• RME Gear & Apparel

Will old gas cause white smoke?

DevinB

DevinB

I like traffic lights
Location
Down Or'm
My Wrangler has been sitting for over a year. I've started it once every few months and let it run for a while and never noticed anything odd. Today I started it up and it's blowing white smoke - lots. The gas is around 15 months old. If it's not bad gas, apparently coolant in the engine causes white smoke. I hope it's not that!

I'll go put some stabilizer in there later today and fill it up with new gas, hopefully that will help. But if someone knows the answer and can calm my fears, let me know!

Thanks-

Devin
 
Cascadia

Cascadia

Undecided
Location
Orem, Utah
I don't want to cause fear or stress but in my experience white smoke has always been a head gasket. I'm not sure about the old gas but let's hope that it is the gas.
 
jackjoh

jackjoh

Jack - KC6NAR
Supporting Member
Location
Riverton, UT
Hope it is bad PVC valve or worn valve stem o-rings instead of water in the combustion chamber by bad head gasket.
 
DevinB

DevinB

I like traffic lights
Location
Down Or'm
How do I go about diagnosing what the problem is? Start tearing into the engine? I've never had an engine apart, I wouldn't know the first thing about fixing any of what you guys have mentioned. Are we talking some pretty expensive and extensive fixes? I've been dreaming of putting in a Chevy 5.3L, is this my chance to justify the cost?
 
JeepinGuru

JeepinGuru

Show em ( o Y o )
Location
WesternSlope, CO
X2 head gasket

things to try...
Smell the white smoke thats coming out of the tail-pipe and see if it smells like Anti-Freeze being cooked.
cylinder leak-down test
look in the radiator. If the water looks like chocolate milk
combustion leak tester. Very easy to use. Probably at any auto parts store
or
(if the engine has been running for a while and it’s hot... let it cool down for about an hour, since a Radiator Cap should never be removed with the engine hot.)
remove the Radiator Cap and then crank and/or start your Jeep. What this test will confirm is if the Head Gasket is letting Engine Compression into the Cooling System (Radiator) or not.
This will produce one of two results:

1.) The water or Coolant inside the Radiator will shoot up and out of the now open Radiator. (This is not good and indicates beyond a shadow of a doubt that the Head Gasket is blown on your Jeep)

2.) The Coolant will not be disturbed. In other words, cranking the engine will have no effect on the level of the Water or Coolant in the Radiator.

Repair
Pulling the head isn't "hard" but it is time consuming and you have to be methodical. The cliff notes version: You have to unbolt the intake and exhaust manifolds, pull the valve cover, unbolt any accessories bolted into the head, and finally unbolt the head itself and lift it off. it isn't horrible, but more than a can of fix-a-flat.
 
Last edited:
gijohn40

gijohn40

too poor to wheel... :(
Location
Layton, Utah
I have a compression tester and a leak down tester as well... I am getting pretty good at taking a head off the jeep... I did mine today in 2.5 hours... but my bolts are all fresh (not rusted in).

Usually white smoke is coolant being burnt.....
 
cuban b

cuban b

You're all WEAK SAUCE!
Location
pleasant grove, UT
white smoke can also be oil. Maybe stuck/broken rings from sitting. cranking with the cap off may disturb antifreeze either way, since the water pump is turning. It may tell you something but it's not really a definitive test. Definitely check the condition of oil and antifreeze. Beyond that, leakdown and compression tests are the way to go.
 
JeepinGuru

JeepinGuru

Show em ( o Y o )
Location
WesternSlope, CO
cuban b said:
white smoke can also be oil. Maybe stuck/broken rings from sitting. cranking with the cap off may disturb antifreeze either way, since the water pump is turning. It may tell you something but it's not really a definitive test. Definitely check the condition of oil and antifreeze. Beyond that, leakdown and compression tests are the way to go.
Click to expand...

you may see the coolant "flowing" with the engine turning and thats typically if the t-stat is open to allow flow, as with a bad head gasket it will "push" or "blow" the coolant out of the filler neck as if you added compressed air into the cooling system.

X2 burning oil appears bluish or a whitish blue
 
Last edited:
L

littlyota

Active Member
Location
Roy, Ut
JeepinGuru said:
you may see the coolant "flowing" with the engine turning and thats typically if the t-stat is open to allow flow, as with a bad head gasket it will "push" or "blow" the coolant out of the filler neck as if you added compressed air into the cooling system.
Click to expand...

Not doubting you, and makes sense in theory, but I have never seen this happen.
 
DevinB

DevinB

I like traffic lights
Location
Down Or'm
Cuban b and I got into it this morning. Turns out it wasn't white smoke but blue smoke, so we didn't have to worry about a bad head gasket. Just to be 100% sure, we drained a bit of oil and it came out clean. We then got a compression tester tool thinger from Auto Zone and checked the cylinders. They were all within spec. Without anything else to do, we drove it to the gas station, put some fresh gas in it, then drove down the freeway a few miles and back. When we got back, no more smoke! So happy it wasn't something major. And now I know how to do compression tests. So there's that...
 
You must log in or register to reply here.
Top