Gust of smoke / steam? not sure what it was...

[Infidel Edition]

OK. So I'm driving my monthly 285 mi. trip to drill weekend.
It was a nice day in the mid 70's and the temps (assuming the gauge is on the money) was right around 195° / 200°
Averaging 60 to 65 MPH.
About 175 miles along and headed toward the pass, there was a stop where they're working on the road, and as I roll to a stop I notice a bit of what I assume was steam out the front... then a good puff of steam / smoke out from the passenger side front wheel area.
The gauges were all good range and the traffic started again with no good place to pull over.
So I went another 3 - 4 miles to the rest area.

Popped the hood expecting to see where the ??? was coming from.
Nada? No wet spots... no smoke... no signs of anything.
All the fluids were as expected.

I checked all the hoses ~ and the felt good and secure. I'm still gonna change 'em eventually...
I have noticed around the head cover gasket that it looks like some seepage. But it has since I've had it (2 months now). Could it be dribbling oil there when hot-hot and smoke?
**there is no water in the oil
**it idles fine
**still pulling 25+ MPG

I did notice a blast of smoke on the passenger side once before too. I was against the curb and gunned it to pop up on top... and got what I though was tire smoke from the old bald tires.

Anyone know what's broke now?
I'm gonna swap the head cover gasket when I swap the rear main seal next month ~ I've noticed oil dripping out from the bell housing just in front of the clutch. I generally lose 1/2 at per 150 miles...

[XJ Wheeler]

I'd bet its that oil you're loosing. Just get under there and give it a real good look, oil should be noticeable. Just from what you've written there's really no way to tell what it is, just help you find it.

[ArmyGuy45]

How do you get 25mpg in a XJ?

[Infidel Edition]

How do you get 25mpg in a XJ?

I've got no clue...
3.07 gears with a 5 speed manual. Yes, it's a 4.0
65 MPH = 2100 RPMs +/-

The MPG drops about 1 MPG for each 3-4 MPH over 65.
And most of the trip is open freeway. So no stop/go traffic. But I do go over the pass.

[Brasscatz]

I was getting this a lot and it was transmission fluid that was leaking from my transfer case and hitting my exhaust. Also, passenger side wheel area... I'm thinking coolant reservoir leak somewhere? .... unless your Jeep likes the occasional cigarette from time to time on long trips ;)

[prcjeep]

You only notice this when coming to a stop? I say its a brake dragging do to a semi-seized caliper piston and once stopped you see the smoke. This has happened to me several times.

[Cheromaniac]

I have noticed around the head cover gasket that it looks like some seepage. But it has since I've had it (2 months now). Could it be dribbling oil there

I'm gonna swap the head cover gasket when I swap the rear main seal next month ~ I've noticed oil dripping out from the bell housing just in front of the clutch. I generally lose 1/2 at per 150 miles...

I think the oil dripping out from the bellhousing could be coming either from the rear main crank seal or the oil pan gasket (my money's on the first), and that's running onto the exhaust crossover pipe where it's being burnt off and causing the smoke. You'll need to replace the oil pan gasket regardless because you'll need to remove the oil pan to replace the rear main seal. While you're there, you can consider replacing the oil pump and the rod/main bearings so you can kill several birds with the same stone.
Oil leaking from a valve cover gasket won't leave smoke on the passenger side 'cause the header is on the opposite side, but it'll make a nice mess of your engine so it's best to replace it anyway.

[Infidel Edition]

I was getting this a lot and it was transmission fluid that was leaking from my transfer case and hitting my exhaust. Also, passenger side wheel area... I'm thinking coolant reservoir leak somewhere? .... unless your Jeep likes the occasional cigarette from time to time on long trips ;)

I need to clean out the area under the coolant res... there is a lot of rusty/brown looking (but dry) residue. And the reservoir looks a little stressed like it's going to blow at any minute... But it was dry. ** Going to change those lines next weekend.
The only apparent leakage is just under the bell housing unit. But I'll clean that thoroughly and then see if anything creeps out... I assumed it was the rear main seal.


You only notice this when coming to a stop? I say its a brake dragging do to a semi-seized caliper piston and once stopped you see the smoke. This has happened to me several times.

