1990jeepxj

So I was driving on the highway today and my jeep started to pour white smoke out of the exhaust pipe. I was about to pull over and then it stopped. What could it be? Its running fine now and no more white smoke! I searched but all I could find was continuous stuff. I also used Marvel Mystery Oil in my last oil change if that would affect anything.

Firestorm500

White smoke is usually burning antifreeze. Watch for unexplained coolant loss.

A tremendous amount of oil all at once in the combustion chamber can look white, too.

1990jeepxj

Ok, would it continue to smoke if it were coolant? Could there have been something I did that would cause that much oil in the combustion chamber?

Firestorm500

Overfilling of the oil maybe?

There shouldn't have been any need for MMO. Just 6 qts of oil and a good (not Fram) filter should be just fine.

McCaffrey

Both water (coolant) and oil normally make white smoke.

- Water = Odorless and dissipates quickly.
- Oil = Sweet smelling. Use this in your spy car to make a smoke screen causing everybody behind you to crash and curse your name.

ZINGGG

When you saw the white smoke, did you happen to take a look at your temperature gauge to see if that was affected at all?

Like said above, burning coolant could cause white smoke.

Radi

You sure it came from the exhaust and not something urping up onto the hot exhaust? Might have a look underneath.

Firestorm500

I wondered the same thing. He may have just assumed it was coming out of the tailpipe itself.

Could be his transmission fluid is overfull, or it got too hot and came out of the dipstick tube.

jebmccall

oil does not smell sweet... atleast ive never smelt sweet smelling burnt oil

coolant has a sickening sweet smell to it when burnt.

have you checked you're coolant level yet? transmission?

RTorrez1

You are correct Sir.
The coolant is the one that has a sweet smell and burnt oils smells like burnt oil.
If you are still having the problem start her up let it get warm and look under it and make sure that it is coming from the exhaust and not from somewhere else like a leaking gasket or trans. Keep use updated on what you find. Good Luck.

sthon

^This. Did it happen to get worse when you would let off the gas while coasting? Check your exhaust near the bellhousing, you could have been dumping ATF on your exhaust. If that's the case it should be easy to see the burns.

McCaffrey

hahaha. I'm sort of shocked you guys don't think burning oil smells sweet. Maybe I've inhaled too much exhaust.

sthon

Or you have coolant leaking into your oil.

Firestorm500

Maybe you've been inhaling too much of something else.

1990jeepxj

Ok, so the temperature guage was a little over 210. I was also driving up steep grades so that may have affected it. I had oil all over the side of my jeep when i got to my destination so that may have been what was burning on my exhaust. My friend also had it and he was in front of me confirming that the oil was not from my jeep. I have not checked my fluids yet. I will tonight though.