Discussion in 'Engine & Drivetrain' started by Daveed, May 12, 2018.
Any ideas? This seems to be fairly common....
Its definitely coming from the bottom end which isnt good,... but for some reason it doesnt sound like a rod nock,... almost sound like a broken oil pump, but you said oil pressure is good right ? maybe others will chime in.
it dont seem to have that rod knock sound really. could be a bad valve spring or lifter.
one side up top it should sound louder, pull that valve cover and see if any things busted looking. check the push rods for play, spin them to make sure they are not bent.
Oil pressures at 38 idle and goes up around 10 every 1000rpm.
Thank you, ill look into that
Another test you can try to determine weather its a valve/spring/lifter; Take a piece of paper,.. while the engine is idling, hold it over the tailpipe trying to seal the paper over the end of the pipe,.. you should only have pressure pushing paper away,.. if the paper is being sucked back into the pipe you may have a valve/lifter issue.
I tried this and it def only blew outwards. Im starting to think its something lose or broken om flywheel
Yours sounded like my 89 Sierra. It was the flex plate cracked causing that noise. Yours too sounded the noisiest right under the bellhousing
You can get under it and pull the inspection plate off the bell housing (it looks like a pop can bottom) and listen and look at the flexplate (flywheel).
This one either doesnt have an inspection plate or i can not find it...
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