hydraulic fluid (PS fluid) + hot surface (like exhaust manifold) = fire

Hydraulic fluid is really flammable

 

I checked the fluids and none of them seem low, as far as I could tell with the Jeep off. I get lots of smoke immediately when I start it, so I can't check the tranny fluid properly... but I took a picture of where it was smoking, and it seems to be originating from behind the engine, somewhere down below and behind it. The odor is real foul, like I said earlier and maybe even to include burnt plastic. There was no visible fluid spray when my wife turned the wheel for me. She turned it left then right then straightened it out and she said it was very easy to turn. She said she heard a slow click in the steering wheel, relative to the motion of her turning it - when she turned it to the left, but not when she turned it to the right. I could not hear the click from the front of the engine, but I didn't want to leave it on any longer because of the smoke.

So, no spray, still smoke, but from behind and under. Could not see where from when I peeked from under driver-side, behind front driver-side wheel, and the wheels did respond to her steering motion.

 

So you are thinking its trans fluid?

 

when was the last time you changed the fluid in your front differential? is it possible that someone may have put trans fluid in there?
i'm wondering if maybe 4 low didn't disengage, and when you hit freeway speeds, you had some fluid (whatever was in there) blow out the vent tube. (my vent tube sits right in that area where you noted the smoke)....just a thought.

 

I would assume you are getting smoke because of all the fluid on the exhaust manifold burning off.

Power steering fluid is almost the same as ATF. I run ATF in mine actually, cheaper.

 

ps lines sounds like a culprit,
my dad had a truck that would over heat when pulling our trailer and would heat up the trans and puke atf out the dipstick tube onto the manifold and catch fire. (yet it got fixed lol)

 

Power steering fluid. It will steer fine parked, but let it run for a half hour and then try to turn it. When my steering box went (leaked fluid, I just stopped puttng fluid in because I have a new pump / rack waiting to go in, I wanted to see what it was like without P/s) and with no fluid at all it would steer fine for the first 10 minutes or so and then when it heated up it would have the issues u described. You more than likely blew a line, it squirted on the manifold, and caught fire. Its also possible that the injectors in that area were not seated well or had bad o-rings.

What would I do?
-Pull both manifolds. Unbolt the fuel rail, unbolt the intake/ehxuast manifold, take the throttle body off / related sensors, and check all the wires for all the fuel injectors, CPS, TPS, IAC MOTOR, and MAP sensor.

-Replace all O-rings for the fuel injectors. 12 bucks from NAPA
- Replace manifold gasket. 13 bucks at NAPA
-Check for the DIFF fluid breather tube and see if its anywhere near the exhaust manifold
-While you have it apart, look for the obvious. burnt hoses, intake lines, etc would be obvious.
-Re-install the intake manifold and exhaust manifold and torque them correctly.
-make sure all the ports for the injectors are clean and dont have any dirt/grime in them
-Put the Injectors in the intake manifold FIRST, make sure they are all seated nice and snug in the ports. THEN you want to pop the fuel rail on to the injectors. I have found this way seats the injectors better and leaves less room for error.

At this point you should have found something obvious. Dont have the attitude that its something that will never be found, or mysterious. There IS a reason why it happened and you have to be open to suggestions and not reject them. Keep an open mind.

While you have the belt off, spin the power steering pump wheel. Is it smooth? Can u feel it grind at all, or does it struggle/show any restriction?

Look at your P/S lines to see if they bust. The two lines coming off the steering box located below the p/s pump would be two lines to trace. They sit low by the exhaust manifold so my guess is one of those blew open, but not wide open, cuasing the smoke on the manifold.

Hope this helps...............

 

Thanks to everybody for the excellent support and troubleshooting advice! I'm off on Sunday, so my ops start Sunday morning, early. I refuse to give up on my Jeep! It actually bears a significant value to me as well as mechanical. It's not going anywhere but back on the road.

Of course, if anything else comes to mind, please send it - and when I get it solved, I'll definitely post what occurred on here.

* * *

So...gathering from all of your advice, I'm starting to think there's two things happening here. Looking at where all the oil is, and being that there's a little bit caught inside the top of the oil fill cap, I think that, aside from the PS spraying behind and underneath, transmission fluid may have also shot out of the dip stick tube. The power steering system failure would not cause the car to feel like it's in low gear, would it? What vtfd330 said, I think might be what also happened. After fiddling around with the 4wd, it felt like it was in low gear, like as if I was driving a standard, going 40mph in 2nd gear. Every time I let off the gas, it drew back and as I came to a stop, it gave me that winding-down-gear sound, until the last time I stopped, when that awful, extremely loud, rubbing sound began. That last time I stopped, it started with the whine, then as I got to under 20mph, the rubbing sound happened. That's when I thought my transmission was going out - and then the smoke and flame.

And in the three years I've had my Jeep, I haven't thought to change the fluid in my differential, but now I know. When my Dad had it, he might have done it, but I'm not sure, and I can't really ask him right now, because he passed on. So, that will be added to my ops.

[I feel bad brain-pickin', like I'm a shoulder scientist or something, lol, but I'll do anything to get her up and running again, you know?]

 

The whine was your steering pump running low on fluid.

There is a tranny line that runs in to your radiator. Im going to tell you right now the only way your going to figure out whats wrong is just go look at everything. Inspect all lines running out of the radiator. Inspect them all the way back to the transmission. Inspect all steering lines.
CHECK FLIUDS.

Try Changing the transmission fluid and filter.

Good luck.

 

...Could a problem with my transfer case cause some sort of pressure build-up within my power steering system? Could it bust any other lines?

 

No. What is it leaking? Is it trans fluid or power steering fluid?

 

No. Just go look at it. Stop trying to guess.....

 

Okay. Found a problem. There's a hairline crack on my header. I'm pretty sure that is where the smoke was coming from. It was coming up through the point I identified in an earlier pic.

..but that still doesn't explain all the oil on top of my engine

I'm still in the process of checking all the lines and hoses for the fire hazard problem.

 

That is a possibility, but all the XJ headers crack including mine and ive never seen it smoke because of it. Sounds like you just found another problem Welcome to XJ world

 

Finally got it back from my mechanic, who gave me the following diagnosis: When I placed the Jeep in 4wd and back to 2wd, it never came out of 4wd. When I took it to 60mph, I caused alot of pressure within my differential, because my differential is going bad, and the fluid spit up and out via my differential vent tube, which is located behind my power steering fill canister. There's a dry fluid stain on the fire-resistant coating under my hood right where the fluid was spitting out. He cleaned my engine, and told me not to put it in 4wd anymore until I decide I want to change out my front differential.

And he did this for no charge. Sweet deal. Thanks to all of you for your troubleshooting advice.