motor knock?
 

Just bought a 2000 vette a month ago, thelast couple of days when I start it the motor knocks for a little bit then quits. Then sometimes it knocks while im driving it..Just wondering if any sensors would cause cause it to sound like its knocking or the bearings are shot.[:@] Thanks for the help.........

RE: motor knock?
 

Hi...Don't know of any sensors that would do that. I was going to say that you have a cold knock, but that usually goes away after the engine warms up. When your driving it, when do you hear the knock?? during acceleration, deceleration, or at a steady speed? Knocking or rattling at a steady speed could mean worn main bearings. I take it you have good oil pressure, check the oil level, make sure it's not over full, an indication that gasmay entering the crankcase somehow and thinning the oil. How many miles are on it? I have seen a cracked flywheel make one sound like the engine is knocking.

RE: motor knock?
 

Thanks for the reply rshiver. Sorry I meant to put this in the c5 section. You hear it slightly when accelerating and it has 62000 miles on it..Sorry again for putting this in the wrong section. Well if the bearings are wore, then I guess my best bet would be to put a crate motor in it..How much do the LS1 crate motors run? Thanks again for the help

Oil type?
 

You have probably already changed it but just in case...
Change the oil/filter in case the oil is shot or the wrong type.
You could also cut the filter open and inspect the pleats for signs of bearing material.
Bert

RE: Oil type?
 

Mine still has a knock. ('90 stock engine) I have had it tuned up , timing checked, vacuum checked, new
EGR valve installed, and used the octane booster but when you accellerate extra it still has what I am
going to describe as a valve clatter sound. Guess I'm going to have to live with it.

RE: Oil type?
 

Is it "pinging"? Could be bad gas or incorrect timming. Back home when I was a kid this one Sunoco filling station would put water in the under groung tanks to rip everyone off. If we ever bought gas there our cars would ping like crazy.Never could figure it out till my brother worked there and watched him do it.

RE: Oil type?
 

The LS1 motor sometimes has a tendancy to sound like lifter noise when you first start it & the engine is cold. Then as the engine warms, it goes away. But you say you here a knock later on while driving. I would check the timing if it sounds like a 'engine knock.' Then check wires and change gas.

RE: Oil type?
 

my LS1 did that in my 98 TA for a little while, but then it did it under acceleration...the oil pressure began dropping and I knew then that a rod bearing took a crap. I ended up buying a 2004 LS1-based 383 short block from LS1 Performance from Chandler, AZ. It cost me 3495, plus shipping, which was around 3-400 bucks.

Check your oil pressure and listen to when the noise occurs, but there's a good bet that a bearing is shot in the motor. I was able to drive it on short trips in town, keeping it under 2500 RPM from May to October withouta hitch...