It has only happened 2 times in 3 months. But I guess it could be the piston. Hadn't thought of that. I just replaced the pads, and the old ones didn't have any obvious extra wear.
I was planning on changing both front calipers last month when I swapped out the hubs ~ but had to put that off due to $$ going into fixing other things first.
Summer project is to rebuild / replace all 4 of the wheel's breaks. Guesstimating it'll run me around $100 / $150 as long as I don't need to get new disks or drums.

[Infidel Edition]

OK. So when I pull the valve cover off and redo the gasket...
Do you guys/gals go with a gasket? or straight RTV (ie. high temp red)?

Thoughts?

[bulrid8]

OK. So when I pull the valve cover off and redo the gasket...
Do you guys/gals go with a gasket? or straight RTV (ie. high temp red)?

Thoughts?

Felpro permaseal gasket. No rtv. It's a little more money, but be done right!

Sent from my ADR6400L using Tapatalk 2

[Infidel Edition]

I think the oil dripping out from the bellhousing could be coming either from the rear main crank seal or the oil pan gasket (my money's on the first), and that's running onto the exhaust crossover pipe where it's being burnt off and causing the smoke.

While you're there, you can consider replacing the oil pump and the rod/main bearings so you can kill several birds with the same stone.


It does get more oily with higher temps and drive time... so that would make sense for why it isn't all the time.
and
I hadn't thought about the replacing the others while there.
...good call.

[Infidel Edition]

Felpro permaseal gasket. No rtv. It's a little more money, but be done right!

Sent from my ADR6400L using Tapatalk 2

I've never skipped the gasket before ~ but had noticed a lot of threads saying to go RTV only on things like the valve cover.
I was leaning toward the permaseal gasket... but wanted a 2nd opinion.

[Infidel Edition]

It does get more oily with higher temps and drive time... so that would make sense for why it isn't all the time.
and
I hadn't thought about the replacing the others while there.
...good call.

~Now, to change the rod/main bearings, don't I need to pull the crank?
... and to do that, don't I have to pull a bunch of other stuff too?

[Cheromaniac]

No, you don't need to remove the crank altogether. Just remove the oil pan and oil pump with pick-up tube (you'll be replacing the pump anyway).
Replacing the rod bearings is easy 'cause all you have to do is loosen the rod bolts, pull off the rod caps to replace the lower bearing shells, and push the rods with pistons up just enough to get to the upper bearing shells.
You can replace the main bearings by loosening the main cap bolts and allowing the crank to drop a little. Having a buddy to support the weight of the crank leaves both of your hands free to replace each bearing shell. Comfort and space are important so ideally you'd need to raise the Jeep on a two-post lift so that the front axle can droop and you can stand underneath. Alternatively you could jack the body up and support its weight with tall axle stands under the frame rails and the axles in full droop.

[Infidel Edition]

No, you don't need to remove the crank altogether. Just remove the oil pan and oil pump with pick-up tube (you'll be replacing the pump anyway).
Replacing the rod bearings is easy 'cause all you have to do is loosen the rod bolts, pull off the rod caps to replace the lower bearing shells, and push the rods with pistons up just enough to get to the upper bearing shells.
You can replace the main bearings by loosening the main cap bolts and allowing the crank to drop a little. Having a buddy to support the weight of the crank leaves both of your hands free to replace each bearing shell. Comfort and space are important so ideally you'd need to raise the Jeep on a two-post lift so that the front axle can droop and you can stand underneath. Alternatively you could jack the body up and support its weight with tall axle stands under the frame rails and the axles in full droop.

Cool. I didn't know the crank could move unless unbolted from the flywheel and balance/pully on the front.

[Carves]

Agree on the oil leak onto the exhaust as the likely culprit ... Had the same issue a coupla years ago.

RTV can be good stuff .... but I would bang a felpro gasket in there .. ;)

[Infidel Edition]

So on the drive back to Portland I had some smoke again... but MORE
I was on my way to the gas station less than a mile away. Looked under and lots of oil on the cat.
After it cooled down a bit, I discovered the screw next to the firewall ~ securing the valve cover was almost falling out!
Tightened it and not as much smoke (after the rest cooked off) & I didn't have to top off after another 125 miles.
Gonna swap out the gasket and see if that's my biggest issue