1st Gen R53 Cooper S Help: grinding noise when accelerating hard....

Discussion in '1st Generation: 2002–06 R50, R53 & 2004–08 R52' started by CheckersSD, Mar 15, 2011.

  1. CheckersSD

    CheckersSD New Member

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    I don't know. The sign says dynojet.


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  2. CheckersSD

    CheckersSD New Member

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    While my car was up on the lift there were marks on the bottom of the cat as well as the top of the x-brace. Even though there is about an 1/8" clearance, the vibration from the exhaust is definitely contacting the x-brace. Even with the new bushings and new upper motor mount, during hard acceleration there is still vibration. I am going to buy some washers or spacers and place them between the x-brace and the frame. Or I might take a dremel to shave off some trimming on the brace or cat to make extra room. I will update as I move along with this project.
     
  3. CheckersSD

    CheckersSD New Member

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    Here are some pics of the old motor mount. You can also see where the fluid splattered on the side of the engine.

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    [ame=http://www.youtube.com/watch?v=IiTr99OJ4EA]YouTube - IMG_1123.MOV[/ame]

    I am glad the engine mount has been replaced. Now I need to clean the engine bay. Any suggestions?
     
  4. mini_racer

    mini_racer Well-Known Member

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    #64 mini_racer, Mar 26, 2011
    Last edited: Mar 26, 2011
    If you only have 1/8" clearance that just is not enough.

    Make sure that forward catback mount is supporting the exhaust properly.

    As mentioned earlier you can add a small spacer on the rearward mounting points of the X_brace, and even grind away a small portion of the X-brace exactly where the exhaust is touching to no ill effect.

    I would personally not grind-on or beat-on the cat itself. the core of the cat it very brittle and you could easily break it up with a little trauma. You could also grind through the thin walls or introduce a weak point that will fail sometime in the future.

    Good Luck and congrats on the new power.

    Oh and common Isopropyl Alcohol is the perfect solvent for the old dried on motor mount hydraulic fluid. Strong enough to dissolve this stuff, yet not so strong it will harm any paint or dry out any rubber it may contact. You still will need some agitation though, a small plastic bristled brush on the rough surfaces and any rag or even a paper towel wet with the alcohol on smooth surfaces will do the trick.
     
  5. Metalman

    Metalman Well-Known Member
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    Yeah, what mini_racer said.....
    And don't rub too hard on the body paint inside the engine compartment, as it doesn't have the protective clear coat and tends to come off easily.
     
  6. Crashton

    Crashton Club Coordinator

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    Yes like has been said don't wail on the cat with a hammer. You will breakup the inside. Best clearance that ill-fitting X brace thing. Use the hammer on the old engine mount. ;)
     
  7. CheckersSD

    CheckersSD New Member

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    Definitely will keep the hammer away from the cat. What size spacers? Should I use metal washers or rubber type bushings?


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  8. Crashton

    Crashton Club Coordinator

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    I'd use metal ones. Rubber ones will crush when you tighten things back up.
     
  9. mini_racer

    mini_racer Well-Known Member

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    #69 mini_racer, Mar 27, 2011
    Last edited: Mar 28, 2011
    Absolutely right........... only metal, if you use rubber you will defeat the chassis stiffening effect of the X-brace.
    So, use metal and I would not go thicker than the thickness of the X-brace mounting tab, and roughly the same (X,Y) dimension as you do not want to compromise the value of the X-brace. This is one of those smaller things to try so you will be real lucky if this completely remedies the issue. The good thing is that this is easy to try as you do not have to touch the front mounting bolts, just remove the rear bolts and slip in your spacers/ thick washers/ etc. and reinstall the rear bolts. If still not enough clearance than drop it and start grinding.

    Hey, did I mention that front most support on the catback? Verify it is doing it's job. :^)
     
  10. CheckersSD

    CheckersSD New Member

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    Perfect. How much clearance is acceptable for the space between the xbrace and cat, like 1/2" or 3/4"?
     
  11. mini_racer

    mini_racer Well-Known Member

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    My view is if you go this thick:
    1. You will need to get longer bolts.
    2. You will compromise the effectiveness of the X-brace chassis stiffening.
    3. You will significantly reduce your rode clearance and hit it much more more often.

    To me, 1/4" would be the absolute max extreme on the spacers. Of course........YMMV.
     
  12. CheckersSD

    CheckersSD New Member

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    Makes sense. The contact point on the x-brace is on the solid bar portion. I think the spacers will work fine. Thanks.
     
  13. CheckersSD

    CheckersSD New Member

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    Just want to let everyone know I fixed it. Bought washers at lowes, and added 1/8" to both sides of the rear xbrace. Noise is gone!
     
  14. Mr. Jim

    Mr. Jim Mudshark
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    Sweet :Thumbsup:
     
  15. Crashton

    Crashton Club Coordinator

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    That was easy! Glad you worked it out.
     
  16. mini_racer

    mini_racer Well-Known Member

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    Congrats on the fix!
     

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