Anti Knock sensor question. Why does it rattle under a load?

I have a totally stock 1996 2.4 with the 5-speed. Since I've owned the car when I drive up this big hill to work in 3rd gear the engine starts to knock and rattle. Knowing this could be fatal for an old engine, I immediately back off the gas and shift into 2nd to get up the revs and the knock goes away. This also happens on level ground when I step on it from 4th to 5th.

Is my knock sensor going out, or is this normal?

A few details:
I used regular gas.
New plugs, cap & rotor, plug wires, fuel filter, air filter.
No weight in the truck bed.
This has been going on consistently for 7 years.

I honestly don't know much about knock sensors. Will it still have a little rattling even if the sensor is working good? Thanks for all the help.

 

It could still have pinging if the knock sensors are good. The high gear / low rpm condition you’re talking about is similar to supercharged 3.4 trucks that will get pinging. I want to say it’s because they’re not getting enough fuel. @Speedytech7 ?

 

Thanks. I cant even afford to get a flat tire right now, let alone replace an engine. Good to know its not thar uncommon.

 

When you say "rattling" I'm wondering if you just mean what any engine will do when it's being lugged at low RPM with a manual. Is there an actual knock?

 

Yes, it is a definite preignition knock that will ruin the engine.

 

Got it then yeah 5vz’s will ping regardless if they have functioning knock sensors.