EXHAUST
SYSTEM/TURBOCHARGER
SYSTEM/
LINES AND HOSES - REMOVAL) (Fig. 20).
(16) Remove oil supply line (Fig. 20).
(17) Remove coolant supply line (Fig. 20).
(18) Remove coolant return line (Fig. 20).
(19) Disconnect
ignition
coil
wiring
connector.
Remove ignition coil and plug wires from engine.
(20) Disconnect camshaft position sensor wiring
connector.
(21) Remove timing belt and camshaft sprockets
(Refer to 9 - ENGINE/VALVE TIMING/TIMING
BELT AND SPROCKETS - REMOVAL).
(22) Remove timing belt idler pulley and rear tim-
ing belt cover (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT COVER(S) - REMOVAL).
(23) Remove cylinder head cover (Refer to 9 -
ENGINE/CYLINDER
HEAD/CYLINDER
HEAD
COVER - REMOVAL).
PL/SRT-4
ENGINE 2.4L DOHC TURBO
9 - 115
CYLINDER HEAD (Continued)
(24) Remove camshafts (Refer to 9 - ENGINE/
CYLINDER HEAD/CAMSHAFT(S) - REMOVAL).
(25) Remove rocker arms.
(26) Remove cylinder head bolts in the reverse
sequence of tightening (Fig. 26).
(27) Remove cylinder head from engine block.
(28) Inspect and clean cylinder head and block
sealing surfaces. Refer to Cleaning and Inspection in
this section for procedures.
NOTE: Ensure cylinder head bolt holes in the block
are clean, dry (free of residual oil or coolant), and
threads are not damaged.
CLEANING
To ensure engine gasket sealing, proper surface
preparation must be performed, especially with the
use of aluminum engine components and multi-layer
steel cylinder head gaskets.
NOTE: Multi-Layer Steel (MLS) head gaskets require
a scratch free sealing surface.
Remove all gasket material from cylinder head and
block (Refer to 9 - ENGINE - STANDARD PROCE-
DURE). Be careful not to gouge or scratch the alumi-
num head sealing surface.
Clean all engine oil passages.
INSPECTION
(1)
Cylinder head must be flat within 0.1 mm
(0.004 in.) (Fig. 21).
(2)
Inspect camshaft bearing journals for scoring.
(3) Remove carbon and varnish deposits from
inside of valve guides with a reliable guide cleaner.
Fig. 19 Turbocharger Brackets and Heat Shields
1 - UPPER/LOWER HEAT SHIELDS
2 - TURBOCHARGER SUPPORT BRACKET
3 - ELBOW
4 - ELBOW SUPPORT BRACKET
Fig. 20 Turbocharger Lines and Hoses
1 - OIL SUPPLY LINE
2 - COOLANT RETURN LINE
3 - COOLANT SUPPLY LINE
4 - OIL RETURN TUBE
Fig. 21 Checking Cylinder Head Flatness
1 - FEELER GAUGE
2 - STRAIGHT EDGE
9 - 116
ENGINE 2.4L DOHC TURBO
PL/SRT-4
CYLINDER HEAD (Continued)
(4) Using a small hole gauge and a micrometer,
measure valve guides in 3 places top, middle and bot-
tom (Fig. 22). (Refer to 9 - ENGINE - SPECIFICA-
TIONS) Replace guides if they are not within
specification.
(5) Check valve guide height (Fig. 23).
INSTALLATION - CYLINDER HEAD
NOTE: The Cylinder head bolts should be examined
BEFORE reuse. If the threads are necked down, the
bolts should be replaced (Fig. 24).
Necking can be checked by holding a scale or
straight edge against the threads. If all the threads
do not contact the scale, the bolt should be replaced.
NOTE: Head gaskets for Non-Turbo and Turbo appli-
cations are NOT interchangeable.
(1) Position the new cylinder head gasket on
engine block with the part number facing up (Fig.
25). Ensure gasket is seated over the locating dowels
in block.
(2) Position cylinder head onto engine block.
(3) Before installing the bolts, the threads should
be lightly coated with engine oil.
(4) For Non-Turbo equiped engines tighten the
cylinder head bolts in the sequence shown in (Fig.
26). Using the 4 step torque-turn method, tighten
according to the following values:
• First: All to 34 N·m (25 ft. lbs.)
• Second: All to 68 N·m (50 ft. lbs.)
• Third: All to 68 N·m (50 ft. lbs.)
CAUTION: Do not use a torque wrench for the
Fourth step.
• Fourth: Turn all bolts an additional 1/4
Turn
(5) For Turbo equiped engines tighten the cylin-
der head bolts in the sequence shown in (Fig. 26).
Using the 4 step torque-turn method, tighten accord-
ing to the following values:
Fig. 22 Checking Wear on Valve Guide—Typical
1 - TOP
2 - MIDDLE
3 - BOTTOM
4 - CUT AWAY VIEW OF VALVE GUIDE MEASUREMENT
LOCATIONS
Fig. 23 Valve Guide Height
1 - VALVE GUIDE
2 - 13.25 - 13.75 MM (0.521 - 0.541 IN.)
3 - SPRING SEAT
Fig. 24 Checking Bolts for Stretching (Necking)
1 - STRETCHED BOLT
2 - THREADS ARE NOT STRAIGHT ON LINE
3 - THREADS ARE STRAIGHT ON LINE
4 - UNSTRETCHED BOLT
Fig. 25 Cylinder Head Gasket Positioning
1 - PART NUMBER FACES UP
2 - NO. 1 CYLINDER
PL/SRT-4
ENGINE 2.4L DOHC TURBO
9 - 117
CYLINDER HEAD (Continued)
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