If the noise is from the carb or(FI) it's a intake valve-OR a pumped UP hydralic lifter could cause that-OR even a piece of Carbon STUCK under the Valve can cause it.OR a bad rocker arm and/or push rod.
Noises are impossible to correctly diagnoise unless heard. Take it to a garage.
bad axle joint or ball joints and turn stops can make popping
A plugged up fuel filter.
If it has a v-lsd it will.
i had the same proplem turn out to be the fuel pump
You might have a blown headgasket on top
A front popping on the left of a 98 Blazer could be the brakes, steering, or wheel bearing. Check all three to find the cause.
for starters, your fuel filter may be fouled.
Valves adjusted to tight. Firing order mixed up.
impala sluggish after second gear
check cat converter if it has 75000 miles or more
The 2001 Chevy Cavalier may need a valve adjustment. Loud valves tend to create a clacking noise which could mimic popcorn popping.
If your vehicle is a chevy, it`s probably a flat lobe on the camshaft (probably number 6 cylinder) If when you accellerate the popping comtinues and gets louder replace the cam and timing chain
either your timing is off or your valves still need adjustment
You would need a ported source for the distributor, constant for a pcv valve, constant for power brakes, and constant for transmission modulator if automatic.
check fuel pressure while accelerating if it drops replace fuel filter. these filter are small and clog fast if there is more then 20k miles on filter its clogged. if pressure check for codes and go from there
front struts berings
Could be a faulty spark plug or spark plug wire.
Check heat shield on catalytic converterTry going to a higher octane fuel
Two front driving constant velocity axles
Loss of power, smoke, knocking noise, popping noise, backfiring through carb, or out tailpipe. Any, or, all of these.
Not 100% on this but I would pull the plugs and compare them to [http://www.hioutput.com/tech/plug.html These Images].But it sounds like your van is misfiring and the lose of oil pressure could indicate several things like worn bores/piston rings or valve guides. Good Luck and Remember.Change Your Mind, Not Your Oil.Use the First In Synthetic Motor Oil's.See My Bio For more information.
you might want to check your left side wheel bearings
Sounds like the muffler fell off.