Jeep running cold

[calvinh]

So I've got an interesting problem... My wrangler never gets above 150 degrees, or 1/4 the way up the temp gauge. I'm guessing this might be the thermostat going bad? I don't have a garage, so I'll be doing all the work in the parking lot in front of my building. Does the coolant need to be drained to replace the thermostat? or can I just take off the housing without draining the coolant?

Thanks!

[sharpxmen]

So I've got an interesting problem... My wrangler never gets above 150 degrees, or 1/4 the way up the temp gauge. I'm guessing this might be the thermostat going bad? I don't have a garage, so I'll be doing all the work in the parking lot in front of my building. Does the coolant need to be drained to replace the thermostat? or can I just take off the housing without draining the coolant?

Thanks!

you don't need to take all the coolant out just some until the level is below the cyl head, would be hard to tell how much but you could guestimate. if you don't drain any of it whatever is in the cyl head will come out when you take the thermostat housing off.

your guess is right, probably a stuck/bad thermostat is the cause or if for some reason you have a 160 deg one (i doubt it but you never know)

[jfrabat]

you don't need to take all the coolant out just some until the level is below the cyl head, would be hard to tell how much but you could guestimate. if you don't drain any of it whatever is in the cyl head will come out when you take the thermostat housing off.

your guess is right, probably a stuck/bad thermostat is the cause or if for some reason you have a 160 deg one (i doubt it but you never know)

Just take out a gallon or so... should be enough.  I have also had thermostats stuck in both the open and closed positions, and when they were stuck open, they had the same effect, so that's probably a good place to start...