79 trans am knock

[lee2]

Hi i have a 79 trans am with a olds 403 that has just been rebuilt. i put the motor in and ever since then it knocks. it sounds similar to a rod knock but I've been driving it so much that something would of happened to it. i was almost thinking its a torque converter or a flex plate. Ive had a stethoscope on it and its loudest on the bellhousing. but at low idle only you can hear it. and a friend of mine brought up an interesting point i hadn't thought of. it might be a defective lifter once the oil pressure rises its quiet. and when i really get on the throttle i can hear a little lifter rattle. What would everyone's opinion be? And I know its a gm lol. Thanks

[64dartgt]

Unfortunately I picked up a know too, but it is on a high mileage engine.  Since it happened after the tranny was rebuilt I was hoping it was the torque converter too, but from what I understand that should only happen if the car isn't in gear / at low rpm.  Anyway, it was twenty minutes work for the shop to throw it on a lift and check the bolts.  No dice.  The noise on mine increases as the oil thins out and is a steady thump from the lower passenger side.  Likely a bad rod bearing in my case.

[lee2]

Unfortunately I picked up a know too, but it is on a high mileage engine.  Since it happened after the tranny was rebuilt I was hoping it was the torque converter too, but from what I understand that should only happen if the car isn't in gear / at low rpm.  Anyway, it was twenty minutes work for the shop to throw it on a lift and check the bolts.  No dice.  The noise on mine increases as the oil thins out and is a steady thump from the lower passenger side.  Likely a bad rod bearing in my case.

thats exactly where my sound is comming from.

[Kern Dog]

There was a Dodge charger Trans Am edition?   

[RallyeMike]

It's pretty much impossible to tell over the internet. But here is a self diagnostic tool for Olds engines:

1. Get a set of earplugs.
2. Start the car up.
3. Pull it outside the garage onto the driveway.
4. Place a large brick on the accelerator pedal.
5. In a few minutes the source of the knock will reveal itself.

[lee2]

It's pretty much impossible to tell over the internet. But here is a self diagnostic tool for Olds engines:

1. Get a set of earplugs.
2. Start the car up.
3. Pull it outside the garage onto the driveway.
4. Place a large brick on the accelerator pedal.
5. In a few minutes the source of the knock will reveal itself.

I am about ready to do just that.