Help! Where is the water coolant temp sensor?
Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country
Any time I mess with the cooling system:
Open cap, fill reservoir
start engine, turn on heat and let idle until thermostat opens
keep reservoir full as coolant flows into system and squeeze rad hoses to pump coolant through
when coolant level stabilizes put cap on and let build a little pressure
open cap and see if level changes, if not, drive it around for 10 minutes
let it cool down and remove cap and check level
sometimes I repeat the process if it seems necessary, usually this works the first time.
when possible, I do not drain the whole system, only pop off the upper radiator hose. it's a little messier but keeps the bottom half of the system full. much easier when you fill it back up.
Open cap, fill reservoir
start engine, turn on heat and let idle until thermostat opens
keep reservoir full as coolant flows into system and squeeze rad hoses to pump coolant through
when coolant level stabilizes put cap on and let build a little pressure
open cap and see if level changes, if not, drive it around for 10 minutes
let it cool down and remove cap and check level
sometimes I repeat the process if it seems necessary, usually this works the first time.
when possible, I do not drain the whole system, only pop off the upper radiator hose. it's a little messier but keeps the bottom half of the system full. much easier when you fill it back up.
Melting Slicks
Joined: Sep 2005
Posts: 2,670
Likes: 134
From: merritt island fl
C1 of Year Finalist (stock) 2019
2016 C1 of the Year Finalist
2015 C2 of the Year Finalist
It doesn't flow through all the time, it is valved and only flows when heat is asked for. However, when coolant is removed (like when you swap a thermostat) it's possible to get air in the heater core. You ask for heat to get the coolant to flow and move the air pocket out of the heater core.
Safety Car
Joined: May 2000
Posts: 4,827
Likes: 352
From: Albuquerque NM
Used to be, it was a valve controlled by a cable, when you moved the heat lever it opened the valve, located somewhere in the engine compartment, on the hose going to the heater core. With our electronic controls, I believe it's in the heater core area under the dash.
Melting Slicks
Joined: Sep 2005
Posts: 2,670
Likes: 134
From: merritt island fl
C1 of Year Finalist (stock) 2019
2016 C1 of the Year Finalist
2015 C2 of the Year Finalist
C-5s and C-6s don't have one. I don't think the C-7 does either.
Coolant ALWAYS flows through the heater core.
Safety Car
Joined: May 2000
Posts: 4,827
Likes: 352
From: Albuquerque NM
It's good to learn something new every now and again.
