Rattle sound

[Huicho417]

I recently installed the exhaust system in my car and now I can perceive every little sound. It sounded great when I left the shop. Halfway home I began to hear a rattle sound. It was louder when I pulled into my driveway and sounds like it’s coming from under the engine. I left the car running and crept underneath the car and sounds like it is coming from the engine-transmission mating area. Today I took off the transmission cover plate and noticed the flex plate had some scratches and seems like it’s slightly bent. I had a little trouble when placing the engine back into the car and it’s possible that I may have bent it. Is it possible this is the rattle I hear? The flexplate rubbing against something because it is warped minimally? Thanks in advance.

 

[pnora]

Usually if bent you would notice something odd bolting the converter up. I would check all the bolts and paint the marked areas. Run it and see if it returns. If it does I would check the crankshaft end play.

 

[Lefty71]

It's a job I know, but it sure looks like you ruined that flex plate.... They are cheap, I'd get it out of there if I were you. HTH, Lefty71

 

[pnora]

You cant tell by the pictures if it is bent at least I cant. Tell tale sign of being bent would be one of two things. One when the converter was pulled up you would see an obvious differences in the space between the flex plate and converter lug. Two if bent the bolt holes might not line up. If he had those problems I would agree. On a small block the most common problem is the tin shield rubbing. As I said check all the bolts, paint the suspect areas and run it without the shield.

 

[Huicho417]

When I run my finger over the scratched area I can feel it is bent. I just can’t figure out what it would rub against to create the rattle. I also found an older picture that shows when I lowered the engine on the hoist I put pressure on it against the support blocks

 

[pnora]

When I run my finger over the scratched area I can feel it is bent. I just can’t figure out what it would rub against to create the rattle. I also found an older picture that shows when I lowered the engine on the hoist I put pressure on it against the support blocks

View attachment 1104362

Verify where it is hitting. It is that simple. If you do not want to do anything on the suggestions than pull it and put a new one in.

 

[Huicho417]

Thank you I agree on replacing it with a new one. I was planning on changing the seals on the transmission because it is leaking at the moment. I am going to take this opportunity to clean it, reseal it and also change the mount.

 

[Dave6T4]

I was going to say that if you continue to run with a bent flex plate, you will take out the torque converter seal, but it seems like you are already there. Check your oil pump bushing and torque converter neck for wear as well. I always check used flex plates by placing them face down on flat garage floor to see if amounting surfaces are flat.