My mostly stock 12 Ultra Classic has a strange new noise. It has stock air intake, stock header with cat removed + Xied, and stock CVO SE mufflers. When the bike is at hot idle and I “blip” (rapid open) the throttle, I heard a strange single metallic crack or pop before the engine revs. The sounds reminds me of a metal on metal impact. Kind of like whacking your frame with a large screw driver or something similar. A couple of times it backfired after I did this. I installed the Xied right after I installed the cat-less header and it seemed to be running fine with no noticeable backfiring or decal popping.

Could this be a single loud ping of detonation? A crack of that sounds like metal on metal is a bit concerning. It only happens when I blip the throttle rapidly from a hot idle and it’s always a single crack or pop at the beginning.

Any ideas about what it might be?

Thanks

 

If it's not ping, and it could be, I would suspect the comp going south...

 

Keep listening till there's no mistake it's a ping then get back on here and we can help you from there, otherwise it's really tough to diagnose from where we are sitting. One thing for sure, if it's a ping it will get worse...believe me I know all about it and can help, so can a host of others.

 

Don't blip the throttle. Problem solved.

 

Ping is definitely a common issue. A temporary band aid is to clean the carbon off the top of the pistons. The more serious issue is that oil consumption is the #1 cause of excessive carbon. A shot of octane booster in your next tank of fuel might tell the tale...

 

Forgot to mention mileage is only about 4K, so I'm not sure how much carbon build up there could be.

I'm familiar with what detonation sounds like, but that's usually a series of sounds. This is one single noise and louder than any detonation I've heard. I guess the smart thing to do would be to just take it to the shop since I'm still under warranty.

 

I'm still favoring a comp in its initial stages of failure. Your dealer will likely tell you it's 'normal'

 

I am starting to see a pattern. This is the third thread I have read with a weird noise on a 12 motor. All three threads are common to my issue...sound, milage and thoughts of source of noise. My motor is blown @ 4500miles. Mine started sounding like detonation under light accell, then sounds of a small ball pein hammer rapping on the rocker boxes under steady state of rpm 200miles later. Took it to a shop they could not duplicate. Changed oil noticed lots of metal. 200miles later it knocked once hot at idle to any rpm.

I hope this is not becomming a norm.

 

I first heard my current noise a couple of nights ago. I was riding home under normal conditions and I heard the loud single pop. It was so loud, I actually thought something had broken or fallen off the bike. I immediately pulled over and inspected the bike as best as I could in the dark. Then I turned around and retraced my path to find whatever came off.

That night I equated the sound to metal snapping. I really thought something had broken and didn't ride it again until I looked it over thoroughly. Today I heard the noise again as I pulled the bike in the garage after a long ride. I finally realized I could reproduce the sound consistently by blipping the throttle.

 

Almost to the t. I was interstate riding 500mile run to tje mntns. I thought I picked up a rock.

I suggest you do a good ride and pull your crank sensor or drop the oil and look for metal.