ALL THE TIME. I've had rod knock twice on a built engine and most recently a cracked cylinder head, there is not much that hasnt been replaced on my car sadly. I've been down your road many times. Long ago I got a s14 240sx to daily drive and a moded s13 to beat on and auto-x. Now it too has rod knock. So i'm back down to the one s14.
Engine problems suck and are expensive even doing your own work. If you want to keep the car just take your time with it and keep your head up. But look into a daily driver. I like the 240sxs, and i think my moded s13 was faster than my stock NA z32 to a point.
Sometimes I think a car has bad karma and I think its best to rid of it before it comes a money pit of almost 40k.
