any way to stop a motor from knocking?

[thezentree]

my 97 vortec 350 knocks, and i'd like it to stop. is there anything short of a rebuild that would help this out?

and almost as importantly, what exactly makes a motor knock? pinging is predetonation (correct me if im wrong), so what is knock?

 

[big83chevy4x4]

knock=rod knocking on the crank=needs new bearing.

you can just pull it apart and put new bearings and rings in it. northern sells a rering kit for this.

 

[bigburban383]

Higher octane fuel or boosters will prevent ignition knocking. A rebuild will stop the rotating assemble knocking.

 

[thezentree]

i switched to a higher octane fuel to stop pinging, since the local stealership doesnt know their ass from a hole in the ground and screwed something up. but i digress....

i'll take one new motor, please!

 

[TSGB]

No hijacking here, but I would also like to know what leads to the conditions that cause an engine to knock. Just lack of oil changes...? My 3.8 in my Cougar knocks more than a Jehovas Witness...


Damn furds.

 

[ntaj*ep]

There are many different kinds of knocks.
I have heard fuel pump pushrods knock in a SBC. The "new" generation Vortecs have piston slap that in some trucks are louder than diesels /forums/images/graemlins/eek.gif(a condition deemed normal by the general /forums/images/graemlins/shame.gif) Also a cracked flex plate can sound like a knock. To properly pin point a sound like a konck you would need to find the area/conditions when it will appear.
Usually a low pitched hollow sounding knock rythmic with engine RPM would indicate a rod possibly main bearing failure. But there are so many things that it can be its hard to say what caused it and how to fix it...

 

[thezentree]

[ QUOTE ]
No hijacking here, but I would also like to know what leads to the conditions that cause an engine to knock. Just lack of oil changes...? My 3.8 in my Cougar knocks more than a Jehovas Witness...


Damn furds.

[/ QUOTE ]

in my case, its probably water intrusion from the time i almost hydrolocked it /forums/images/graemlins/doah.gif

 

[Blue85]

[ QUOTE ]
any way to stop a motor from knocking?

[/ QUOTE ]

Turn it off? /forums/images/graemlins/dunno.gif





Sorry.

 

[TSGB]

So is there a way to hunt a knock down in an engine, and actually find out where it is without completely stripping it?
/forums/images/graemlins/confused.gif

 

[diesel4me]

You can use a mechanics stethoscope(looks like the doctors!)to help pinpoint the source of the noise,and by pulling the plug wires off one cylinder at a time it will usually deaden or reduce a rod or main bearing knock in that cylinder,wrist pin or piston noises usually get louder when the plug wires on that cylinder are pulled--be carful because the HEI ignition coil can put out up to 50,000 volts,use insulated pliers make for that purpose,or you'll get zapped for sure.Is your motor rapping(like a rod knock?)or is it just "pinging" like when you have cheap gas and overadvanced timing?. /forums/images/graemlins/crazy.gif

 

[thezentree]

well, it does both, but it doesnt ping hardly at all anymore because i run 89 octane fuel. im thinking that i got water in a rod bearing and warped it or something

 

[down4thakrown]

try any lucas??

 

[thezentree]

yea, it helped, and oil pressure is up about 10psi when at operating temps and idling, but its still knocking a little bit