The FRONT CRANK pulley on the 2.1 Liter motor underwent a design change to strengthen it. The pulley also requires the replacement of the aperture ring that bolts onto the back part of the pulley, for the ignition primary signal. If your belts are screaming and they are tight ... the chances are the Front Crank Pulley is coming apart
First step is to remove the A/C and power steering belts. Loosen the four 10 mm headed bolts that hold the Water Pump Pulley on. Remove the belts on that pulley and then remove the four bolts.
Remove the outer pulley on the crank pulley by removing the three 10 mm bolts securing it. It is a cadmium pulley and the rest of the crank pulley is made together. I use a 1/4 inch flex head ratchet with a shallow 10 mm socket and work from up top with a remote starter switch to bump the motor over to get the pulley bolts where I want them. Its a tight fit.
Now comes the fun part, breaking the crank pulley bolt loose. The bolt is a 30 mm on 81 - 90 900s. It is a 27 mm on 90 and up cars. I use a long breaker bar and go at the bolt from the bottom. Get the socket and bar on the bolt, routing them so that they will not contact the power steering lines or the rack. The engine turns clockwise when cranking, so extend the bar to the left. Pushing the button on the remote starter switch will slam the breaker bar against the frame of the car and usually gets the bolt loose. Several attempts might have to be made. Make sure the breaker bar is clear of anything it might hit and damage and that the socket is on the bolt well after each attempt. I have never seen this fail to remove a bolt or damage anything if care is used. Once the bolt is loose, the pulley usually slides off the crankshaft real easily. A puller is not needed. The original white seal usually comes with it. There is a flywheel locking tool part number 8393993 if you have problems with the bolt. I have had some older pulley bolts that someone red loctited on. These can be very stubborn. I had to fire up the torch and put the flame dead center of the bolt for a short time. Sometimes it takes several attempts. Sooner or later it finally loosens.
Its also a wise idea to disable the ignition system while dealing with this bolt as you don't want the motor to start with the breaker bar attached!
Once this deep, it is a good idea to go ahead and remove the oil pump and replace its O-ring. The o ring is soft and pliable when new. As it ages, it hardens and shrinks and looses its ability to seal. Remove the 10 mm bolts and the two 12 or 13 mm bolts securing it to the timing cover. Later model cars have a crank shaft sensor mounted to the oil pump housing. Remove the two 20 torx holding it to the pump and swing it up and out of harms way. Be sure to reinstall it and use blue Loctite on the torx when reinstalling. There are two line up dowles in the timing cover for the oil pump. They will make the pump harder to remove, but they are necessary for proper alignment of the pump. Carefully use a flat screwdriver to persuade the pump off the studs, but take care not to damage the sealing surfaces. Walk the pump off the studs, a little on each side at a time. When it is off, remove the gears and clean it all well. A pot scrubber should be used to polish the crank pulley on its sealing surface. Clean the timing cover gently as well as the sealing surface of the pump. We use a square piece of a thick mirror and 220 grit emery paper to wet sand the sealing surface of the pump. This will show if the pump is flat and also tightens up the seal just a tad. While sanding it gently on the flat surface, you can see if the whole surface is touching the flat surface by the sanding marks. When the whole surface shows swirl marks, the sanding is done. This is not a necessary step, but a helpful one if you have a flat piece of glass handy. I do both sides of the big gear and the front side of the smaller center gear enough to put a cross hatch on them too. This helps bring the oil pump clearances up to new standards and ensures optimal pressure. Then, after again cleaning the pump well, install the new seal in the pump. It should fit flush with the outer part of the pump housing. Make sure the tensioning spring on the seal lip stays in place. I use spray adhesive in the grove for the O-ring to hold it while reassembling. Spray the groove sparingly then insert the new o ring and let it dry a few minutes, making sure it stays home. Then clean and reinstall the gears. Note that the center (smaller) gear only goes one way, so its machined surface goes into the pump. The larger gear has a triangular small mark on it that should face you when you look at the pump from behind. Then IMPORTANT: Pack the gear area of the pump with Vaseline or a clean high quality grease to ensure the pump is lubricated and primes when you crank it. Install the alignment dowels in the timing cover. Carefully align the center gear with one of the slots in the timing gear on the crank and the two line up dowels with the holes in the pump. Make sure the pump goes all the way flat against the timing cover and that the o ring is not disturbed before tightening any bolts. Reinstall all the bolts and torque evenly to 6-8 ft/lbs on the small ones and 14-16 ft/lbs on the two larger ones.
Note that the pulley is held from turning by a key way on the crankshaft. When reinstalling the crank pulley, lube the inside and outside of the pulley's sealing/mounting surfaces with Vaseline and carefully reinstall it, making sure its notch lines up and slips over the key way. Do not run the pulley up with the bolt, it should slide right on if it is lined up properly. Reinstall the the crank bolt with several drops of blue loctite and torque to _____ Ft/Lbs working from up top. I remove the side bolt on the plastic clutch cover, pry it to the side and use a medium size needle nose vice grip to bite on the ring gear of the flywheel. On tightening it jams against the clutch housing and locks the crank in place.
Before I put the belts back on I always make sure there is at least 4 quarts of oil in the motor, start the motor and make sure the oil light goes out and leak check. Put the belts back on and allow the engine to reach operating temp, then change the engine oil and filter.
This job requires a fair amount of patience and skill along with the proper tools.