Engine noise

JFromm
JFromm Senior Contributor
I am hearing a knock in my Hornet engine. At idle which I think is a bit too high, I don't seem to hear it. When I put my foot on brake and put it in gear, it is really noticeable. Doesn't seem to get louder when I drive the car. Any ideas on what the problem might be?
Thanks,
John 

Comments

  • Geoff
    Geoff Senior Contributor
    John, it's really difficult to diagnose a "knock" online.   Can you hear it only when  in gear as you describe?   Does it worsen when cruising at light throttle?  Or increase when accelerating?   Is it rattle, a thump, a hollow knock, or a tapping sound?  More info needed!
  • Glowplug
    Glowplug Expert Adviser
    edited June 2018
    If you use a “ mechanics stethoscope” ie broom stick or piece of dowel to probe the areas around the engine and the transmission. One end dowel on the engine/transmission position other end at your ear.  Record your findings in or out of gear and different rpms. The results can help isolate and locate the source of noise.  Look closely at the engine and transmission while running as there maybe broken mounts allowing the engine/transmission to hit the body
  • JFromm
    JFromm Senior Contributor
    Used a broom stick and it appears to be at the bottom of engine. Can hear the noise  and it appears to be more prominent when I put stick on bell housing and oil pan. The noise appears to be a knock, buy does not get louder on acceleration.
  • Glowplug
    Glowplug Expert Adviser
    Check the same area with someone putting the transmission into and out of gear. If standard, push clutch pedal in and out as well as putting trans in and out of gear. Obviously have the brake set. One thing you did not say; does the knock remain steady cadence.
  • JFromm
    JFromm Senior Contributor
    Knock is steady
  • you can pull each spark wire off to see which cylinder it is coming from
  • Glowplug
    Glowplug Expert Adviser
    John, a knock that stays steady with or without load can be attributed to broken engine/transmission mounts, failed linkage bushings, flywheel bushing, throwout bearing etc. Bearing failure within engine usually will have changing sound cadence .
  • JFromm
    JFromm Senior Contributor
    Thanks for the input.