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better t-stat?

in4aride

in4aride

NAXJA Forum User
Location
Montrose
is there any thermostats better than others?

jeep has a 180* in, and it doesnt get warm enough, so i was gonna toss a higher one in, but didnt know if there was any difference or if napa stuff was good enough? :dunno:
 
With it having a 180* t-stat in it already, I'd be more concerned with if it's stuck open and not allowing the engine block to build heat.

Secondly, see if you can get a liquid thermometer and test the actual temp of the coolant at operating temp and double check that it's not reaching 180*.

I wouldn't want a higher temp t-stat in an XJ with a 4.0.......
 
YELLAHEEP said:
With it having a 180* t-stat in it already, I'd be more concerned with if it's stuck open and not allowing the engine block to build heat.

Secondly, see if you can get a liquid thermometer and test the actual temp of the coolant at operating temp and double check that it's not reaching 180*.

I wouldn't want a higher temp t-stat in an XJ with a 4.0.......
Click to expand...
ya, it doesnt seem to build heat at all, gets to about 160* or so and stays there, so heat is only mildly warm, not so bueno.

aux fan has yet to come on since ive owned it...
 
Sounds like a good flowing radiator with an open t-stat, or one that opens way too soon. Remove the t-stat, if it's closed, put it in a pot of water and bring to temp with a thermometer and see if it opens when it should.

I don't think putting in a higher temp t-stat is wise just yet. Could regret it this summer.
 
ok, i had considered putting a 180 back in this summer when i change coolant? :dunno:

if its open when i pull out just replace with a 180 again?
 
in4aride said:
ok, i had considered putting a 180 back in this summer when i change coolant? :dunno:
Click to expand...

Why do extra work?

in4aride said:
if its open when i pull out just replace with a 180 again?
Click to expand...

Yep.


Ya know....... your rig is a '90 right? Is your concern with temp because the heater isn't getting warm enough? Or is the temp gauge reading low too?

The heater control valve could also be malfunctioning. The vacuum actuator may not be opening the valve enough to let good hot water into the heater core.......

You can check 'em by hand. Move the lever that the vac. actuator is attached to and see that it moves easy and seems to open/close ok. Then with the jeep running, look at the position of the lever to ensure the actuator is pulling it open enough. If not, test the actuator to see if it's holding vacuum.

Which would again, be a good reason to get an actual temp reading of the coolant at the radiator/overflow bottle with a liquid thermometer and ensure that the block isn't actually at good operating temp.

But my money is still on an open t-stat.
 
temp guage reads low, like i said i think the hottest ive seen it is 160* or so,
you can feel the change in temp and where air comes from, just seems as tho the heat isnt as hot, and i was correlating it to the tstat
 
In my experience, lack of heat is not normally a t-stat failure/problem. You could have an air pocket in the system. I can grab my AirLift from work and we can get all the air outta there in less than 5 minutes, if you want.

I've got a 180 in the 2door and the gauge never reads past 160-170. Actual coolant temp is around 195-205*, though. Factory gauges are a crap.
 
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ClarkPeach said:
In my experience, lack of heat is not normally a t-stat failure/problem. You could have an air pocket in the system. I can grab my AirLift from work and we can get all the air outta there in less than 5 minutes, if you want.

I've got a 180 in the 2door and the gauge never reads past 160-170. Actual coolant temp is around 195-205*, though. Factory gauges are a crap.
Click to expand...

Nah, air pockets cause the coolant to not flow between the block and the radiator........ and the result is overheating. Every Renix engine I've had or had experience with during trail runs when someone has overheated, it's been remedied by removing the temp sender at the back of the head and "burp" the air out. Then things return to normal.

Air pockets never result in cool engines.

But yeah, factory temp gauges and sensors....... not very reliable at all.
 
i understand they arent reliable, BUT
the combination of low temps on guage and low temps from heat should make it relatively reliable that something is up and needs fixed and im guessing tstat would be best start?
 
Yeah Mike, you're right on track. Just pull the t-stat and check if it's open or not, then heat it up and see if it's opening at all. If it's open when you pull it, it's stuck as it should close when the engine is cool.

If your replacement t-stat doesn't have a bleeder hole in it, do yourself a HUGE favor and take a small drill bit and put one in it - it'll save alot of issues with bleeding air and moving coolant into the block. Best way to fill the radiator and a Renix engine block is to remove the upper radiator hose, and fill through the t-stat housing. If at all possible, have the XJ pointed nose-up a bit so water settles to the back of the block first.

Pic of bleed hole and position it should be in when installed:

images


When I install 'em, this is the same size and location I drill the hole:

images
 
Isn't the stock t stat a 195? Been so long since I had to mess with it I don't remember. My white Jeep runs on the cool side during the cold months and it does make the heater suck.
 
Frank Z said:
Seriously.

Drop a 190 T-stat in some boiling water. When it opens, insert an asprin to keep it open. Install the t-stat and fill with coolant. Tthe coolant will desolve the asprin but not before all of the air is purged from the engine block.
Click to expand...

Clever, but that only works for the initial install. If you blow a hose or radiator later on and need to add a bunch of coolant or are doing a flush, the drilled hole will save headaches in the future...... your aspirin is only a first headache cure....... :D
 
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