Vibration when stopped at light.

Discussion in '1970 - 1973 Specific' started by john Gialanella, Mar 21, 2020.

  1. autobahn

    autobahn New Member

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    I'm in the exhaust category
     
  2. Rosster

    Rosster New Member

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    In my younger days (mid 70s) that’s all we had!
     
  3. GMChevyOnly

    GMChevyOnly New Member

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    I use Bosch Platinum +4 spark plugs, I can feel the difference. Tried NGK Platinums and Iridiums but my SBC 350 runs best with the +4s.
     
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  4. john Gialanella

    john Gialanella Veteran Member

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    I took the SS 396 out today for 20 mile run. When it started to make noise I gave it gas and it went away, same as when I put it in neutral. I checked under the car from the side and the two mufflers had about a 1/2 inch clearance from the floor pan. In warmer weather I will go under the Camaro (I am getting to old for that) and see if a hanger is broken. Camaro has headers on it (I have the correct BB exhaust manifolds) I will check to make sure the bolts are all tight. As for the torque converter wouldn't it also cause vibration when I am on the Highway. I have no vibration on highway.
    John.
     
  5. ULTM8Z

    ULTM8Z Veteran Member

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    I think some part of the exhaust system is hitting resonance like I was saying in an earlier post.

    Is this something new? Could be a hanger is broken, so the stiffness of the system changed and now the resonant frequency of the system is in band with with the engine at that rpm.
     
  6. cuckoodawg3132

    cuckoodawg3132 New Member

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    I had a 76 type LT with a 350 and I had a vibration that drove me nuts, come to find out it was one of the exhaust pipe hangers. Just give a little tug on all exhaust components and see if anything is not secured.
     
  7. wnmech

    wnmech Veteran Member

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    You mentioned in post #24 about checking under the car and having a half inch clearance in neutral you really probably need to pit the car on 4 jack stands and put car into gear and see if the exhaust system shifts just enough to cause the rubbing vibration. Could be a worn motor mount shifting the engine just enough to cause what you are feeling.
     
  8. jbloake

    jbloake Veteran Member

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    John in post one from what I understand you shift to park and the vibration goes away. That’s telling me the fluid pressure on the vanes changed , causing the vibration to stop. Same when on rolling along under light load you are getting the vibration, then load up the pressure it goes away , From post 24 it seams to be more of a noise than a vibration . Somebody else must be an trans guy that would know better. It just sounds like torque shudder to me .
     
  9. john Gialanella

    john Gialanella Veteran Member

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    In warmer weather I will check hangers on mufflers. Also I have been meaning to take Camaro to Transmission place to replace trans fluid. I can ask about Torque converter. But I am concerned that guy can say that that is what it is (when it is not) to make money. I will search on internet for problems caused with bad torque converter.
    John.
     

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