jeepxj99

Okay, so my XJ is a 99 4.0, with stock everything. Due to my job being farther away, I no longer drive the thing on a daily basis. Sadly, it sat for a couple of months and wouldn't crank, no power. So I yanked the battery and sure enough, dead cell. Replaced the battery and it cranked right up. So I decided to go for a ride. Everything seemed normal (good oil pressure, temp normal) until after about 15 miles. I began smelling a burning smell. I don't know really how to describe it, just burning. I noticed the temp gauge had crept up to about 235 or so, but was holding steady at that temp. I pulled over and got out, noticing the smell and very faint smoke blowing from underneath. The smell and smoke quickly subsided and I let it cool down for a few minutes before I turned around to head back home. On the way home, I began to get a slight vibration in the wheel, which turned into a violent shake of the vehicle. When I slowed down, it too subsided. The temperature had been holding steady below 210 until this point and slowly crept back up to 235 or so. When I got home, the burning smell had returned.

The next day I idled it for half hour and it held normal temp (below 210) for almost the entire half hour before slowing climbing back to 235. However, no burning smell and no smoke.

Things I've checked:
Coolant is neon green in Radiator - overflow tank had slight sludgy

Oil was correct color and level, not milky or light

Started with radiator cap off and no bubbling or spilling over

Trans. fluid is a little brown, but doesn't smell burnt. It's old.

The t stat, water pump, and temp sensor all replaced in last 12 months.

I'm almost wondering if I have two separate issues here. One with cooling system and the other with the burning smell, smoke, and shaking.

NewbJeep

You have a few issues, IMO. I'll see if I can help out. There are well-more experienced members here but I'm going to take a crack at your problems since I have experienced some of the same.

The color of the antifreeze is not an indication of health. Changing yearly is good practice.
Did your heat creep up at idle or highway speeds? (idle = fans, hwy speeds = poor flow, typically). How's your belt? Is the burning smell rubber, exhaust or antifreeze? Your belt might be seizing on something (ie: rusty a/c clutch from sitting) causing a poor circulation on the water pump.

Your car sat, which machines don't like to do. It sounds like your shake is a death wobble and since it sat, you may have a flat spot or some kind of failure in the tire. How did the tires look? Did they go flat in that couple of months? Crawl under and check on the front end parts. Death Wobble is hard to diagnose but start with checking your track bar and then go here.

It's not causing your problems but since you mentioned it, drain and fill your trans fluid at least once. There's a drain plug so it's easy and cheap. Dex/Merc fluid. If you're not on a budget, drain and fill a couple times over the course of a week. It only drains 3.8 qts and the full capacity of trans and torque converter is ~12 qts. So you'll be mixing old with new but don't worry about it. Or if you want all new fluid, do this. Don't do the pressure flush or whatever Crappy Lube tries to sell you.

Good luck and keep everyone updated so the next guy searching for the same problems knows what to do.

jeepxj99

Thanks for the response, NewbJeep. A couple of things to clarify:

1. anti-freeze was replaced with the t stat and sensor about 6 months ago.

2. The heat creep originally occurred while driving. But, the temperature was normal for about 15 hwy miles at 55 mph. I did get the temperature to creep to the same point while at idle, but it held steady below 210 for half an hour before the creep.

3. Main fan and Aux fan appear to work.

4. The burning smell honestly doesn't smell like burning rubber and the belt looked fine.

5. The tires looked okay. They were a little low on air, but I filled them back up to level before driving it.

The only other thing I can think of is that before I stopped driving it, there was a slight popping noise when turning the front wheels that sounded like it was coming from the driver side front area. Any idea what that is?

NewbJeep

Lot's of things go pop under the front end when they break. Have to get under there and look. Noggin' pokin', as it's called. Bring a flashlight.

There's not a really fool-proof way to test a fan clutch but with the engine at operating temp, shut it down and spin the fan by hand. It should not move freely. It sounds like you have a clogged radiator or bad water pump if it's overheating at highway speeds. Water pumps, depending on the brand, can go bad inside of a year. Same with the thermostat. I don't know how to test this so you'll have to wait for a more experienced member to chime in.