I own a 1995 Isuzu Rodeo 3.2 6L 4x4

I'm not sure if all this related, but I want to be sure that I put everything on the table. Of each incident listed below, there were no signs that anything was going bad.

• I hit a bump while driving.
• The fan stopped working and the seat-belt light, gas light, and battery light came on and stayed on in error.
• The battery voltage became low.
• Neighbor replaced the Alternator.
• Above problems fixed.
• Went for test drive.
• Trucked started to stutter and rattle.
• Neighbor replaced 2 Coil Packs because one plug out of each pack wouldn't spark.
• Truck ran GREAT. The best since I got it about 5 years prior.
• Next morning, I leave for a long trip.
• After driving for about 20 minutes at 70-75mph, I begin to her a few pops.
• Sounds like it's coming from the back of the truck.
• Five minutes later, the pops becomes louder and more frequent, like popcorn.
• I slow down to about 60mph, it stops.
• Go to mechanics.
• They change plug wires and other Coil Pack (I already have new Spark Plugs from January).
• I leave.
• I get to about 70mph, it starts again. Sounds like the pops are now coming from under the dash.
• I return to mechanics. He rides with me. He believes the sounds are coming from the roof.
• We pull over and adjust the Roof Racks.
• We drive and the pop starts again.
• When we return to the shop, they remove the Roof Racks, a loose Mudflat & tighten the radio antenna.
• I leave.
• The sound returns. This time at about 30mph.
• I go by a different mechanic and let him listen from a video I made. He doesn't know, and kind of laughs.
• I return home.
• I disconnect the stereo, didn't help.
• From the driver seat, it sounds like the pops are coming from under the dashboard on the passenger side.
• When I lean my head over to the passenger side, it sounds like it's coming from the roof. 2 mechanics agree.
• I have no sunroof or any significant there.

The pops are frequent like popcorn, they sound like someone tapping their finger nails on the roof, but a little more electric & deep (just a little). Almost like the sound of lifting a Coil Pack while the engine is running. They are loud, very noticeable. Driving behind a Semi-Truck on the Interstate made no difference either way.

There are no lights flashing and the truck runs great. It's just the sound.

I would dismiss it as something loose if not for the fact that both the Alternator and Coil Packs went out the day before.

In the last 6 months, I've gotten a new Timing Belt, Water Pump, Alternator, Tires, o2 Censor & Plug Cables.

Could this be related to when I hit a bump? Maybe the tires are out of balance, though the bump wasn't too bad and it doesn't explain the other problems.

Any thoughts?

 

Update

It took a 13 year old to figure out what four 4 mechanics couldn't - not to mention the $300 in unnecessary parts, a full day, a tank of gas and a lot of stress. Turned out being the strip between the front window shield and body, it was loose. Nothing a little duck-tape can't fix until I get to a store.

Just wanted to update this post in case somebody else has the same problem.