Emergency! Loud BANG noise!

[hulk311]

I was going 60mph with cruise control on the other day on the highway when all of a sudden I heard a VERY loud bang (actually two of them) from underneath my truck, it seems to come from the back. The truck continued driving with cruise control with no hiccup at all. The two loud bang noises shook the whole truck and I thought that my tailpipe or muffler exploded.

I pulled over and glanced underneath my truck and the tailpipe and muffler were still there. Does anyone have any idea what these two loud noises were? They sounded and felt like somebody took a 100lb sledge hammer and hit underneath my truck. Could it be some kind of bolt that was connected to some high pressure pipe got loose and shot out and hit the truck?

The truck seems to be driving ok with no problems as well as there are no engine codes on.

 

[TechWrench]

I was going 60mph with cruise control on the other day on the highway when all of a sudden I heard a VERY loud bang (actually two of them) from underneath my truck, it seems to come from the back. The truck continued driving with cruise control with no hiccup at all. The two loud bang noises shook the whole truck and I thought that my tailpipe or muffler exploded.

I pulled over and glanced underneath my truck and the tailpipe and muffler were still there. Does anyone have any idea what these two loud noises were? They sounded and felt like somebody took a 100lb sledge hammer and hit underneath my truck. Could it be some kind of bolt that was connected to some high pressure pipe got loose and shot out and hit the truck?

The truck seems to be driving ok with no problems as well as there are no engine codes on.

Maybe you just ran over something in the road that you didn't see?

 

[Rix]

There's really no way to even begin guessing with so little information.
Might be worth it to have the truck racked and take a look under it.

 

[Tomsriv]

If the truck is running fine I would think you hit something. The only way to do that in the exhaust is to have the spark plug fire on the exhaust stroke.

I did that once on my Buick, removed all the plugs to do a compression test. The carb sucked a lot of unburned gas into the exhaust system. When I put the plugs and wires back on I got one switched around. It fired on the exhaust stroke and the BOOM was so loud my neighbors came out to see if I was ok. I could hear dogs barking blocks away.