I have to replace the coolant temp sensor on my 2.5L engine. I may be an idiot for asking, but do I have to bleed the cooling system after I take out this old sensor, or can I just plug in the new one with no adverse affects (assuming that the sensor was the only problem)?
Thanks,
Joe
There was no mention of what model you have your 2.5 in. On the Spirit/Acclaim, the radiator sits lower than the thermostat housing, so it is a good idea to bleed the system anytime it is opened, other than the radiator cap. There is a bleeder plug on the thermostat housing for this purpose.
-Kirk Matheson
with kma on this one, bleed the system after replace. The therm. housing traps air and has to be bled anytime the system is de-pressurized, sigh.
I have a 1988 Aries.....
I guess I'll have to wait to get home to do the procedure.
Thanks,
Joe
If ya have a bleed plug on the therm. housing, you'll see it. It a simple deal, run the engine to ooperating temp., loosen the bleed valve to let the air escape until only coolant runs out of it.
1] Try to open the valve before any engine run, make sure it hasn't frozen up. 2] Be careful not to open it up too much, too much coolant may spray onto the serpentine belt, not a good thing. Also, ya may get some steam coming out, so watch your hands. 3] Keep eye on coolant level in reservoir tank.Hope this helps. I surfed autozone's site for your model, no listing of a bleeder valve in the therm. housing, but if it there, it easy to spot.
Now, looking at the thermostat housing, there are two allen wrench fittings: one on top of the housing, and one on the side near the coolant sensor. Which one of these would I use to bleed the system once I get the new sensor in?
I've never done anything like this, so forgive me for sounding dumb...but do I replace the sensor with the engine cold, and leave the new one loose, and THEN start up the engine and allow it to warm up? Won't there be antifreeze everywhere?
yes
It depends. If your antifreeze is properly mixed then it takes a lot of heat for it to start boiling in an unpressurized system. By then the major air bubbles will have worked their way to the bleed hole and you will have poured in more antifreeze into the sensor hole to displace the air, and screwed in the sensor. It takes time for heat to work it's way into the coolant from the cylinder walls.
Once the water jacket gets hot enough for the antifreeze to boil in an unprsssurized system, then when that happens, yes a lot of antifreeze will want to come out of the hole.
You should have at least 5 minutes of time before this starts happening.
Ted
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