Engine Knock Noise

[klgray]

Hi All

My engine developed a noise yesterday - a knocking noise - maybe like a lifter going bad. It comes on when the car is cold or warm, and changes speed with the engine RPM. My alternator has been going bad (I think - see my previous post regarding the battery light and warning buzzer), but the sound doesn't come from the alternator.

Any ideas what it might be or how to diagnose?

Thanks!

 

[TimAT]

I take it that it's a light tinny sounding knock? Not a deep noise?

The tinny sounding noise you can take a heater hose or a long screwdriver and pretty well pinpoint by working your way down the rocker covers and listening to the other end. If it's a deep knocking, pull the spark plug wires off one at a time- the noise will change when you find the bad one.

 

[Sensei]

Get a mechanic's stethoscope at an auto prts store (about $15). This should help pinpoint the problem. If it is a deep knock, it may be the fuel pump rod.

God bless, Sensei

 

[klgray]

Noise Quieted a little / pinpointed it

Hi All

As I drove my vette home, the noise quieted. Now you have to listen fairly hard to hear it. I used the old hose trick to listen on the rocker panels, it sounds like its coming from the back right cylinder, right under the rocker panel.

A lifter going bad? Or an oiler issue?

Thanks for any further advice!