I have a stock 97 cherokee, just noticed today that I drove it up the road about 5 mins away and it was already up past 220 and the electric fan was on, shut it off and listened and heard what sounded like the water boiling in the radiator, top hose was hot and had pressure but the heat wasn't working good either so could this be a thermostat stuck closed? It also didn't seem like the hoses running to the heater core was as hot as it should be, any help is appreciated

 

I would start by replacing the thermostat. Easy and cheap, costs about 10$ with gasket. Make sure you completely scrape the old gasket off well before you put the new one on or coolant will leak. Also replace when the engine is cold; Coolant will leak out, so have extra on hand as well.

 

Therw are tons threads on here that cover where to start. Trying searching for an answer first. That bring said, check your fluid level first. Try flushing the system until the water comes out clear. Put a OEM thermostat in it with the jiggle valve pointed up at 12 o'clock

 

Poor old t-stat always seems to get blamed 1st. It's the only cooling system component that can easily be tested (for free) on top the stove, in a pan of water, using a cooking thermometer. Another test that can be done (for free) is, run it without a stat......if it doesn't overheat, stat could be the culprit.....if it continues to overheat without a stat, the problem is elsewhere.

 

When is the last time the cooling system was serviced?

 

I'm not sure, only had it for a little over a year, but just started this today... Never had any issue at all before hand

 

Start your free testing......real easy to identify/eliminate the poor old t-stat as the culprit, or not. I'd almost bet money the t-stat is NOT the problem. Winter is just around the corner.....sounds like it is past time for some routine cooling system maintenance.....otherwise, the XJ cooling system can quickly bite u in the butt. Don't take the cooling system lightly.....routine preventative maintenance is a must. It's impossible to throw too much money/time at the XJ cooling system.

 

Both of the 2 above answers are the best way to answer your question.
Since you have no idea when the cooling system was last serviced this is the perfect time to take care of it. You can replace all of the cooling system components for $200-$250 and that will include a new water pump and radiator, from any Auto Zone or Advanced Auto. If you decide to go this route? Which I would highly recommend. Do Not forget to replace the commonly overlooked fan clutch. Also make sure to back flush the engine block and heater core separately from each other. After you replace all of the cooling system parts you should be good to go for many years to come. As long as you do the normal routine maintenance. Hope this helps. Let use know what you decide.

 

Thanks everybody but it was the thermostat stuck closed, put in a new one and is running steady 200-210

 

lol