Alright this 87' XJ is somewhat my first vehicle since I traded my 76' F100 for it because I wanted to get into wheeling/mudding. So the other day my brother, my friend, and I took my XJ and my brothers Bronco II out for some very light mudding it ended up just stoping. It stopped after some fast puddle hopping and rut riding when I realized my temp hit about 220 degrees and it apparently stalls out my Jeep at a certain. So to get it out of the valley are my brother's B2 pushes me up to the trail entrance and let it cool down, once it cooled off enough to started I blasted up to the top of the entrance where it stalled again and had to be pushed down the hill to get it back to our house. As of saturday I started thinking what could of caused it and one of the things I thought of was the thermostat. I open up the housing and guess what I find! Nothing there was no thermostat there at all so I get a replacement one put it in. I think thats all good now but nope we start filling the coolant bottle back up and it decides to make one of the hoses bust. So after that wall of text besides some new hoses what else should I go about replacing while I going in the engine bay.

I would first familiarize yourself with the great wonders of the renix world. Any XJs produced from 87 to 90 have the renix fuel injection system, which comes along with many other unique things.

Read through some of these: https://www.cherokeeforum.com/f23/te...itings-136452/

Sorry posted before I saw that post
I have heard some fun things about us Renix era XJs, so what specifically should I be looking out for and get to know?

Well, on average they get a little less mpg than the newer ones.
-The old style engine has a little less power.
-Pre-89 models have the dreaded C-101 connector which basically relays everything from under the hood to the computer. Keep that clean and in working order, or get a new one and put it in.
-There is only 1 o2 sensor, and don't expect a check engine light to come on when it's time to change it. The renix system throws no codes and has no fancy lights on the gauges, aside from when fuel is low. Codes can only be read after at least 50 miles of constant driving, without shutting the engine off, and a special tool has to be used. That special tool also isn't around much anymore. There is no obd I or obd II port, there are two fancy connections by the coil that are used.
-The injectors can leak over time, which is a bad thing.
-The cooling system is temperamental, which you already got a taste of.
-There are a zillion vacuum lines, and one disconnected or broken can throw the whole engine out of whack in some cases.
-The idle is very low, usually around 350-750 rpm. It's perfectly normal.
-It takes about 5 seconds to start, which is also normal.
-The check valve in the fuel regulator can wear out over time, which will lead to a longer crank time before it starts. Just turn the key a few times, then crank it. That primes the fuel system and it'll be fine.
-there is no rev limiter, so be careful when revving it up to redline.
-the fuel injection system is the most reliable of the XJs, just a PITA to figure out when something goes wrong.
-we have the older style axle disconnect up front, which is quite nice.
-the older D35 is stronger than the newer one, has no c-clips, and is also a limited slip diff.
-forget about doing a cold air intake, there are very few aftermarket options and i'm not too fond of any of them.

The list can go on. With a renix, you can either love it or hate it. I happen to love it. It's a different breed of the XJ, and just as great as the young guns still trotting around. Mine has almost 237k and still runs strong. I'm hoping to reach over 300k with it.

Yea the cooling system ain't liking me to much and is pretty frustrating so far. I hope since I got some time before it really has duties as a DD I can look over some of that and clean it up before it comes up as a problem. Thankfully I got the XJ at only 99k miles and hope to take it for maybe another 100k, I feel like I am going to like the Jeep just gotta use to its quirks. When do some of these things start popping up normally? Also, what are popular engine swaps in Cherokees? I am curious because down the road I might wanna switch it up.

On the 87-90 XJs you have to carefully bleed all of the air out of the cooling system. They are prone to get air pockets in the cooling system and that will cause an overheating condition.

Any easy way to bleed all the air out?

Drill a small hole in the rim of the thermostat and put it in with hole in top position. The air then will bleed out by itself. The hole only have to be about 3mm.
Have to it to all the renix engines that I have and it works wonderful.

This. Works for none RENIX engines too.

Yes. and replace the coolant bottle cap with a different one from Napa. 703-1396.

You should refresh your grounds, check your sensor ground circuit, clean the c101, refresh all the connectors in the engine bay including the coil/ICU contacts. I have write-ups for all of these things and more. I will post them if you want me to. They cost nothing but a littel time and are easy to do. Helps you get familiar with your Jeep at the same time.

THIS. I replaced my coolant bottle and never had another cooling issue.

While replacing the bottle is good, the caps that come with them are crap. Even on a bottle that's not new, the Napa cap fits well.

I bought mine from o'reilly's I cant remember the brand, it was the same exact size, etc, but the cap was pretty beefy and the plastic on the bottle itself seemed to be much higher grade. It was like 29 bucks cap and all.

I have an 87 as well. I also had the cooling issues and decided to convert it to an open system. It was very easy and inexpensive; cost me around $50. At the same time I replaced my water pump, fan clutch, and belt. I did a full ground refreshing and spent a lot of time properly cleaning out the black tar from the C-101 connector. I cleaned all relay connectors and put brand new relays in them. Of course I used gobs of dielectric grease in all the electrical connections, including the C-101 connector. I changed out the plugs, wires, distributor, and distributor arm. I pulled all the fuses from the fuse block, cleaned them, cleaned the fuse receptacles, and re-installed (I did this when I found one fuse had so much crud that it wasn't completing the circuit). I swapped out my "idiot light" instrument cluster with a "gauge" cluster, and replaced the oil pressure and temp senders with the proper senders.

Bad grounds and sketchy connections wreak havoc with the Renix engines. I would highly recommend you do a complete ground refresh. Here's a great guide to ground refresh, https://www.cherokeeforum.com/f2/tak...6/#post1954065.

For searching, I recommend you use Google and just append all your search terms with "site:cherokeeforum.com" (without quotes), like this {search terms} site:cherokeeforum.com. Good luck!