I have an '87 XJ with a 4.0 only about 150,000 miles
Son was driving it home, noticed steam coming from the hood, then the engine died. We added a 2 liter bottle of water to the reservoir, engine started, and it sucked it right in. Tried to add more, but it won't pull in any more. The hoses feel empty, and the engine was very hot, but no water in the oil. No other signs of leaking coolant, appears to have blown out the overflow reservoir and all over that area.
Dragged it home and ready to go to bed!

One other important fact. We pulled the upper rad hose from the thermostat housing to try and add more water to the empty hose and into the radiator. Initially could see fluid in the thermostat housing sitting there, was very hot. After a couple seconds, the fluid started to slowly come out of the housing and spill.

Does this sound like a simple thermostat issue, or should I be looking at the water pump too?

Thanks for any advice!!

 

I would change the thermostat making sure to use a 195*.

Get a new cap for the reservoir at Napa 703-1396.

 

Replaced the thermostat, and since the water pump was only $20, did that too. Old pump looked fine, so it probably was the t stat.

 

I'd suggest getting that cap also I had the same problem in my Cherokee and had replaced everything except the radiator, that the hoses, thermo housing, t-stat, revisor, fan clutch, fan shroud, water pump, and even did my own 60/40 mix of water/coolant. Still was overheating enough that I wasn't comfortable with it, finally I took cruisers advice and got that Volvo cap #703-1396 haven't had a problem since.