My 2000 monte carlo recently started having a rattling or knocking noise . It does not do it when i first crank it after it warms up . i pulled the front valve cover off crank it up sound like it was coming from the valves i noticed that the oil was not spurting out the end out the push rods change the oil pump still rattling could it be the knock sensor?

 

Did you also change the timing chain when you replaced the oil pump? I had a Series I 3800 in my Oldsmobile that had a stretched chain and would cause a rattle at startup along with excessive valve lash on the rockers. Did you also check the valve lash? If you didn't, that might be another thing to check.

 

Was there any oil at all getting up to the head? What was the oil pressure before? What did you find when you removed the oil pump? What is your oil pressure now? Is it getting oil into the heads now?

It'll be extremely hard for us to diagnose a noise remotely, but if it had so little oil making it up top that you went through all the effort to replace the pump, then that is concerning. If the sound seems like its coming from up top, I wonder if it's a lifter collapsing from lack of pressure?


The knock sensor is just an electrical receiver that's physically threaded into the block. Its not possible its making any kind of noise.