Rocker fell off valve? What can cause this?

Discussion in '96-04 - 4V Specific' started by dbaird, Apr 1, 2015.

  1. dbaird

    dbaird New Member

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    Hi All I recently bought a 98 cobra and am trying to get it fixed up and first thing was the motor was making a knock sound in the head so I have removed the valve cover on the driver side and found this. Looks like the rocker has fallen off the valve and has started eating up the exhaust cam. Any idea what can cause this? The cylinder has oil leaking into it from the head but still has decent compression when tested. Im assuming I will have to pull the head but I wanted to see if anyone had ever seen this before and what needed to be repaired on the head.

    Thanks!

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  2. Burninriverdiver

    Burninriverdiver Well-Known Member

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    I'm no expert, but it looks like the valve is stuck open and most likely bent. That could cause the rocker to fall off and chew up the cam. That had to sound pretty rough! If that is the case, I'd replace the valve, rocker and camshaft at a minimum. Good luck with the tear down and rebuild... Keep us posted on your progress
     
  3. 96blak54

    96blak54 Legend

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    Im gonna say if the valve is bent, your guide is trashed too.
    An adjuster thats lost oil supply will bleed down allowing the rocker space to wiggle out. Low oil and hard driving will cavitate the oil pan especially hard cornering. This will limit the supply to adjusters. Also if the spring is broke in adjuster, a cold start up when the adjuster has been bled down will allow wiggle room
     
  4. dbaird

    dbaird New Member

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    If the valve was bent wouldn't the cylinder have 0 compression?? I did a compression test and this cylinder was the same as the others. Thats where i am confused. There is also plenty of oil running into the cylinder from the head somewhere on this cylinder.
     
  5. 96blak54

    96blak54 Legend

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    A 32v modular can drain the oil pan during hard runs. Hard cornering adds to the cavitation. Hard launches adds to the cavitation.

    Pull out the lasher and check it