The General Motors 2.4 liter four cylinder twin cam engine debuted in 1988 and was originally developed as the Quad Four. The engine has been around for a number of years, so ample parts are available for repairs and modifications. The 2.4 liter twin cam engine delivered horsepower during an era when larger V8 engines only produced 20 horsepower more. General Motors used the engine on the Pontiac Grand AM SE as the base engine in 1999 and it was rated at 150 horsepower at 5,600 rpm with 155 foot-pounds of torque at 4,400 rpm.
Remove the coolant reservoir with a ratchet wrench and then remove the drivebelt by using a box wrench to loosen the tensioner near the alternator. A breaker bar or socket will not fit.
Support the engine from above using a Cherry picker or from below using a floor jack. Use tire chocks to chock the rear wheels. Remove the front engine mount and remove the engine mount bracket and discard the three bolts.
Take out the crankshaft pulley and set aside. Utilize a breaker bar and socket on the crankshaft pulley bolt while using another bar through a hole in the pulley to keep the pulley motionless. A tire iron will suffice as the second bar.
Use a puller that bolts to the crankshaft pulley hub that applies force to the hub so it can be pulled out.
Unscrew with a ratchet wrench all the upper timing chain cover fasteners, work from above for upper and then work from below to remove the lower fasteners. There are 22 fasteners in total.
Pull off the timing chain cover and gaskets from the housing and then slide out the oil slinger from the crankshaft. It should just slide out by hand.
Hand screw the crankshaft pulley bolt back on so you can move the crankshaft. Turn the crankshaft in the clockwise direction until the camshaft sprockets timing pin holes align with the holes in the timing chain housing. Now insert two 8-millimeter pins or bolts into the holes of the camshaft sprockets to keep this alignment. There are two marks that look like rivets on the crankshaft sprocket. These should line up with the mark on the engine block. The crankshaft sprocket keyway should point up and line with the center-line of the cylinder bores. The engine is now locked into the timed position.
Remove the three timing chain guides with your fingers or needle-nose pliers. These guides are wedged into place. They are wedged into place in four points. Just pull and they come out.
Inspect the slack in the timing and insure that the slack in the chain lies above the tensioner assembly then remove the chain tensioner mounting bolts, two of them, with a ratchet wrench. The tensioner looks like a brake shoe.
Hold the intake camshaft sprocket with snub-nose pliers and remove the sprocket bolt and washer with a ratchet wrench.
Remove the washer from the bolt and thread the bolt back into the camshaft by hand.
Remove the intake camshaft sprocket using a three-jaw puller in the three relief holes in the sprocket . Do use any tool to pry the sprocket off.
Take the chain off the shoe and then remove the tensioner and shoe assembly from the engine.
The tensioner pushes on the shoe assembly to keep tension on the chain. Replace the tensioner. Assembly is the reversal of the removal.
