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Fig. 2 Cylinder Head Cover and Curtain

CYLINDER HEAD COVER AND CURTAIN

A curtain aiding air/oil separation is installed on the cylinder head below the cylinder head cover (Figs. 1 and 2).

REMOVAL

(1)Remove the cylinder head cover bolts (Fig. 2).

(2)Remove cylinder head cover and curtain from cylinder head. Do not misplace the rubber bumpers on curtain.

CLEANING

Before installation, clean cylinder head and cover mating surfaces. Make certain the rails are flat.

CURTAIN INSTALLATION

Install curtain manifold side first with cutouts over cam towers and contacting cylinder head floor, then press opposite distributor side into position below cylinder head rail.

Fig. 3 Cylinder Head Valve Cover Rail Sealing

Curtain is retained in position with rubber bumpers (Fig. 1).

COVER SEALING AND INSTALLATION

Before installation, clean cylinder head and cover mating surfaces. Make certain rails are flat.

(1)Install new end seals on valve cover.

(2)Apply form-in-place Mopar Silicone Rubber Adhesive Sealant or equivalent gasket material to cylinder head cover rail (Fig. 3). Refer to procedure detailed in form-in-place gasket section of Standard Service Procedures, in this Group.

CAUTION: Do not allow oil or solvents to contact the timing belt as they can deteriorate the rubber and cause tooth skipping.

(3) Install curtain, cover and end seal assembly to head and tighten to 12 Nzm (105 in. lbs.) torque.

CYLINDER HEAD COMPONENTS−IN-VEHICLE SERVICE

Removal and installation of cylinder head or camshaft require separation of camshaft timing sprocket from camshaft. To maintain camshaft, intermediate shaft, and crankshaft timing during service procedures, the timing belt is left indexed on the sprocket while the assembly is suspended under light tension (Fig. 4).

When removing the sprocket from the camshaft, you must maintain adequate tension on the sprocket and belt assembly to prevent the belt from disengaging with the intermediate or crankshaft timing sprocket. Refer to Timing System and Seals for re-

Fig. 5 Engine Sprocket Timing

moval and installation of camshaft sprocket procedure and to Camshaft Service for removal and installation of camshaft procedures.

CAUTION: Failure to maintain adequate tension on camshaft, intermediate, and crankshaft sprocket belt can result in lost engine timing. If timing is lost, refer to Timing System and Seals and (Fig. 4).

CAMSHAFT SERVICE

Refer to TIMING SYSTEM AND SEALS for cam-

shaft timing belt and sprocket removal and installation, and CYLINDER HEAD In Vehicle Service.

REMOVAL

(1)Remove the cylinder head cover and curtain.

(2)Mark rocker arms for reinstallation in the same position (Fig. 6).

(3)Loosen camshaft bearing cap screws several revolutions (Fig. 7).

(4)Jar camshaft at rear of cam to loosen (break free) the bearing caps. Use a soft faced mallet.

CAUTION: Care should be exercised not to cock the camshaft during removal. Cocking of the camshaft could cause damage to the cam or bearing thrust surfaces.

(5) Remove screws and caps such that cam does not cock.

INSPECTION

Check bearing cap and oil feed holes for blockage. Inspect bearing cap and cylinder head journals for wear and/or oversize, Refer to CYLINDER HEAD,

Inspect and Specifications.

Fig. 7 Camshaft Cap Removal Sequence

Fig. 8 Camshaft

Chamshaft bearing journals and lobe wear. Lobe wear should not exceed .25mm (.010 inch). To mea-

Fig. 9 Camshaft End Play

sure cam lobe wear (Fig. 8), measure lobe diameter in two places at the largest diameter (over the nose). Take first reading with micrometer in unworn area at the edge of the lobe. Take second reading in the worn area where rocker arm contacts the lobe. Subtract second reading from the first. The difference is the cam lobe wear.

CAMSHAFT END PLAY

(1)Oil camshaft journals and install camshaft without cam followers. Tighten screws to specified torque.

(2)Using a suitable tool, move camshaft as far rearward as it will go.

(3)Zero dial indicator (Fig. 9).

(4)Move camshaft as far forward as it will go.

(5)End play travel: 0.13 - 0.33mm (0.005 - 0.013 inch.).

(6)Remove bearing caps and camshaft.

INSTALLATION

(1)Install cam followers in correct order as removed.

(2)Align camshaft bearing caps in proper sequence with Cap No. 1 at timing belt end and Cap No. 5 at transmission end. Arrows on Caps No. 1, 2, 3, 4 must point toward timing belt to prevent cap breaking (Fig. 11).

(3)Apply Mopar Gasket Maker to No. 1 and No. 5 bearing cap (Fig. 10).

(4)Caps must be installed before camshaft seals are installed.

LASH ADJUSTER (TAPPET) NOISE

A tappet-like noise may be produced from several items. Refer to Lash Adjuster and Tappet Noise - Diagnosis in Standard Service Procedures, this Group.

