Engine light is on the heater does not always throw warm air is it the thermostat and is it an easy fix?
Yes, it could be the thermostat, and yes it is pretty easy to fix. Here's how.
The location of the thermostat for most vehicle.
Stand in front of the car with the hood open, you'll see a black hose hooked to the upper side of the
radiator.( about 2 inch in diameter, newer vehicles about 1 and 1/2 inch, and newer small cars
about 1 and 1/4 inch. ) Follow the hose to the other end, it connects to the thermostat housing.
The thermostat is inside of the housing.( the hose usually goes to the air intake manifold, but some housings are on the side or back of the engine. )
How to test the thermostat in most vehicles;
Make sure the heater is off, start the engine and let it run for 6 to 8 minutes, ( this will allow the
engine to reach, " normal operating temperature "), from the inside of the vehicle turn the heater
temperature on high and turn the fan speed on high.
1. Listen very closely for a click sound from the engine, ( most thermostats make a click when
they open )
2. Watch your temperature guage, it should begin to lower as the coolant starts to circulate.
3. Usually within a few minutes the radiator fan will kick.
To replace the thermostat in most vehicles yourself;
Remove the hose from the housing, then remove bolts from the housing and lift the housing off
to access the thermostat. Pay attention to witch side is up on the thermostat that you remove, the
new one will have to go in the same way. Also look at the temperature rating that is stamped into
the thermostat that you take out, and make sure the new one has the same temperature rating.
(failure to do so can cause false readings by some sensors, and may start triggering error codes)
Install new thermostat, right side up, put housing back on and bolt back down, hook hose back on
to the housing. Check the coolant level. Start the engine and let it run for 6 to 8 minutes to reach,
"normal operating temperature", and look for any leaking. before you turn the engine off turn your
heater wide open and listen for a click. Most of the time when a thermostat opens you can hear a
click and may hear the coolant flowing through the system. Shut the engine off, wait for it to cool
down and then check your coolant level one more time. ( do not fill all the way up, only fill to
FULL line on resrvior.)
What the thermostat does;
It seperates your coolant into two parts. The first part is in your engine, the second part is in your
radiator and the coolant reservior. When the coolant in the engine reaches the temperature rating
on the thermostat the thermostat opens to allow the two parts of coolant to change places. Now
the cooled coolant in the radiator and reservior flows into the engine while the heated coolant flows
from the engine into the radiator and reservior to be air cooled by the radiator fan.
I hope this helps you.
Feb 02, 2011 |
1996 Mercury Grand Marquis