After my wife complained that her car 1996 Saturn SL2 had the ‘High Engine Coolant Temperature’ light came on, I thought we should take care of that problem soon, but did not take any action. While I was driving the same car couple of days later, the same thing happened to me, and I drove the car straight to home and parked the car in the garage. Don’t want any engine melt-down.
Actually several years ago, we thought there might be a problem with the thermostat, and I had ordered a brand new thermostat, but never had it installed. The problem was that the temperature gauge was never moving. At the time I had replaced the temperature sensor to fix the problem, but the problem was never fixed.
When I looked under the car, I could see the green liquid dripping onto the garage floor. Just several days ago I had topped off the engine coolant reservoir, and I noticed that the level was low again. Probably the radiator was leaking.
I googled the problem and decided to attempt repairing the car. Bought a salvaged radiator from an auto wreckage parts store for $50.
The first step is to drain the coolant from the radiator.
The next step is to take the air intake box out. Two of the bolts are close to the battery and easy to take out. The last one is harder to find, it is on the other side of the air intake box.
The resonator has one of those one-time-use plastic rivets holding it down. Cut it down to release the resonator.
Underneath the car, there are four plastic rivets you need to take out to release the air dam/lower splash. It is a pain to deal with the plastic rivets, but they have to come out.
Remove the upper hose that connects to the engine. If your car is automatic, there will be two more hoses connecting to the radiator from the transmission. Ours is manual, so I didn’t have to deal with them.
Remove the lower hose on the left hand side as you are looking into the engine. You will see the thermostat housing on the engine side of the hose attached to the engine block.
The picture above shows also the plastic rivets.
Remove the oxygen sensor, and any other wires that are connected to the fan. As you are looking at the fan, there are two plastic rails on the left hand side. There is only one bolt on the right hand side. After you take the bolt out, and unhinge the left hand side of the fan, it will become loose. But, it is not so easy to remove it. You will have to move it just right for it to come out. There isn’t much clearance on either side.
There are two bolts holding the radiator to the frame. When you take them out, the radiator and the condenser that is attached to it will be loose. To release the radiator from the condenser there are two other bolts to take out. But be careful. When I did that, I said ‘oh sh*t’. You might say ‘oh darn’ or ‘jezus’, or some such thing. That is because there is absolutely nothing (but two hose connections on one side) holding it, and it will dangle maybe all the way to the garage floor. At that point there are only two hands, and both will be very busy.
After the radiator is out, the front of the engine compartment looked like this.
Old Radiator Out
To replace the thermostat, take out the two bolts attaching the thermostat housing to the engine block. In the picture below you can see the old thermostat in its housing, the new thermostat and the rubber gasket.
In order to take the old thermostat out of its housing, you will need to push on the spring and while pushing rotate it. Easier said than done. They sell a special tool to accomplish this, but I used a one inch water pipe as seen in the picture below.
After replacing the thermostat, bolt the housing onto the engine block.
Follow the steps in the reverse order to put everything back. But before you can do that you will need to make a trip to the local auto store to buy new plastic rivets and two gallons of coolant. I bought one gallon and had to make another trip.
When I drove the car around the block, I noticed that the temperature gauge started to work, and the coolant warning light did not come on. The car is still driving great, and the wife is happy.