Fig. 10 Cam Tower Cap Sealing

Fig. 11 Camshaft Bearing Caps Installation

VALVE COMPONENTS REPLACE−CYLINDER HEAD NOT REMOVED

ROCKER ARM AND HYDRAULIC LASH ADJUSTER

REMOVAL

(1)Remove valve cover.

(2)For each rocker arm, rotate cam until base circle is in contact with rocker arm. Depress valve spring using Special Tool C-4682 (Fig. 12) and slide rocker arm out. Keep rocker arms in order for reassembly.

(3)Remove hydraulic lash adjuster.

INSTALLATION

(1)Install hydraulic lash adjuster making sure that adjusters are at least partially full of oil. This is indicated by little or no plunger travel when the lash adjuster is depressed.

(2)Rotate cam until base circle is in contact position with rocker arm. Depress valve spring with Special Tool C-4682 (Fig. 12) and slide rocker arm in place. Keep rockers in order. It is possible for the

Fig. 12 Removing and Installing Valve Spring

valve spring retainer locks to become dislocated when depressing the valve spring. Check and make sure the locks are in their proper location.

(3) Install valve cover as previously outlined in this section.

VALVE SPRINGS AND VALVE STEM SEALS

REMOVAL

(1)Remove rocker arms as previously outlined in this section.

(2)Rotate crankshaft until piston is at TDC on compression.

(3)With air hose attached to adapter tool installed in spark plug hole, apply 90-120 psi air pressure.

(4)Using Special Tool C-4682 (Fig. 12) compress valve springs and remove valve locks.

(5)Remove valve spring.

(6)Remove valve stem seal by gently prying side- to-side with a screwdriver blade. Once dislodged from guide post, seal may be easily removed.

INSTALLATION

(1)Install valve seals (Fig. 13) as outlined in step

(2)of Valve Gear Reassembly - After Valve Service in this section.

(2)Using Special Tool C-4682 compress valve springs only enough to install locks. Correct alignment of tool is necessary to avoid nicking valve stems (air pressure required), piston at TDC.

(3)Install rocker arms as previously outlined in this section.

CYLINDER HEAD

REMOVAL

(1)Perform fuel system pressure release procedure before attempting any repairs. Refer to Fuel System Group 14.

(2)Disconnect negative battery cable. Drain cooling system. Refer to Cooling System, Group 7.

Fig. 13 Valve Stem Seals

(3)Remove air cleaner and disconnect all vacuum lines, electrical wiring and fuel lines from throttle body.

(4)Remove throttle linkage.

(5)Loosen power steering pump and remove belt.

(6)Remove power brake vacuum hose from intake manifold.

(7)Remove water hoses from water crossover.

(8)Raise vehicle and remove exhaust pipe from manifold.

(9)Remove power steering pump assembly and set aside.

(10)Disconnect coil wiring connector and coil wire from coil.

(11)Disconnect dipstick tube from thermostat housing and ROTATE bracket from stud. DO NOT bend the bracket.

(12)See Solid Mount Compressor Bracket in STANDARD SERVICE PROCEDURES, this Group.

(13)Remove cylinder head bolts.

INSPECT HEAD AND CAMSHAFT BEARING JOURNALS

Fig. 14 Checking Cylinder Head Flatness

(1) Cylinder head must be flat within 0.1mm (.004 inch) (Fig. 14).

(2) Inspect camshaft journals for scoring and journal caps for oversize markings. When servicing cylinder head or camshaft, it is necessary to be certain that oversized camshafts are used only in oversized heads. Identify oversize components as follows:

Cylinder Head: Top of bearing caps painted green and O/SJ stamped rearward of oil gallery plug on end of head.

Camshaft: Barrel of camshaft painted green and O/SJ stamped on end of shaft.

CLEANING

Remove all gasket material from cylinder head and block. Be careful not to gouge or scratch aluminum head sealing surface.

INSTALLING

CAUTION: 2.5L turbo I engine head gasket is NOT the same as that used for prior years 2.2L turbo I engine (Fig. 15).

CAUTION: Head bolt diameter is 11mm. These bolts are identified with 11 on the head of the bolt. 10mm bolts will thread into the 11mm hole but will strip the cylinder block bolt hole.

Since the Cylinder head bolts are torqued using a new procedure they should be examined BEFORE reuse. If the threads are necked down the bolts should be replaced (Fig. 16).

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.

Fig. 16 Checking Bolts for Stretching (Necking)

(1)Before installing the bolts the threads should be oiled with engine oil.

(2)Install both bolts in each cap finger tight, then alternately torque each bolt to assemble the cap properly.

(3)Tighten the cylinder head bolts in the sequence shown in (Fig. 17). Using the 4 step torque turn method, tighten according to the following values:

²First All to 61 Nzm (45 ft. lbs.)

²Second All to 88 Nzm (65 ft. lbs.)

²Third All (again) to 88 Nzm (65 ft. lbs.)

²Fourth + 1/4 Turn Do not torque wrench for this step.

