R Cannon

The coolant looks brown. White smoke coming off of the cat. water out of the tail pipe. Please help. Water Pump was changed 2 months ago. So I know the PO used new coolant.

irs009

Oil should be foamy if the head is cracked or bad head gasket.

R Cannon

I pray its the gasket. I have an extra head from my 96.

No4x4Yet

Id do a leak down test to be sure of the problem before you start to pull stuff apart.

R Cannon

How?

R Cannon

CodeXJ

Brown coolant is NOT oil in the coolant. Rainbow colored coolant is water in the coolant. Brown coolant is just some moron using the wrong type and it reacting with the metal, making sludge. You need to flush the cooling system and hope that the radiator isn't clogged.

Now, if the oil is milky looking (thinky a foamy chocolate milkshake), then you've got issues. Some water and white smoke from the exhaust is common, especially when the engine is cold, this is just condensation. If the smoke smells sweet, however, this is coolant and not just condensation. Remember, water vapor is actually a byproduct of combustion.

Is the engine running bad?

Wait, you said smoke from the cat? Like, from under the vehicle and not the tail pipe?

R Cannon

Im starting to think valve seals. Its not losing coolant. Sounds like Flush Flush Flush? Oil looks great on the stick. No rainbows in the rad. I think you nailed it. Thanks. Engine runs great.

CodeXJ

So the smoke is coming out of the tailpipe, not out from under the Jeep?

My '93 has bad valve seals. It's interesting, she doesn't smoke 99% of the time, but if I'm sitting at a long light or a drive-thru, she starts to smoke a lot. Bluish smoke is oil smoke. However she runs great and uses very little oil (1 quart ever 3k miles or so), so I've never pushed the issue. She'll be getting a rebuilt motor sometime later this year, since I've got a spare now.

If the smoke is coming from under the Jeep, I'd be willing to bet it's nothing more than a bad valve cover gasket leaking down onto the exhaust. They tend to go bad at the back of the valve cover, oil leaks down the back of the block, over the transmission, and onto the exhaust. Viola, smoke.

Yeah, flush the hell out of that cooling system. Mine was like that as well, took two flushes to get it decently clean.

rich

Thats just dried out vaule seals. No biggy little smoke when idling and maybe at start up will never hurt anything.

No4x4Yet

If you have a compressors buy a leak down tester off Harbor freight, otherwise a decent mechanic should be able to do one for you. I had a compression test done on my mustang and it was perfect, but a leak-down test showed 30% leakage on the #3 cylinder.

CAEMI

I'd use http://www.aircraft-tool.com/ to buy a leakdown tester. They're like $50 but it is a real tool - quality tool. I don't trust Harbor Freight.

Comes with instructions, too.

R Cannon

I'll "Git er done" Neighbor has a compression gauge. And the part to charge each cylinder to do the valve seals. The wierd thing was that it wasnt smoking from the tail pipe. Just the outside of the cat. I have a tranny pan leak. It only smokes after rolling down the road after heating up. It could be the seafoam?I have a feeling that the block and head had crud in it. I flushed the system with the prestone stuff that has to stay in for 8hrs.

Caish

Valve seals are easily changed,
Need:

• Air Compressor
• Air hose
• Spark plug adapter for air hose
• valve spring compressor
• New seals.

Remove the valve cover
Get the first cylinder to TDC compression stroke.
Attach the air adapter to air hose and screw it in the hole.
Turn on the air, the engine will rotate to the bottom of the stroke,
Now the air will hold the valves shut and you can use the valve spring compressor to compress the spring and pick the retainers off the valve and lift the spring off.
Slide the old seal off and slip the new one on. A drop or two of oil would be a good idea.
Set the spring back on the valve and slip the () retainers back on the valve and gently release the spring pressure watching the retainers don't move.
Now got to the next valve and repeat.
When done with that cylinder remove the air adapter and I will use a small hammer to gently tap the valves to make sure the retainers are fully seated.

Basically all there is to it. I've done many of them the very same way.

:edit I forgot to add:
BTW it is possible for an engine to crack head in such a way that it puts water in the exhaust without ever seeing it in the oil. This can be checked with a pressure test on the radiator. Pressurize radiator to 16 to 18psi and see if it leaks off, then you have to find out where its going.

Side note on Valve seals, there is typically two times that seals leak, after the car sits overnight and you first start it, it will smoke a little till it burns the oil off, the other is with increased vacuum when decelerating will cause it to smoke.

R Cannon

Thanks Bro! If it aint broke dont fix it. Those seals are going to be changed ASAP. Thanks to those your great instructions.