I have a chevy 4.3L v6 262ci engine from a 1985 astro van in my jeep
cj5, installed by a previous owner. Engine runs great, but has
recently developed a clatter/choppy sound resonating from the right
side. I've tried adjusting the timing (perhaps it's pinging), but no
change. Engine seems to have full power. It seems to become worse
once the engine is warmed up. Upping the RPM's sometimes makes it
stop, but when it comes back down it starts again. I can hear it at
800-900 RPM's when idling, and around 1500-1800 RPM when cruising.
When I adjust the RPM's, while under the hood, I can make the sounds
come and go.

At first I thought it was my distributor rotor. When I took the top
off, the rotor wasn't even bolted down. I secured it, thinking that
would do the trick, but no luck.

Obviously, I am no expert, just a weekend mechanic. Does anyone have
any ideas? Thanks a lot.

Paul Theisen

Listen to where the sound is coming from a bit closer.
You mention right side. See if it gets louder if you put your head near the
tire on that side.
If so, then it is probably the exhaust leaking.



"prtheisen" <prtheisen@gmail.com> wrote in message
news:2064dd9e-fb57-40de-93ca-720a785fbd0a@d42g2000prb.googlegroups.com...
>I have a chevy 4.3L v6 262ci engine from a 1985 astro van in my jeep
> cj5, installed by a previous owner. Engine runs great, but has
> recently developed a clatter/choppy sound resonating from the right
> side. I've tried adjusting the timing (perhaps it's pinging), but no
> change. Engine seems to have full power. It seems to become worse
> once the engine is warmed up. Upping the RPM's sometimes makes it
> stop, but when it comes back down it starts again. I can hear it at
> 800-900 RPM's when idling, and around 1500-1800 RPM when cruising.
> When I adjust the RPM's, while under the hood, I can make the sounds
> come and go.
>
> At first I thought it was my distributor rotor. When I took the top
> off, the rotor wasn't even bolted down. I secured it, thinking that
> would do the trick, but no luck.
>
> Obviously, I am no expert, just a weekend mechanic. Does anyone have
> any ideas? Thanks a lot.
>
> Paul Theisen

On Sun, 9 Nov 2008 11:54:02 -0800 (PST), prtheisen
<prtheisen@gmail.com> wrote:

>I
>Obviously, I am no expert, just a weekend mechanic. Does anyone have
>any ideas? Thanks a lot.
>
>Paul Theisen


Maybe this??

http://wiki.answers.com/Q/What_does_a_knock_sensor_do