1996 4.0 blowing white smoke

[Jim Oaks]

A week ago I was driving home after having a friend weld together a plow frame that was bolted on the front of my Ranger (I didn't have the blade mounted on it). As I was going up a grade I noticed the truck seemed like it was losing power.

When I got home I noticed that the truck was idling rough, and have since noticed a lot of white smoke from the exhaust that smells like burning oil. I actually first thought that it was from a bunch of old gas I dumped in to it, but it still smokes after putting fresh gas in.

I also noticed the transmission seems to shake before it shifts and just seems a bit off.

So, I need to get to the root of the problem. I know people will be quick to say it's a head gasket since it's blowing white smoke, but I'm thinking it could possibly be a bad PCV valve (or the engine is somehow sucking oil in to the intake), or a bad transmission modulator possibly letting transmission fluid get sucked in from a vacuum line.

I do know I've had a vacuum leak, because my heater is stuck on defrost, and I haven't located the leak yet.

Any thoughts or opinions?

 

[RonD]

There is a very simple test for a head gasket/cracked head issue.

The glove test:
Cold engine
rad cap removed
Overflow hose removed
Unplug Coil, you want a "no start"

Put Latex glove or balloon over rad cap opening, seal it with rubber band if needed.
Block overflow hose opening, vacuum cap or finger will work.

Crank engine and watch the glove, if it moves you got a leak from cylinder to cooling system.
Glove will bounce each time the leaking cylinder is on its compression stroke.

Video of a Glove test here:
http://www.youtube.com/watch?v=vFGquUimXro&feature=youtu.be

He found a new type of "balloon" to use , but it worked, and he did have a blown head gasket.

If your "glove" moves then you can find out which cylinder is leaking by removing 1 spark plug at a time, and cranking engine each time, when "glove" stops moving the last spark plug removed was the leaking cylinder, put it back in to confirm.


White "smoke" with a smell will be a blown cylinder seal, either gasket or crack, 99% of the time
But "bad" gas is bad because it has too much water in it, and that would blow white as well, especially after truck sits; water is heavier than gas so will settle at the bottom of the tank when truck sits, when started the fuel pump pulls in the higher water content fuel, so you get the white smoke, but that should go away after driving and water gets mixed with the fuel, so % of water goes down.

Blue "smoke" would be oil/trans fluid, worth pulling the vacuum line for modulator and have a look for oil
Black "smoke" is excess fuel

Glove test is free, so I would do that first, to get it off the table as the problem.

Rough idle and noticeable shake when shifting could be cylinder misfiring, that would happen with a blown gasket or water in the fuel.
You may also notice a higher level in overflow tank with engine running or a bubbling in that tank, then a lower level after shutdown and the engine cools down, that would be a blown head gasket.

 

[Jim Oaks]

it's definitely white smoke.

Vanessa and I removed the gas tank from her Ranger (Still under construction), and the gas has been in it for at least the (3) years we've had it, plus however long it sat with the previous owner. I put about 6 or 7 gallons of it in my tank which gave me a 1/2 tank. I initially thought that it could be the problem, but it quickly started looking like it could be something else. I'll have to find something to do the test you described.

I really didn't want to have to do any mechanical work on it until spring. I just needed it to get me through the winter plowing my driveway.

 

[RonD]

Plastic sandwich baggie will work; pretty much anything that will show if "air" is being pumped into the cooling system by a cylinder.


If it is a cylinder leak I have used Rislone head gasket "fix" on two engines and it worked.
One was on a V6 and it lasted 6 months until there was time(and temperature) to put in new head gaskets, it was actually a cracked head.
Second engine was a 4cyl and it work for over two years until tranny gave out, neighbors car, he junked it.

So it would get you through the winter.

And just for the nay sayers, I was once like you, been wrenching for 30+ years, lol, but thought what the heck.
If I had a heated shop and all the time in the world I probably wouldn't have tried it, but I don't.

When I disassembled the V6 there was no blockage in heads or block passages, even the rad and heater core had good flow, no sign of clogging.
Head gasket sealer is different than "radiator stop leak" which I still won't use, pepper is what I use, lol.

 

[Jim Oaks]

So, I did the test with a rubber glove, and it didn't inflate.

I had my wife start it and it wasn't smoking nearly as bad as it was last night when I went to put fresh gas in it.

Still runs rough though.

Here's a video:



I checked the fluids. Oil looks good. Dark, not milky.

Transmission fluid looks like it could be a good 1-1/2 quarts or more low. Don't see where it could be leaking.

 

[RangerSVT]

Your 96 trans don't have a vacuum operated modulator, its all electronic, so you can rule out trans fluid in the motor. I believe you have some water in the tank or lines. Get some heet, and a fuel filter. Add the heet, run for about 10-15 minutes, then change fuel filter...

SVT

 

[Jim Oaks]

Well, there you go.....

Thanks!

Hopefully that will fix it. I need to find another 4.0 that I can rebuild to replace this one by summer.

Wonder where my transmission fluid is going, because it's not leaving any evidence of leaking..... (?)

 

[RonD]

Good news about the head gasket

You could also siphon the gas tank, then let that gas sit for a few days so the water settles out at the bottom, then pour it back in, slowly, leaving a little in the can, mostly water.

Heet does work great, I just like free stuff