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9 - 36 2.2/2.5L ENGINES

CAMSHAFTS SERVICE

Cylinder Head must be removed from vehicle. Refer to cylinder head removal for procedure.

REMOVAL

(1)Mark rocker arms shafts for reinstallation in the same position (Fig. 1).

(2)Remove rocker arm assembly attaching bolts in sequence (Fig. 1).

(3)Remove thrust plates from rear of camshafts (Fig. 2). The intake camshaft uses a wider thrust plate than exhaust camshaft.

CAUTION: Thrust plates are not the same thickness and cannot be interchanged.

Fig. 1 Rocker Arm Shaft Removal Sequence

Fig. 2 Camshaft Thrust Plates

(4)Before camshaft can be removed from cylinder head the cam seal must be removed first. Be careful not to damage seal surface of the camshaft.

(5)Using a screwdriver place it against the side of the cam lobe push the cam out of the head. The cam seal will be pushed out by the cam (Fig. 3).

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(6) Slide the camshaft out of the cylinder head. Be careful not scratch the bearing surfaces in the head (Fig. 4).

CAUTION: Intake and Exhaust camshafts are not interchangeable.

Fig. 3 Removing Camshaft Oil Seal

Fig. 4 Camshaft−Removal or Installation

INSPECTION

Camshaft lobe wear should not exceed .25mm (.010 inch). To measure cam lobe wear (Fig. 4), 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.

INSTALLATION

(1) Lubricate camshaft journals with clean engine oil. Carefully install camshaft into the head.

CAUTION: Camshafts are not interchangeable. The intake cam has a wider thrust plate groove.

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Fig. 5 Measuring Camshaft Lobe Wear

(2)Install thrust plates and tighten retaining nuts to 6 Nzm (55 in. lbs.).

(3)Install new camshaft oil seals flush with cylinder head surface.

Using seal installing special tool C-4680.

Fig. 6 Checking Camshaft End Play

CAMSHAFT END PLAY

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

(2)Zero dial indicator (Fig. 6).

(3)Move as far forward and backward as camshaft will go.

(4)End play travel: 0.025-0.200mm (.001-.008

inch).

LASH ADJUSTER (TAPPET) NOISE

A tappet-like noise may be produced from several items. See Lash Adjuster and Tappet NoiseDIAGNOSIS in STANDARD SERVICE PROCEDURES, this Group.

2.2/2.5L ENGINES 9 - 37

VALVE COMPONENTS REPLACE−CYLINDER HEAD NOT REMOVED

ROCKER ARM AND HYDRAULIC LASH ADJUSTER

REMOVAL

(1)Remove valve cover. Refer to procedure previously outlined in this section.

(2)Remove rocker arm shaft(s) in sequence shown in (Fig. 6). Slide rocker off the shaft. Keep rocker arms in order for reassembly.

CAUTION: Check lash adjuster for loose or missing retainers before continuing service procedure.

(3) Remove hydraulic lash adjuster.

Fig. 7 Rocker Arm Shaft−Removal

Fig. 8 Rocker Arm and Lash Adjuster

Assembly−Right and Left

9 - 38 2.2/2.5L ENGINES

INSTALLATION

(1)Install rocker arm on the shaft in there original position (Fig. 9).

(2)Install hydraulic lash adjusters 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.

(3)Install rocker arm shaft assembly tighten in sequence shown in (Fig. 10).

(4)Install valve cover as previously outlined.

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(2)Remove valve retaining locks, valve spring retainers, valve stem seals and valve springs.

(3)Before removing valves, remove any burrs from valve stem lock grooves to prevent damage to the valve guides. Identify valves to insure installation in original location.

Fig. 9 Intake and Exhaust Rocker Arm Assemblies

Fig. 10 Rocker Arm Shaft−Installation

VALVE SPRINGS AND VALVE STEM SEALS

VALVE SERVICE

² CYLINDER HEAD MUST BE REMOVED TO SERVICE VALVE SPRINGS AND VALVE STEM SEALS.

VALVE AND VALVE SPRINGS

REMOVAL

(1) With cylinder head removed, compress valve springs using Valve Spring Compressor Tool C-3422-B with adopters 6537 and 6526 (Fig. 11).

Fig. 11 Valve Spring Compressor

Fig. 12 Valve Guide Specificaton

VALVE INSPECTION

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

(2)Measure valve stems for wear. Refer to (Fig. 14) for specifications.

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

VALVE GUIDES

Measure valve guides in 3 places top, middle and bottom (Fig. 13). Using a small hole gauge and a micrometer, refer to (Fig. 12) for specifications.

Replace cylinder head if guides are not within specifications.

TESTING VALVE SPRINGS

(1)Refer to Testing Valve previously described in this Group for procedure. Test springs at 36.8mm (1-7/16 to 1-15/32 in.) 1000 N 225 lbs.) 6 40 N (9 lbs.). 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 1.65mm (1/16 inch) out of square, install a new spring. Spring free length is 53.2 mm 6 .25 mm (2.094 in. 6 .010 in.)

Fig. 13 Measuring Valve Guides

Fig. 14 Valve Dimensions

REFACING VALVES AND VALVE SEATS

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

(2)Inspect the remaining margin after the valves are refaced (Fig. 11). Exhaust valves with less than 1.07mm (3/64 inch) margin and intake valves with less than 1.06mm (3/64 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 0.1 mm (.004 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 degree 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 34.0mm (1.338 inch)

²Exhaust valve seat diameter 29.4mm (1.157 inch)

Fig. 15 Refacing Intake and Exhaust Valves

Valve seats which are worn or burned can be reworked, provided that correct angle and seat width are maintained. Otherwise cylinder head must be replaced.

(6)When seat is properly positioned the width of intake seats should be 1.87mm (0.73 inch) The width of the exhaust seats should be 2.00mm (.078 inch) (Fig. 16 Dimension 1).

(7)Check valve tip for scoring, if necessary, the tip chamfer should be reground to prevent seal damage when the valve is installed.

(8)Check the valve spring installed height after refacing the valve and seat (Fig. 17).

Fig. 16 Refacing Valve Seats

VALVE GEAR REASSEMBLY AFTER VALVE SERVICE

(1)Coat valve stems with lubrication oil and insert in cylinder head.

(2)Install new valve stem seals on all valves. The valve stem seals should be pushed firmly and squarely over valve guide. The lower edge of the seal should be resting on the valve guide boss.

(3)Install valve spring seats and springs and retainers. Compress valve springs only enough to in-

9 - 40 2.2/2.5L ENGINES

stall locks, taking care not to misalign the direction of compression. Nicked valve stems may result from misalignment of the valve spring compressor.

CAUTION: When depressing the valve spring retainers with Valve Spring Compressor Tool C-3422-B with adopters 6537 and 6526 (Fig. 11) the locks can become dislocated. Check to make sure both locks are in teir correct location after removing tool.

(4)Check installed height of springs. Measurement is to be taken from the lower edge of the valve spring to its upper edge. Do not include the spring seat or retainer flange. Correct height is 44.0mm (1.73 inches). If seats have been reground an additional spring seat may be required to maintain correct installed spring height (Fig. 17).

(5)Install camshaft and rocker arms as previously described, see Camshaft-Install.

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Fig. 17 Checking Spring Installed Height