Vannin' Home Forums General Discussion General Discussion erratic popping snapping sound

Erratic non-continuous popping / snapping type sound in the van. Mechanic took a look today and doesn't know what it is. Checked mufflers & nope, checked ujoints and they are good, is it the transmission?, or the teeth in the rearend? Keep in mind its not continuous and seems to happen under load when I am on the accelerator....???

Welcome! My experience with Chevy's is limited, I own Dodges now. It might be the cam shaft or even bad gas, just my 2%. Had the camshaft thing happen to one of my Chevy's,did the same thing.

can you point where it's coming from at all. The front or rear? if it's the rear then may need axle work, possibly the brakes... but since under load I'm almost at a loss here, is there any sort of backfiring or misfiring? is it consistent or just random rattling? If it's random rattling I couldn't tell you other than it could be the catalytic converter is stuffed and needs replaced, if it's consistent with RPM's then it's something within the motor but under a load could be tranny. sorry I'm not much help but that my 1 cent.

Bubble wrap stuck under the gas pedal?

Timing chain skipped a beat? Gets worse under load ?

The sound is for sure coming from the driveshaft area. Its not really really loud but loud enough to hear at 45 mph. Whats funny is its bad one day and the next not. But the other day on hwy it was really bad. So I know what ever the problem is that its getting worse. Its the type of sound that an experienced mechanic should be able to hear and know what exactly it is. I really hate for it to be the tranny. The ujoint sounds that I am hearing on youtube are not at all like the crackling popping I am hearing.

HMMM Doc thats the first someone has mentioned the timing chain. I'll make sure to check that.

I did sometimes get a "metallic rustling" sound under a load in my Dodge. For me, the sound was attributed to a weak motor mount allowing the engine to torque twist enough for the headers to come into contact with the heat sheilding around the floor pan. There may be other het shields that are loose or coming into contact with movign items. Just another thought for whatever it's worth...
look for anything that may be loose, or see shiny metal anywhere that things may have been rubbing or bumping together...
Best of Luck...

Neighbors cat?????...