Knocking

Just wondering if anyone's experienced this.

First let me start by saying, I'm no mechanic, but I am a fixer, or at least try to be (before resorting to a drastic send it to the shop to be fixed).

Anyway, I'm recently hearing this knocking sound in my Geo Storm. At first, I thought it was the engine, but then I thought that if there were something wrong with the engine, wouldn't it be a constant knocking? It only happens when it's on drive AND after you let go of the accelerator. Normal drive does not produce this sound. Also, on engine idle, there's nothing. I've looked under the hood, everything seems to check out. I'm ready to jack the car up and go under. Since this will be the first time for me to do something like this, is anything specific anyone can point me to that could potentially cause this knocking sound?

Thanks!

Could be the rod bearings. Check out Stormowners.com or Isuzone.org There are many very knowlegeable people over there that will be very glad and able to help you. Is it an auto or manual. I'm assuming automatic since you said it only happens on drive. Either way, if you post on those beards mentioned above they will need to know details like year 90-93, model, base/GSi, and possibly more, but that's basically the advice I'm giving you is check there.

if its more of a clunk check the bushings at the back of your lower control arms i dont know the technical name but ive never ever seen a storm that didnt need them in one way or another if there not the root of your problem go back to basics and wiggle everything under the car, bang on the cat check exhaust hangers and inspect all wheel bearings adn front end parts then check the motor mounts <put in drive with foot on brake and accel slightly watching engine for excessive movements then try the same in reverse. if all else fails a storm does have one of the cheapest auto trans torque converters ever built good luck

I've heard loose torque converter bolts sound just like a rod knocking...