Temperature gauge

COLDAW

MEMBER
1995 TOYOTA COROLLA
1.8L
4 CYL
2WD
AUTOMATIC
160,000 MILES

Hi, I have owned the car for over ten years, the temperature gauge was always exactly half way, never budged. Now it only goes up part way, about 1/2" - 3/4" below the half way mark and the air is only lukewarm, not hot. When I turn the heater/defroster on, it goes down more. It never reaches the half way mark anymore. I am concerned with a long winter ahead that if it gets any worse I will not be able to drive without the ability to warm my windows to see. I really appreciate any advice you can give. I was thinking it could be the thermostat but all the information I read online, I could not find the exact same symptoms. Thanks so much.

3 Replies

JACOBANDNICKOLAS

MECHANIC
109,700 POSTS

Hi and thanks for using 2CarPros.com

You are exactly correct. Chances are the thermostat is stuck open, not allowing the engine to heat up enough. That will also result in lack of heat in the car.

Here is a link that shows how one is replaced in general:

https://www.2carpros.com/articles/replace-thermostat

Here are the directions specific to your vehicle. All attached pictures correlate with the directions. Please make sure to pay attention to the last picture. It indicates positioning what is called a jiggle valve. If you do not place it within the manufacture's recommend location, it will create a lot of trouble when refilling the cooling system.

_______________________________

REMOVAL
1. Drain engine coolant

2. Disconnect Engine Coolant Temperature (ECT) switch connector.
3. Remove water inlet and thermostat as follows:
a. Remove the 2 nuts and water inlet from the water inlet housing.
b. Remove the thermostat.
c. Remove the gasket from the thermostat.

INSTALLATION
1. Place thermostat in water inlet housing as follows:
a. Install a new gasket onto the thermostat.
b. Align the thermostat jiggle valve with the upper side of the stud bolt, and insert the thermostat in the water inlet housing.

NOTE: The jiggle valve may be set within 10° of either side of the prescribed position.

2. Install water inlet. Install the water inlet with the 2 nuts. Torque to 9.3 Nm (82 inch lbs.).
3. Connect ECT switch connector.
4. Fill radiator with engine coolant.
5. Start engine and check for leaks.

___________________

Let me know if this helps. Additionally, if you have other questions, let me know.

Take care,
Joe

Images (Click to make bigger)