# Engine running rough - making horrible noise (metal pang/light tap on deceleration)



## sterlingstone (Jul 1, 2009)

Hi,

I have a 1986 Nissan 720 King Cab Pickup with a 2.4 Litre Naps - Z carburetor based engine. Just yesterday it made a real weird loud panging noise (Kind of metal and thumping (light) together that was noticeable on deceleration.

Please help me figure out what is wrong. Seems to have spark to all plugs, no apparent vacuum leaks (by spraying carburetor cleaner on carburetor, intake manifold and all apparent vacuum lines there is no change in rpm.)

The engine is extremely rough running and vibrates heavily at idle. It improves a bit around 1800 RPM but something is wrong. The load tapping noise on deceleration scares me. I have made no changes to timing for the past year or two.

What could be wrong?


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## Nickin (Nov 11, 2009)

*Intersted in the solution*

I have the exact same issue. Did you get it resolved?


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## pulsar86 (Aug 13, 2009)

Valve related maybe? Remove the valve cover and check for any broken valve gear. Broken rocker arms etc.


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