2005 Nissan Altima overheats, returns to normal

About a month ago my car completely died, I replaced the fuel pump, now a whole other problem has started, My car while idling in park or neutral runs just fine, when im in drive, the engine knocks occasionally especially in stop and go traffic or at a red light, and the engine will over heat for a second and then immediately return back to normal temperature, does anyone know what is going on with my car?

Sounds like either the thermostat is sticking, you have air in the cooling system, or the cooling fan isn’t operating properly.

I strongly urge you not to drive it anymore until you get it diagnosed and repaired. Have it towed to a shop. That knocking may be your engine shouting “STOP; you’re killing me, I can’t keep my rod bearings properly lubricated because the oil is overheated and as thin as water.”

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If it even has oil in it.

Good point.

I’m guessing a problem with the radiator cooling fan. For the most part it only spins in stop and go traffic, not during higher speed driving. The noise may be the fan blade hitting something (like the radiator), which prevents it from turning, so the engine heats up. then the blade becomes unstuck, and it cools back down again. Just a theory. Next time this happens, pop the hood and take a look at the radiator fan. If the engine is overheating, the fan should really be spinning like crazy.