View Full Version : Knocking Noise From Engine
Kracka
05-06-2004, 09:24 PM
What can cause rod-knock? My car makes a bad knocking noise from the engine under load and when reved to about 2k rpm in neutral. No noise at idle. Any other theories on what it could be?
A//// Guy
05-06-2004, 09:38 PM
Check timing. I got knocking noise after I realized the TB had skipped a couple teeth. That happens apon startup when the engine has that increased load right away... or atleast that was my reasoning why it kept getting worse everytime I started it.
Are you logging? Because the first thing I noticed when it started was lots of knock when you approached boost at all. I mean when it got bad I couldnt even get close to 0 vacuum the knocking was soo loud.
At fisrt I thought it was bad gas until I heard the audible knocking start. Just a thought...
I dont know anything about rod knock so...
npaulseth
05-06-2004, 09:57 PM
How's your oil been? Does your car burn a significant amount of oil? My car has a spun bearing, and it was very very audible. Although mine knocked at idle, realy bad. Was your engine ever rebuilt?
JasonR
05-06-2004, 11:22 PM
Rod-knock can be many things or theories. Rod-knock and knocking 2 different things. Although if knock sensor not working, dentonation can cause rod knock or blow engine. Rod-knock mechanically can be caused by flywheel cracked or contacting splash shield, loose or broken balancer or bore clearance, bent connecting rod, piston 180 degrees off, loose tourque converter bolts, excessive main bearing, rod bearing, crankshaft end play clearance, improper oil viscosity, hydrolic lifter bleed down. Sounds like mild to severe knock occuring when accelerating so you get sharp metallic sound when throttle opening. I rod-knocked my first race engine 3 years ago and first two blocks I drove car. I was so excited to run car hard and had afc at time. I richened wot and raced down block of street. That is why I dyno tune seriously now and get a/f mixture perfect. I have wideband o2 sensor in car and use wideband on dyno. Only thing you can do is use engine until it fails, unless you want to take apart and have professional correct mechaniclly your problem. Either way going to cost you money.
vBulletin® v3.8.4, Copyright ©2000-2025, Jelsoft Enterprises Ltd.