Find solution

The thermostat on the 1988 Buick LeSabre is located partially inside the intake manifold and the thermostat housing. Because the thermostat sits higher than the fluid level in the radiator, replacing the thermostat in the LeSabre is an uncomplicated task. Fortunately, the thermostat housing is not hidden among engine accessories. This makes it easier to reach, remove and replace a broken thermostat.

Instructions

1

Follow the upper radiator hose to the point where the hose connects to the LeSabres engine. The metal connector to which the hose connects is the thermostat housing.

2

Disconnect the radiator hose from the housing by squeezing the pressure tabs on the radiator hose clamp together with a pair of pliers. With the pressure released, pull the hose off the housing. A small amount of fluid may run onto the engine block. To minimize this, hold the hose vertical for a few seconds to drain the fluid back into the radiator.

3

Remove the two bolts that secure the thermostat housing to the Buicks intake manifold with a 7/16-inch socket and ratchet. With the bolts removed, apply pressure on the side of the housing with the ball of your hand to break the seal between the housing and the intake.

4

Pull the old thermostat out of the intake manifold and plug the hole with a shop towel to prevent anything from getting into the coolant system of your Buick.

5

Scrape all the old gasket material off the bottom of the thermostat housing and the mating surface of the intake manifold. Brush off any debris with a shop towel.

6

Remove the shop towel from the intake manifold and place the new thermostat into the hole. The end with the large spring submerges into the intake manifold and the end with the pin sits inside the thermostat housing.

7

Place a thin bead of RTV gasket maker on the bottom edge of the thermostat gasket. Allow the RTV gasket maker to firm up for approximately 20 minutes. This creates a small layer of "skin" on the RTV.

8

Place the thermostat housing onto the intake manifold and bolt it into place. Do not wipe off any excess RTV. It serves as additional sealant.

9

Squeeze the pressure tabs on the radiator hose clamp. With pressure released, slide the hose onto the thermostat housing and then let go of the tabs.

Oxygen Detection

The oxygen sensor informs a car computer of the level of oxygen being burned into the fuel. The computer utilizes this information to regulate the mixture of fuel to oxygen. Installing the oxygen sensor in the exhaust manifold allows the amount of O2 in the fuel mixture to be measured. A zirconium ceramic bulb (enameled in a layer of platinum with oxygen holes) is attached to the end of the oxygen sensor (At the end where the sensor is bolted into the exhaust manifold). Two leads platinum electrodes reside inside of the bulb. A very small amount of space is provided for the insulation and the wire. Air must be allowed to reach the oxygen sensor. When installing the oxygen sensor, no grease is used (grease inhibits the flow of oxygen to the sensor).

Heating

At a hot enough temperature the oxygen sensor will produce enough voltage to communicate with the car computer. Typically, the oxygen sensor will include a heating device inside of it. This heating device aids the oxygen sensor by quickly raising the operating temperature (600+ degrees Fahrenheit). Thus a signal to the car computer is produced in a timely manner. Older cars typically have a single lead (wire directly connected to the oxygen sensor) on the oxygen sensor and lack a heating device (operating temperature takes longer to reach). New cars typically possess a self heating oxygen sensor with three or more leads (multiple wires which are directly connected to the oxygen sensor). Over the years, the number of oxygen sensors in any new car has doubled.

Modern Sensor Systems

Modern cars have a second oxygen sensor installed in or behind the catalytic converter. This oxygen sensor monitors converter production. Bigger engines require one oxygen sensor to be installed per cylinder, and an additional oxygen sensor following a catalytic converter. Upstream/ downstream oxygen sensors are installed in many of todays newer cars to monitor emissions performance. This oxygen sensor ensures the converter minimizes pollution (exhaust). Converter failure prompts the malfunction indicator lamp to light up on the dashboard.

Tooling and Wiring

A 22-millimeter socket is used to remove the oxygen sensor from a car. The engine needs to be warmed up just a little bit before removing the oxygen sensor, otherwise the sensor may not budge. The socket is turned counter-clockwise over the bolt holding the sensor in place. Penetrating oil may be used around the bottom of the sensor to help loosen it from its fixture. Wiring on the connector fits all OEM oxygen sensors. Universal oxygen sensors, however, require the wiring connector to be cut. The wires are spliced to connect the connectors wires. Modern sensors typically have four wires (signal, ground, and two wires for the heater circuit. Color coding on a new sensor will not match leads on older converters.

The design of a newer mirror assembly allows for a moderate amount of impact before breaking. The assembly has springs that allow it to flex both forwards and backwards. If the impact is hard enough, the plastic assembly could crack. If this happens, pulling the old mirror off and replacing it with a new side-view mirror assembly is necessary.

Instructions

1

Remove the cover located inside the door, opposite the rear-view mirror. The cover does not have screws. Instead, it has a few plastic tabs that press into slots in the door. To remove the cover, pull it off with your fingers.

2

Locate the wiring harness behind the cover. Disconnect the mirror motor from the vehicle by lifting up on the locking tab in the center of the connector. With the lock lifted, pull the two ends of the connector apart.

3

Roll the window down so you can hold the mirror and remove the nuts that secure the mirror to the door at the same time.

4

Remove all but one of the nuts that secure the mirror to the door. The nuts are located behind the cover you removed. Usually, there are three nuts. Use a long-well socket and ratchet.

5

Hold the mirror against the door and remove the final nut. Do not let the mirror fall out of the door. You risk scratching the paint on the door with the threaded posts used to hold the mirror in place.

6

Pull the mirror out of the door. Again, be caul not to scratch the door.

7

Slide the new mirror on the door.

8

Hold the mirror and thread all of the nuts onto the threaded post with your fingers.

9

Tighten each bolt with the long-well socket and ratchet.

10

Reconnect the electrical harness by sliding the two connectors together and pushing the locking tab back into place.

11

Snap the cover back onto the inside of the door by pressing it in place with your hand