73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: lifted87 on April 19, 2013, 12:52:15 pm

Title: Engine knock..
Post by: lifted87 on April 19, 2013, 12:52:15 pm
After searching the forum I didn't really find anything like my issue.... My stock 350 TBI has 110k on it and after sea foaming it I changed the plugs, wires, dist cap and oil. The truck knocks under a load but I cannot hear it while driving unless while slowing down the trans down shifts it will knock. It does seem to be rpm related as it knocks faster the higher the rpms... I recorded a video and hopefully you can hear what I'm talking about.

0:17 and 0:29-37 you can really hear it..
http://www.youtube.com/watch?v=NNlHqpLQTf4&feature=youtu.be
Title: Re: Engine knock..
Post by: bd on April 19, 2013, 08:42:00 pm
Sounds like a rod.   :(
Title: Re: Engine knock..
Post by: Irish_Alley on April 20, 2013, 07:06:20 am
was it knocking before you changed the cap and rotor? or is the knock the reason you changed and sea foamed
Title: Re: Engine knock..
Post by: lifted87 on April 20, 2013, 09:38:38 am
No it wasn't knocking before. I'm going to play with the timing and hopefully its a timing issue causing the knock.
Title: Re: Engine knock..
Post by: Irish_Alley on April 20, 2013, 09:57:44 am
yeah could be the distributor cap not seated right or its too far advance that would be the first thing i check. if it knocks under a load its points straight to timing
Title: Re: Engine knock..
Post by: lifted87 on April 22, 2013, 04:12:42 pm
Quick update.... I was watching my oil pressure gauge and as it would fluctuate the knock would get worse. I was coming home from the gym yesterday and it pegged 0 psi as i was turning into my neighborhood and it was knocking like crazy so I thought well that's the end of that motor. Today I swung by advanced auto and bought a new oil pump for $22 bucks and thought what the heck might as well try it. Sure enough fired it up, knock, knock, knock, gauge pegged 30 and silence ever since!   So a 22 dollar pump, 15 dollars in oil and 10 bucks for a new pan gasket and so far so good.