Repair And Fix it

The thermostat on your 1999 Saturn is located on the lower front of the engine on the passengers side, just above the water pump. The thermostat controls the flow of the coolant thats needed to maintain the proper operating temperature of the engine. As the engine temperature rises, the thermostat automatically opens and allows coolant into the engine. A malfunctioning thermostat will fail to open, preventing coolant from entering the engine and causing the engine to overheat. Replacing the thermostat is a fairly simple process that requires only a few tools.

Instructions

Removing the Thermostat

1

Allow the engine to cool. Put on your safety glasses, raise the hood and remove the radiator cap to release the pressure in the hose. Disconnect the negative battery cable for added safety.

2

Remove the carburetor air cleaner and filter unit to provide for better access to the thermostat. Unscrew the cover bolt in the center cap with your hand.

3

Place a clean bucket directly under the drain bolt on the bottom of the radiator.

4

Slide underneath the Saturn on your back and loosen the drain bolt using a socket wrench. Drain just enough coolant to clear out the upper radiator hose and tighten the drain bolt. Check to see if it is clear by squeezing the hose and feeling for any remaining coolant. Repeat this step until the upper radiator hose is empty.

5

Detach the spring-type hose clamp from the upper radiator hose where it attaches to the thermostat housing. Squeeze the clamp using channel-lock pliers and slide it off of the cover. The end that connects to the radiator can remain attached.

6

Remove the two mounting bolts that secure the thermostat housing cover to the engine block, using the socket wrench. Tap the cover using a rubber mallet to break the seal. Remove the thermostat. Scrape off the old gasket using a razor, being caul not to allow any gasket debris to fall into the engine.

Installing the Thermostat

7

Test the new thermostat before installing to confirm that its working properly. Fill a deep bowl with very hot tap water. Grab the thermostat upright using the channel-lock pliers and hold it in the hot water, making sure the entire thermostat is submerged. The lower spring side of the thermostat should open immediately, indicating that it is working correctly.

8

Apply a small amount of gasket adhesive to the new gasket using your finger. Place the gasket directly onto the engine block at the thermostat opening. Be sure that the mounting holes are correctly aligned so that the thermostat will seat correctly.

9

Install the new thermostat with the spring side inserted into the engine, and caully reposition the housing cover. Do not to move or disturb the gasket. Secure the housing cover on the engine block with the two mounting bolts.

10

Reposition the carburetor air cleaner and filter. Reconnect the upper radiator hose to the thermostat cover. Secure the hose in place with the spring clamp. Inspect the hose for bulging and replace it if necessary.

11

Reconnect the negative battery cable and start the engine. Pour the drained coolant back into the radiator and allow the engine to idle for several minutes. Inspect the thermostat and hose connections for leaks.

Misfires are a common problem among cars, particularly older ones, when a lack of spark, fuel, air or compression occurs. Diagnosing and fixing a misfire takes skill because of the multiple components involved in the control of just one necessary element of combustion. Modern cars such as a 1996 Saturn have an on-board diagnostics system that can help find the source of the problem quickly if one is detected by a sensor. Misfires are characterized by a rough idle, reduction in power and poor riding comfort at speed and require immediate attention to avoid serious engine damage.

Instructions

1

Open the hood and disconnect the negative terminal from the battery using a wrench. Set it safely aside.

2

Hook up an on-board diagnostics scanner to the Saturns on-board diagnostics II port. This is usually located under the drivers steering wheel column on either side. Turn the car to accessory and enter the scan mode of the scanner. Search for codes indicating injector, fuel or air delivery failure and replace components as necessary. Also scan for oxygen sensor codes giving higher than normal readings; these indicate a possible spark delivery problem.

3

Remove the cylinder 1 spark plug with a socket set and check it for discoloration using a spark plug color chart. Dry plugs indicate a lack of fuel, while wet spark plugs indicate a lack of spark. Replace the spark plug with a new one, ensuring to coat the threads in anti-seize compound.

4

Inspect the cylinder 1 spark plug wires from the distributor to the spark plug for cracking and exposed metal. These change the resistance in the wire, causing spark failure. If replacement is necessary, order an entire set and replace all spark plug wires to maintain uniform resistivity to all cylinders. Also check the distributor for signs of wear and replace as needed.

5

Remove the cylinder 1 injector connector at the wiring harness and inspect for corrosion or wiring damage and repair as needed. Check the resistance of the injector by attaching multimeter clips to the injectors metal connectors and turning the multimeter to the 200-ohm setting. Compare with the manufacturers specification for that particular injector to ensure the electrical components are working.

6

Reinstall the cylinder 1 fuel injector clip. Remove the entire fuel rail with the injectors attached and coil wire. Turn the car over with the fuel rail off and inspect the spray pattern of the cylinder 1 injector. If a fine spray does not come from the injector, have it professionally cleaned or replace it.

7

Run a compression check whether the misfire continues. Use a compression tester specifically for car motors. Poor compression indicates a leak in the cylinder and will most likely mandate a check of the valve train or an engine rebuild.

You can adjust the rear drum brakes on your Saturn right from your home garage, saving yourself time and money. You should adjust the rear brakes periodically to keep them in the best working condition. As you use your brakes, they wear down a bit causing a space between the shoes and the drum. To close up this space, you need to do an adjustment with a few basic tools you can purchase from your local auto parts retailer.

Instructions

1

Disengage the parking brake. Place a wheel chock behind each of the Saturns front wheels to keep the vehicle from accidentally moving while you work.

2

Lift up the rear of the car with a floor jack, high enough to slide the jack stands underneath the car next to each control arm by the wheels. Slide the jack stands into place and lower the car onto them.

3

Put on a respirator mask, which you can purchase from any hardware store, to protect yourself from brake pad dust. Remove the lug nuts with a lug wrench. Take off the wheel and set it aside with the lug nuts.

4

Twist off the drums clockwise. If they are stuck, strike them with a hammer gently and twist again.

5

Locate the star-shaped self-adjuster under the wheel cylinder. Spread the shoes open a bit by turning the self-adjuster. Slip the drums back onto the shoes. They should slide on easily if you did the adjustment correctly.

6

Put the wheels back on the Saturn and tighten the lug nuts. Lift up the car with the jack and slide the jack stands out. Lower the car to the ground. Lift up on the parking brake, which should only move up six notches maximum.

7

Tighten the lug nuts all the way with the lug wrench and remove the wheel chocks.

You can read your Saturns service light using an OBDII reader right from your own garage, saving yourself time and money. The Saturn has an On-Board Diagnostics (OBD) computer that notifies the driver of problems with the vehicle. It also alerts you to when you need to perform regular routine maintenance and service on your car. To find out exactly what type of servicing your Saturn needs, you can read the computer codes using an OBDII reader. These readers come with a booklet that translates the numerical codes, although some readers display the codes description on the devices screen.

Instructions

1

Put the key into the ignition and turn it to the "On" position. Do not start the engine.

2

Locate an open port under the steering column near the fuse panel. Make sure its the same size and shape as the connective end on your OBDII reader. Plug the OBDII reader into this port. The Saturns electrical system will automatically power most OBDII readers.

3

Wait for the device to read the codes. Look up the service codes in the booklet, if the description isnt displayed automatically on the readers display. Write down the code and description on a piece of paper.

4

Unplug the reader and turn off the vehicle. Take your vehicle, and the code and description to your mechanic to have the vehicle serviced.