Bolt torque after 1/4 turn should be over 90 ft. lbs. If not, replace the bolt.

(4)Rotate dipstick tube on bracket.

(5)Tighten bracket retaining nut to 23 Nzm (200 in.

lbs.)

9 - 28 2.2/2.5L ENGINES

VALVE INSPECTION

(1)Clean valves thoroughly and discard burned, warped and cracked valves.

(2)Measure valve stems for wear.

(3)If valve stems are worn more than 0.05 mm (.002 inch) replace valve.

VALVE GUIDES

(1)Remove carbon and varnish deposits from inside of valve guides with a reliable guide cleaner.

(2)Checking Valve Guide Wear:

²Insert valve with valve head positioned 10 mm (.400 inch) above cylinder head gasket surface.

²Move valve to and from the indicator (Fig. 17). The total dial indicator reading should not exceed the amount specified in (Fig. 18). Readings should be taken for lengthwise and crosswise (with respect to cylinder head) movement for each valve. Ream the guides for valves with oversize stems if dial indicator reading is excessive or if the stems are scuffed or scored.

Fig. 18 Checking Wear on Valve Guide−Typical

Fig. 19 Valve Guide Specification

(3) Service valves with oversize stems and oversize seals are available in 0.15mm, (.005 inch) 0.40mm, (.015 inch) and 0.80mm (.031 inch) oversize.

Oversize seals must be used with oversize valves.

Ä

Reamers sizes to accommodate the oversize valve stem are shown in (Fig. 18).

(4) Slowly turn reamer by hand and clean guide thoroughly before installing new valve. Do not attempt to ream the valve guides from standard directly to 0.80mm (.030 inch). Use step procedure of 0.15mm (.005 inch), 0.40mm (.015 inch) and 0.80mm (.030 inch) so the valve guides may be reamed true in relation to the valve seat. After reaming guides, the seat runout should be measured and resurfaced if necessary. See Refacing Valves and Valve Seats.

Replace cylinder head if guide does not clean up with 0.80 mm (.030 inch) oversize reamer, or if guide is loose in cylinder head.

Fig. 20 Testing Valve Spring with Tool C-647

TESTING VALVE SPRINGS

(1)Whenever valves have been removed for inspection, reconditioning or replacement, valve springs should be tested. As an example, the compression length of the spring to be tested is 33.34mm (1-5/16 inches). Turn table of Tool C-647 until surface is in line with the 33.34mm (1-5/16 inch) mark on the threaded stud and the zero mark on the front. Place spring over stud on the table and lift compressing lever to set tone device (Fig.20). Pull on torque wrench until ping is heard. Take reading on torque wrench at this instant. Multiply this reading by two. This will give the spring load at test length. Fractional measurements are indicated on the table for finer adjustments. Refer to specifications to obtain specified height and allowable tensions. Discard the springs that do not meet specifications.

(2)Inspect each valve spring for squareness with a steel square and surface plate, test springs from both ends. If the spring is more than 1.5mm (1/16 inch) out of square, install a new spring.

REFACING VALVES AND VALVE SEATS

(1) The intake and exhaust valve seats and valve face have a 45 degree angle.

Fig. 22 Valve Dimensions

(2)Inspect the remaining margin after the valves are refaced (Fig. 23). Exhaust valves with less than 1.191mm (3/64 inch) margin and intake valves with less than .794mm (1/32 inch) margin should be discarded.

(3)When refacing valve seats, it is important that the correct size valve guide pilot be used for reseating stones. A true and complete surface must be obtained.

(4)Measure the concentricity of valve seat using a valve seat dial indicator. Total runout should not exceed .051mm (.002 inch) (total indicator reading).

(5)Inspect the valve seat with Prussian blue to determine where the valve contacts the seat. To do this, coat valve seat LIGHTLY with Prussian blue then set valve in place. Rotate the valve with light pressure. If the blue is transferred to the center of valve face, contact is satisfactory. If the blue is transferred to top edge of the valve face, lower valve seat with a 15 degrees stone. If the blue is transferred to the bottom edge of valve face raise valve seat with a 65 degrees stone.

²Intake valve seat diameter 40.45mm (1.593 inch)

²Exhaust valve seat diameter 34.84mm (1.371 inch)

Fig. 23 Refacing Intake and Exhaust Valves

(6)When seat is properly positioned the width of intake seats should be 1.75 to 2.25mm (0.69 to .088 inch). The width of the exhaust seats should be 1.50 to 2.00mm (.059 to .078 inch) (Fig. 24 Dimension 1).

(7)Check valve tip to valve spring seat dimensions after grinding to seats or faces. Grind valve tip to give 49.76 to 51.04mm (1.960 to 2.009 inch) over valve spring seat when installed in the head (Fig. 25). The valve tip diameter should be no less than 7.0mm (0.275 inch), if necessary, the tip chamfer should be reground to prevent seal damage when the valve is installed.

Fig. 24 Refacing Valve Seats

(8) Check the valve spring installed height after refacing the valve and seat (Fig. 26).