How to Replace a Bad Thermostat in Your Car

one, two, three, four!

Rev up your engines!

It's time for the Scotty Kilmer Channel

today I'm going to show you how to replace a bad thermostat on your vehicle,

now thermostats are pretty simple devices, when engines cold,

the spring keeps them closed, so hot water stays in the engine and warms up

faster, then once the engine heats up, the spring heats up, it opens the valve and

lets water go into the radiator to cool the engine, but like any other mechanical

part, they break eventually, they either break where they shut closed

and the engine overheats, or they stick open the engine runs to cool, and then

the check engine light comes on, in this case it's stuck open, then when I hook up

the scan tool, it says P 0128 coolant thermostat cooling temperature below

thermostat regulating temperature, so we're going to put a new thermostat in,

we'll follow the lower radiator hose that comes up to the engine here, and this is

the thermostat housing, it has big bolts on it you take off, in order to remove

the thermostat, but first we'll stick a pan under there to catch any drips of

the antifreeze that comes out when we take it off, we'll just get a wrench, this is a 12

millimeter, stick it on, take the bolts off, and to make the job easier,

I'll take the radiator hose off, you loosen the clamp, then just pull the hose

out of the way, that makes it easier to get the assembly out of the way, and

here it is, here's the thermostat, it's broken into two pieces, the other piece

we got to pull off the inside, so we know it was stuck wide open, now even though

the thermostat is simple, you can put it in backwards, the way you put it in is, the

short end goes towards the hose, and the deep end goes towards the engine, if you

put it in the other way, that's backwards, you want to make sure you have it in the

correct direction, and if you look closely this one, you see there's a

little toggle switch here, that's to let air go through the system, so you make

sure that the toggle switch is pointed straight up to the top of the engine, so

the air can get out faster, now on this Toyota, first you put the thermostat into

the housing on the engine, it has a rubber gasket inside, and then you put

the top of the cover on it and bolt it on, then you tighten all the bolts up nice

and tight, and slide the radiator hose back on,

and then use pliers and slide the clamp back on, then pour the coolant back in

the radiator, then start her up and turn the heat on full blast, while the engine is

warming up, you pour coolant in the radiator until it gets nice and warm and

all the air is out of the system, and then you're done, so the next time your

thermostat goes bad, why not replace it yourself,

and remember if you have any car questions just visit the Scotty Kilmer

channel and I'll answer them as soon as I'm done opening this coconut!