Questions and Answers

Nissan Stanza Thermostat Replacement Q. I have the following: 1990 Nissan Stanza 2.4 liter KA24E 4 cylinder engine 5-speed manual transmission 130,000 miles Fuel Injection

The engine runs cold, summer and winter, I live in NH, and it gets poor gas mileage, low to mid 20's. Also, I have to put cardboard in front of the radiator to get any heat. I want to improve the gas mileage by replacing the thermostat with a hotter one or one that works.

My key question is, where is the thermostat? I followed the top radiator hose back to the engine and it doesn't look like there is a place for a thermostat.

Any help on this would be appreciated.

A. Well, you were on the right track. It is mounted on the side of the water pump. I would recommend not using a thermostat higher than 180°.

After you replace the thermostat you will need to bleed the cooling system. Here's how to do it.

Clip the end off a paper clip so you have a "U" shaped wire. Then slide it under the negative pressure relief valve of the radiator cap.

Now fill the cooling system to the top of the filler neck and place the radiator cap on tightly. Fill the coolant reserve bottle about ¾ full. Start the engine and turn the heater to full HOT.

Now just let it run and soon you will see air bubbles coming up through the coolant reserve bottle. When the engine gets to normal operating temperature shut it off. Keep an eye on the coolant in the bottle and add some to keep the level up, do not let it go dry.

That will get most of the air out of the system. You may need to repeat the procedure once or twice.

There is also an air relief screw you need to open while filling the system. Keep adding coolant until it just starts to come out and then close it. Fill to the top of the radiator neck and continue with the above procedure.