Loud pop, white smoke, now not running right.

[1996BLKBauer]

So I was starting my truck today, and it took a little longer to crank, then I hear a loud pop, and white smoke started coming out from under the hood. I pop the hood and inspect, I see nothing wrong. I go and start it again, it starts, but runs really rough. I go back under the hood, and it sounds like it had a massive vacuum leak. So I shut it off, and now I am at work typing this up. Is it possible that it back fired somehow and popped a vacuum line off the intake, or worse blew a hole in the intake? Idk I am really mad right now because I need the truck to get to school and work for the next week. Any input would be really awesome right now.

The truck in question is a: 1996 Ford Explorer Eddie Bauer AWD V8

 

[1996BLKBauer]

Also a little info on the truck. The right hand down stream O2 sensor is no longer working, I have the sensor but have not installed it yet. The fuel trim is good. Short term is +\-3 and the long term is at or close to zero. So it for sure is in fuel control, although that is not the exact number, I am fairly certain it is close. Also I have had a very small misfire at idle for a long time. I was just going to do a fuel system cleaning, and new plugs and wires soon to see if that would fix it. There are no codes for misfires, only codes for the O2.

 

[1996BLKBauer]

So I am assuming since nobody has any input on this, that it is pretty rare to happen, or it am really screwed. I am really wondering if I am able to drive it to my school which is 10 miles away so I can work on it there, without harming anything on the truck, I really cannot afford to melt down a cat, or something worse.

Once again, any input is great, still freaking out right now.

 

[1992fordgreen]

Sounds like your headgasket...maybe you're lucky and it's something minor...wait for more input before freaking out.

 

[1996BLKBauer]

God, I hope it's not the head gasket. The cloud if white smoke smelled nothing like coolant, but a lot like fuel.

 

[A.J.C.]

Its really hard to diagnose with out being there to look things over but from what you described:

If it sounds like a vacuum leak and idles rough, it is probably a vacuum leak. I didn't have any smoke or check engine light but my explorer ran rough when cold and would make a loud noise which shook the intake hose. I replaced the intake manifold gaskets and idle air control valve. That fixed my issue.

I wouldn't start throwing parts at it, its probably best to have someone knowledgable to diagnose it if you can't. Hope this helps.

 

[1996BLKBauer]

Thanks for the reply, I have had a rough idle for a while, and I am fairly certain that a hose came off of the underside of the intake, problem is that I cannot see under there at all. I am in my advanced drivability class right now at school, so I feel confident working on it there, rather then at work, which is a Buick GMC dealership. But is it possible for an Eco engine to backfire even?

 

[A.J.C.]

Its not very hard to pull the upper intake manifold off to see if any hoses have come loose or have cracks. If you haven't replaced the upper and lower intake manifold gaskets yet, they are under $20 and are notorious for causing vacuum leaks.

I think I replaced mine in under an hour or two. Youtube video of how to: https://www.youtube.com/watch?v=XGKIztH7I8k

 

[1996BLKBauer]

Very cool, if I have to pull the intake, I will do that then. I really would like to just do everything in one shot. I plan on keeping this truck for more then 300,000 miles, so it wouldn't be a bad idea to do this anyway, especially considering I have already had a bad idle problem, and it is prone to failure.

 

[A.J.C.]

For some reason, I thought you had the 4.0 SOHC. Now that I see that you have V8, I still think it could be a vacuum leak caused by the backfire. I would still pull the intake manifold and check for leaks.

 

[swerneck]

Hi, I had the exact same pop and white smoke, and it was the vacuum supply to the EATC unit that got disconnected. Is your fan working or just the defrost blowing air to the windshield?
Just connect the hose and it's back to working order.
I'll try to find a Picture of the hose location.

Sergio

 

[1996BLKBauer]

Hi, I had the exact same pop and white smoke, and it was the vacuum supply to the EATC unit that got disconnected. Is your fan working or just the defrost blowing air to the windshield?
Just connect the hose and it's back to working order.
I'll try to find a Picture of the hose location.

Sergio

You would be my savior if this is the case, I will check the operation when I get home to see what is going on.

 

[swerneck]

Here is a Picture, it's the pipe shaped part with two ¨wires¨

let me know if you can see the image.

The reason for the explosion was that the fuel pressure regulator at the end of the line had a hole in the diaphragm and was injecting fuel inside the header.

Sergio

 

[1996BLKBauer]

Got it! It was not the same issue as you. There was capped off vacuum line at the back underside of the intake, the cap blew off, and fell down into the exhaust manifold. The cap was pretty cracked, and it sort of melted when it landed on the manifold, I bought a new one at Orileys for about $2.50, I re capped it, and it is running great again. Fuel trim looks good, and no crazy codes. So I think that was it. I am taking my truck to school tomorrow, to test the fuel pressure regulator, and to see if the manifold gaskets are leaking, I still do seem to have the slight misfire/running rough at idle. I still am planning on doing a tune up, such as new plugs and wires, hopefully all this will fix the rough idle.

Thanks guys for all the help. I am so glad to have my Explorer running good again.

 

[sookhee]

So I was starting my truck today, and it took a little longer to crank, then I hear a loud pop, and white smoke started coming out from under the hood. I pop the hood and inspect, I see nothing wrong. I go and start it again, it starts, but runs really rough. I go back under the hood, and it sounds like it had a massive vacuum leak. So I shut it off, and now I am at work typing this up. Is it possible that it back fired somehow and popped a vacuum line off the intake, or worse blew a hole in the intake? Idk I am really mad right now because I need the truck to get to school and work for the next week. Any input would be really awesome right now.

The truck in question is a: 1996 Ford Explorer Eddie Bauer AWD V8

You are likely correct about the possibility of having a vacume hose blown off. If it's running real rough It should be obvious. If not, try using a 3 ft. piece of garden hose. put one end to your ear and snoop arround with the oter end for the sourse. Watch out tor the fan!