[mtn121]

My 93 XJ 4.0 is smoking, its a white smoke. It smoke sometimes when you first start it, and it is idleing before you take off. The smoke is a whiteish color. Also, when you stomp on it or accelerate fast it blows out the white smoke also. Also when I stop sometimes after driving like in a drive thru line it sarts to smoke. My jeep uses some oil between changes and I have to add some. It has a few minor oil leaks that I am gonna address soon but nothing major. What would be causing this smoke? Is my motor going do I need to consider rebuilding or retiring the jeep if I can't afford to rebuild it. It still has lots of power which make me think it has alot of life left. Are there any products I can try to fix this that might clean it out. What about the seafoam stuff? Any ideas what to try or ideas to explore. Thanks guys

[mtsumedi]

Valve seals??

[tjwalker]

White smoke is indicative of "coolant" (antifreeze) being burned. Take a whiff near the exhaust; sometimes if it is strong enough, you can smell the sweetness in the exhaust.

Step #1 is to check your coolant level in the radiator/reservoir. Check your dipstick and oil filler cap for any indication of coolant in the oil.

Testing that can be performed if you believe you have a leak of some sort include cooling system pressure test, compression testing, and a leakdown test. Head/headgasket could suspect here. Again, testing is the best strategy to isolate root cause.

Has the engine ever been overheated? This can sometimes lead to this type of problem.

[bdb12586]

what he said

[mtn121]

There is no indication of coolant in the oil on dip stick or cap. The coolant seems to get a lil low some times. Could I do any of these test my self? How big of a repair is this?

[LJameson]

Are you sure its white? Or does it have a blueish tint to it?

[tjwalker]

Originally Posted by mtn121

There is no indication of coolant in the oil on dip stick or cap. The coolant seems to get a lil low some times. Could I do any of these test my self? How big of a repair is this?

If you are losing coolant, it is either leaking or burning it. If there are no obvious leaks and with your observation of white exhaust smoke, it might be the latter of the two.

First thing I would do would be to perform a compression test as that is the simplest for the do it yourselfer. You are looking for larger variations between cylinders in the readings you get. Use the SEARCH function for more information along with GOOGLING it. A manual is helpful with this as well as being invaluable for any and all repairs.

Post back what you find if you decide to do some testing.

[98junk]

Sounds like coolant is entering the combustion chamber. Bad head gasket hopefully. One additional indicator is air bubbles in radiator while it is running.
If you have a non pressurized coolant tank.
good luck