Erik Hoeffner

I was just looking for help on locating and replacing the thermostat on my 91 XJ, an easy thorough quick guide if you can. Please and thank you.

ZINGGG

It's located at the very front of the block in the thermostat housing (also known as the water outlet). The housing will have 2 hoses and a temp sensor hooked up to it. If you drain the coolant, take out the hoses and sensor, you can unbolt the housing to access the thermostat. You also want to replace that gasket while you're in there.

If you pick up a repair manual, you'll get a more detailed explanation. And it'll be beneficial in the long run for other small jobs.

Jarrett

like said above it's at the very front...2 bolts holding on the housing cover. the bottom bolt is somewhat tricky because of the belt being in the way. The gasket you'll need to pick up is like $5. the t stat pops right out after the cover is off.

Carl48

Good advice.

Also, make sure you install the new thermostat in the right direction...spring end towards engine and air bleed (if there is one) up. Scrape off all the old gasket and install a new one.
Use a 195F thermostat. Buy a good quality...not offshore cheapo or you wiil be doing the job again. Torque specs for the bolts is 15 ft-lb...don't overtighten.

BobIsAwesome

And make sure the thermostat is seated in it's little recessed area before you start tightening down the housing. You will crack the housing if the thermostat slips out of it's recess.

Want an easy way to keep the thermostat in place as you work? Apply a very tiny bit of RTV around the edge of the thermostat, just a tiny thin ring all around the edge. stick the t-stat in it's place, wait a few minutes to dry, and tighten down the housing.

Also, the paper style gaskets were a pain in the butt for me, I just used water pump RTV all around. Worked like a charm and no leaks after, jeez, a couple months. http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Water-Pump-And-Thermostat-RTV-Silicone-Gasket-Permatex_7160009-P_N3284_T|GRP2053_____ This is the stuff.

Erik Hoeffner

Alright thanks for the help guys. I actually had to use other resources, as this site was down when I tried it earlier.
I actually didn't even drain the radiator, just put a bucket under the block for what spilled out out the head and hoses. Came to find I had a 180 degree in there for some reason.
Got it all done and I have heat in my car now after quite sometime...Hope to see my MPGs go up as well since the temp never got past 100.
Anyone know how much that may have affected my MPGs?
And is "Murray plus" a decent brand? thats what I picked up...

ZINGGG

You probably won't see a huge change in mpgs to be completely honest. I bought an xj and drove it around for 2 months before I realized the past owner wasn't even running a thermostat. After putting one in, there was virtually no change. But every rig is different. And you may see a slight increase