What could cause roller rockers to not touch cam?

samuel79samuel79 Member Posts: 8
edited February 2016 in Saturn
I have a 2003 Saturn vue. It had a timing chain guide break. And all the roller rockers came off the valves. After replacing the guid and resetting the timing the roller rockers aren't touching the cam. Any idea in what could be causing this?

Answers

  • thecardoc3thecardoc3 Member Posts: 5,479
    The valves might be bent.
  • samuel79samuel79 Member Posts: 8
    That's what I was thinking
  • samuel79samuel79 Member Posts: 8
    Is it possible to bend all 16
  • thecardoc3thecardoc3 Member Posts: 5,479
    Yes.
  • samuel79samuel79 Member Posts: 8
    Is there a chance it could be something else
  • thecardoc3thecardoc3 Member Posts: 5,479
    edited February 2016
    If I could find a spec for the valve spring installed height, you would be able to measure them and know if the valves are in fact bent but its not listed in regular service information. You could just measure them all right now, they should be within .050" (fifty thousandths of an inch) of each other. So the next best test is to either use a bore scope and take a look at the valves, or perform a cylinder leakage test using regulated shop air pressure.

    It's highly unlikely that there is something else at play here. Even if this was the result of all of the lifters collapsing, they don't have enough internal travel to not have the cams applying some of the valves at any one position. Even then the lifters are spring loaded and they should be fully extended when released. How much space is there between the roller and the cam?
  • samuel79samuel79 Member Posts: 8
    Maybe a big eighth of an inch. All springs are at the same height

  • samuel79samuel79 Member Posts: 8
    Going to do an oil pressure test and compression test in a few min 

  • samuel79samuel79 Member Posts: 8
    Have 0 on compression test all cylinders

  • samuel79samuel79 Member Posts: 8
    Does car need to be running to check compression
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    Not if you do a cylinder leakdown test, one at a time. You'd have to make sure your valve timing is correct though, and that each cylinder in turn is at TDC.

  • thecardoc3thecardoc3 Member Posts: 5,479
    samuel79 said:

    Maybe a big eighth of an inch. All springs are at the same height


    An eighth of an inch is .125, you should be less than .050 variance. Combine that with no compression and you have your answer.

  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    Doc, any chance pedestal bolts could be loose from sudden shock?
  • thecardoc3thecardoc3 Member Posts: 5,479
    No. This engine doesn't use those.
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