I have a 5 hp submersible which turns on @65 psi and off @85 psi. When it kicks on there's another "pop" a split second later which rattles the pipes outside the well housing.
Any clues??

Possibly a check valve leaking?

I have a 5 hp submersible which turns on @65 psi and off @85 psi. When it kicks on there's another "pop" a split second later which rattles the pipes outside the well housing.
Any clues???
You're a wee bit high on your pump pressure. Crank it down to 30/50 PSI on the control box, (see image) Let me show you how to reset the control, First turnoff the power at the breaker box, then pull the cover off the pressure switch and you will see two spring loaded bolts secured with nylon nuts. One tall, one short. To increase the cut in pressure, turn the nut on the tall bolt down. To increase the cut out pressure,(that's the one that will give you more pressure) turn the nut on the short bolt down.
Or you could simply install a air chamber,(see image) to cushion the shock.
Another thing to check would be the bladder tank. The bladder might be ruptured. To check, just knock on the side of the tank starting at the bottom. If it "klunks" the same all the way up the tank is water logged. You could try injecting air in at the valve but if the bladder is ruptured it won't take care of the problem. The answer is to replace the pressure tank. Hope this helps and thank you for rating my reply. TOM