Wrangler L6-4.0L VIN S (2000)
prevent the possibility of the exhaust valve from falling completely into the cylinder.
4.
Install the essential service tool valve spring compressor, MD-998772A, to the # 1 cylinder exhaust valve spring.
NOTE:
THE FOLLOWING VALVE ROTATION PROCEDURE WAS DEVELOPED WITH THE USE OF VALVE SPRING COMPRESSOR TOOL
MD-998772A. THE MD-998772A IS AN ESSENTIAL SERVICE TOOL AND PART OF THE DEALERSHIP REQUIRED TOOLS. THE
MD-998772A COMPRESSOR ENGAGES THE ENTIRE PERIMETER OF THE VALVE SPRING RETAINER, UNLIKE OTHER MAKE
VALVE SPRING COMPRESSORS.
5.
Compress the # 1 cylinder exhaust valve spring enough to gain access so that the exhaust valve can be rotated 90°. Rotate the exhaust valve 90°.
Slowly remove the compression on the exhaust valve spring. Verify that the valve keeper is properly seated to the valve stem and valve spring
retainer.
6.
The 4.0L firing order is 1 - 5 - 3 - 6 - 2 - 4. Without rotating the engine crankshaft repeat steps 3 through 5 to cylinder # 6.
7.
Rotate the engine crankshaft 1200 and repeat steps 3 through 5 to cylinders # 5 and # 2.
8.
Rotate the engine crankshaft another 1200 and repeat steps 3 through 5 to cylinders # 3 and # 4.
9.
Install all cylinder rocker arms (intake and exhausts) and retaining bridge. Make certain that the push rods are properly seated to their respective
rocker arm and lifter. Tighten the respective cylinder bridge/rocker arm cap screws to 30 Nm (21 ft. lbs.) when each cylinder piston is at top dead
center (cylinder intake and exhaust valves are closed).
10.
Install the engine cylinder head valve cover. Tighten the valve cover bolts to 10 Nm (85 in. lbs.). Refer to the appropriate vehicle Service Manual
for detailed assembly instructions.
DECARBONING COMBUSTION CHAMBER AND VALVES:
1.
Start the vehicle engine and allow the engine to reach normal operating temperature.
2.
Remove the air tube from the engine throttle body.
3.
With the engine at idle, spray the entire contents of Mopar Combustion Chamber Cleaner, p/n 04318001AB, directly into the throttle body. As the
cleaner is being ingested, allow the vehicle to "load up" with the cleaner to the point that the engine is almost stalling out. Maintain this condition
until all of the cleaner is used/ingested.
4.
Stop the engine once the entire can of cleaner has been ingested.
5.
Install the air tube to the throttle body.
6.
With the hood closed and the vehicle parked inside the garage, allow the vehicle engine to heat soak for two to three hours. This will ensure that
the engine will maintain its temperature and will allow proper solvent penetration.
7.
After engine soak, start the engine and drive the vehicle until the engine is has reached normal engine operating temperatures.
8.
If the vehicle is equipped with an automatic transmission, place the gear selector into "L" (low). If the vehicle is equipped with a manual
transmission, place the transmission into first gear.
9.
In a safe vehicle operating location that will allow the vehicle to be driven safely and at the posted speed limit, accelerate the vehicle until the
engine reaches 4500 RPM.
10.
Hold the engine speed at this RPM for 15 seconds.
11.
Slow down and in a safe location pull to the side of the road. Allow the engine to idle for five seconds.
12.
Repeat steps 9 through 11 five more times.
13.
With the vehicle at operating temperature and using any available Freeze Frame data recorded when the misfire DTC occurred, verify that the
misfire condition has been corrected.
14.
Erase any engine DTC's once the misfire condition has been corrected.
