Sounds like a timing problem, carbon deposits or cheap gas. Run a tank of
premium through it and see if the problem goes away. If it does then you
know you have pinging. The Brits call it "pinking".

Cheers,

Earle

"Slim" <slim@pickins.com> wrote in message
news:463b5420$0$15179$4c368faf@roadrunner.com...
>
> 1996 Civic DX Coupe 77K
>
> I have noticed a knocking noise from the engine at 35-40 mph.
>
> No loss of power or gas mileage, just a strange
> "chugga-chugga-nok-nok-nok" at 35-40 mph. Its not very loud, but
> notciable.
>
> Any guesses? Clogged injectors?
>
> Last major service was at 60K (rotor/distcap/plugs/wires..etc)
>
> Any help appreciated.
>
> Thank you all.
>
> -Slim
>