is the resv. suppose to swell a little at all time while running? it runs at 210 and sometimes goes a little above for a few then back to 210. just notice it swells up some after jeep warms up.

 

Sounds pretty normal, I had an 87 XJ and the bottle seemed to swell, but just slightly.

 

Both of my XJs puke tanks doo that but make sure your temp guage is acurate i helped c-loss put new electronic temp guage in his 88 with a new thermostat housing for the high output 4.0 to find out his factory temp guage was wrong.

 

A little swelling is normal.. But check it for cracks. This is how they fail often.

210 degrees on a Renix Cherokee is the normal operating temp. The electric cooling fan is set to come on at 210 degrees.