Engine rattle help me diagnose

[tbird187]

Hey guys trying to figure out the noise my engine is making.. It sounds like a rattle/knock but only at around 2k or under partial throttle goes away at WOT i might have to take a video of it to help describe it better... any ideas?

 

[95Vert383AOD]

You check the Heat shield on the Catalytic converter??? If the exhaust is stock they're known for this.

 

[tbird187]

offroad h pipe its def comming from the engine "i think"

 

[95Vert383AOD]

Check Rockers... You may have a loose one. If not that maybe the water pump?

Oh yeah if you have smog equipment a bad smog pump can make those sounds too.

 

[tbird187]

would a rod knock sound like this or would i hear it all the time? what about wrist pins I will pull the valve covers tomorrow and check it out

 

[95Vert383AOD]

I would think a rod knock would def. be there all the time. I have had a loose rocker do this before. The sound is light....and the more you drive and the looser it gets...the louder it gets.

 

[tbird187]

lets hope thats it!!! its def gettin louder over time.. what is the torque specs on those? 25 ft lbs? thanks for the help

 

[95Vert383AOD]

Not really sure. Are they stud rockers??? or the factory ones? Ive actually only had experience adjusting shaft rockers. Kinda skipped the whole pedestal/ stud rocker stage.


But correctly adjusted the rocker should be just loose enough to spin the push rod. when its at zero lift. Is it a chatter from the top of the motor???

 

[tbird187]

they are stock

 

[95Vert383AOD]

they are stock

Well listen close to the valve covers and give it a few revs from under the throttle body and look for the sound. See if the sound is coming from the left, right or front. Give it a rev from under the hood.

 

[gbranton]

I would think a rod knock would def. be there all the time.

I have heard a number of engines with a bottom end knock that goes away above idle speed as the oil pressure goes up, but not one that only knocks at 2,000 rpm.

Is it an automatic? I have heard cracked flexplates make a knocking noise that sounds like it's coming from the engine.