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      12-23-2020, 11:45 PM   #1
Bubbles
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Rod knock sound pretender

Background: BE bearings in for 5k and while I idled in line at the gas station a sound that no S65 owners wants to hear started.



Although the oil analysis came back clean at 3k, I had this sinking feeling that something went sideways with the bearing job.

Sent the video to a buddy and he reluctantly agreed it may be rod knock.

I figured if I made it back home, I’d throw it on the lift to see if I could get lucky and it be anything but rod knock.
Initially, I thought it was the exhaust shield on the drivers side that hung a bit too loose for me. Nope.
Power steering line was close to the turner skid plate, adjusted the line. Nope.

Brake wear sensor zip tie broke allowing it to hit the control arm. New zip line attached. Sound remained. O2 sensors were set cleanly. No exhaust leak.

Last attempt I found the culprit. The vibra tech engine mount on the driver side top nut was not tight, the passenger side was not at the torque specs but not a loose as the drivers side. Note the top nut for the engine mount is a nylon nut (I think it came with the mounts) so either it backed out over time or I didn’t get the torque right on install. I probably should have started with the mounts.

Hopefully this helps someone.

After the fix
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Last edited by Bubbles; 12-24-2020 at 09:00 AM..
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