If a cooling fan will not turn on as the temperature reaches 200 degrees F, the fan motor may need to be replaced. To remove the fan on a 1995 Cadillac STS, start by removing the front plastic guard. Many other cars cooling fans are almost identicle to this set up and can be repaired in the same way. The plastic “trees” that hold the guard on will often break, so beware.
Cooling fans are easy to troubleshoot. Some automobiles use two smaller fans or one larger fan. The twin electric fan set up will use one fan for cooling the engine. The other fan will be used for cooling the air conditioning and radiator but only works with the ac on. Never continue to run the vehicle up in the red temp zone or you can cause severe damage to the engine. First do you have a temperature gauge in the dash? Is it working correctly? Lift the hood and verify visually that the fan is not working. Does the car cool down once you drive up the highway at 40+ mph? If not, you may have a thermostat sticking or low coolant. The thermostat can cause the engine to stay hot. This can also be the problem if the gauge stays low and the car never heats up. If the temp gauge is reading low yet the two radiator hoses are warm, the temp sensor may not be working. There may also be two temp sensors or senders, one that controls the gauge and one to switch the fan on. If the temperature is getting high and the fan still won’t come on you may have a fan problem.
A car’s engine can surge for many reasons. Generally the ignition, wires, spark plugs, or the distributor rotor and cap will cause this problem. Another possibility is that your fuel filter is clogged. Injectors could also possibly be clogged on a high mileage vehicle. This is where a tune up can help your car. A vacuum leak can also cause surging problems. First inspect all hoses and fittings then around the carb or throttle body. Run the engine and spray carb cleaner on areas that could be leaking, the engine will die or speed up when you spray if there is a leak. A vacuum leak may or may not make your check engine light come on. Surging could come from a sensor problem or a leak causing the sensor to not operate correctly. It is always good to check your computer codes first if the light is on. This will help you to identify the problem area.
A compression test is a way of testing an engine’s condition without tearing the engine apart. A compression tester or tool is used to check the compression pressure. An engine compression test will let you know if there is excessive wear between the cylinder and piston. When the seal between the cylinder and piston rings wear out the engine’s compression will drop. This sealing failure will also cause the vehicle to use excessive oil and the car may start to smoke out of the exhaust. A four stroke engine, usually found in cars, will vary per car but should be around 170-200+ psi depending on the static compression ratio of the vehicle. With high performance cars having higher psi numbers with the exception of turbocharged cars having low psi numbers. Two stroke engines and small garden type engines will have considerably lower compression. Generally these engines will be around 80-140 psi. These are the steps to check your engine’s compression.
The ignition switch lock is not hard to replace. The switch first needs to be exposed by removing the colomn area covering it. Older cars use a clip or a pin that can be pressed, that will allow the switch module to slide out. Many newer cars use a clip and a pin to slide the switch out. Many times you will need to rotate the key to a certain position for the switch to slide out. The older switches use mechanical connections to transfer the voltage from the battery to the starter and the ignition coil. Newer ignition switches use a electronic switch called a proximity sensor. The prox. sensor sees an internal metal tab and will switch the 12 volts on. The switch allows the car engine to spin over, start, then stay running.
A water pump circulates water from the engine and through the radiator to keep the engine cool. Most cars need a water pump somewhere around 120,000+ miles. Some cars like Hondas have the pump by the timing belt and some are driven off of it. These type of cars should replace the water pump at the same time the timing belt is replaced. The water pump is easy to replace in comparison to the timing belt. If not replaced, the water pump tends to die soon after replacement of the new, tighter timing belt. Many newer front wheel drive cars have the water pump on the left side of the engine. The pump is driven off an accessory belt that will need to be removed first. The belt tensioner will first have to be loosened. Many times the alternator acts as the tensioning device.
