- Dec 12, 2011
- 4,656
Well just when I'm ready to turn 200K, I'm hearing this knock or tap..whatever. I started hearing it before my last oil change, wasn't terrible but seemed to go away above idle. I have had a cold start tick every once in awhile and I was starting to think of a weak oil pump, I have a gauge set and just looking right now to figure out how to get the adapter and someone has pointed me to a possible lead but I will get to that hopefully this week.
I never really had an issue with piston slap, at least I never really heard it. Problem is I also have an exhaust leak at #6 due to a broken bolt but I don't think this is an exhaust noise...however with this motor anything is possible.
The knock is at roughly 4-5 times per second, which is about 300 RPM at idle. I have pulled each coil and also the subsequent coil in the firing sequence, no change in pitch. I even disconnected 3 CYL at a time and no change in pitch. I really want it to be a weak lash adjuster but it's hard to pinpoint. I hear it near the valve cover and almost sounds "plasticky" for lack of better terms. The sound seems to come from where the head meets the block but could be traveling everywhere.
Could be a worn piston skirt but the last oil filter and this oil filter I had cut open and there's barely anything in the filter....no specs of gold, no metal that I can tell...just some small bits of black grit deep in the pleats.
I have a video and wanted a hot engine clip but my battery died on the camcorder but when hot the noise is faint. I will know more when I get a oil gauge hooked up but when I used a stethoscope around #4&5 it sounded like an xylophone. This could very well be the noise and sounds dull on the outside but inside through the scope it sounds just like an xylophone and whether or not that's the knock I'm hearing I don't know and could very well be a work skirt.
The thrills begin.
[video=youtube;Q3vIeIjtMXU]https://www.youtube.com/watch?v=Q3vIeIjtMXU[/video]
I never really had an issue with piston slap, at least I never really heard it. Problem is I also have an exhaust leak at #6 due to a broken bolt but I don't think this is an exhaust noise...however with this motor anything is possible.
The knock is at roughly 4-5 times per second, which is about 300 RPM at idle. I have pulled each coil and also the subsequent coil in the firing sequence, no change in pitch. I even disconnected 3 CYL at a time and no change in pitch. I really want it to be a weak lash adjuster but it's hard to pinpoint. I hear it near the valve cover and almost sounds "plasticky" for lack of better terms. The sound seems to come from where the head meets the block but could be traveling everywhere.
Could be a worn piston skirt but the last oil filter and this oil filter I had cut open and there's barely anything in the filter....no specs of gold, no metal that I can tell...just some small bits of black grit deep in the pleats.
I have a video and wanted a hot engine clip but my battery died on the camcorder but when hot the noise is faint. I will know more when I get a oil gauge hooked up but when I used a stethoscope around #4&5 it sounded like an xylophone. This could very well be the noise and sounds dull on the outside but inside through the scope it sounds just like an xylophone and whether or not that's the knock I'm hearing I don't know and could very well be a work skirt.
The thrills begin.
[video=youtube;Q3vIeIjtMXU]https://www.youtube.com/watch?v=Q3vIeIjtMXU[/video]