"Timing Rattle" with Tone Ring Mod?

[Buffalo]

I have an '03, HO that I have done the Tone Ring Mod, to. Also, have Air & Exhaust mods & a Van Aaken C-3. 2 (duration, only) box.



On cold starts & until it starts warming-up, I notice a strong rattling sound, like earlier generation engines, at low rpm's. I've returned the TR back to its stock setting & it goes away, mostly.



Does this sound like "timing rattle"? If it is, is it doing any damage? Would it be better for the engine to "back-off" the timing, a bit?



I don't mind the added sound but, if it is potentially doing damage, I'll back it off.



Thanks for your help.



Joe F. (Buffalo)

 

[JHMiller]

Joe, I did the sensor

At first the truck seemed smooth and quiet and more responsive. Within a week it was rattling like crazy, hate that sound. I backed the sensor off 1/2 degree, thought it helped a little on the test run and decided to leave it there. Now a week later, it's quiet and I mean noticably seems to be running great, I don't get it, a noticable performance change after a time lag. ??

Anyway the full advance of the sensor seemed to be more than my truck liked, I plan on dinkin with it some more in the future to see if a fine tune setting can be had but at least I've lost that pot metal hammering sound.

 

[Scrappy]

Mine does this too (even with the TST off) I backed mine off 1/2 way and still does it, but I like the mileage so I have left it Half way advanced.

 

[Matt400]

I did my sons 03 CA SO and it rattles more with the advance but only on throttle tip in. Once moving it won't do it and its also quiet when warmed up. I did about 3 degrees.

Doesn't seem to help with throttle response.



I did the same 3 degrees on my 05, super quiet and noticeable throttle response improvement + 1. 5 better mpg's.

Just a guess on theory but the 03's ecm may have been programmed for more timing advance during cold engine start ups, possibly even more advance even when warm so the added 3 degrees gets noticeable noise.



The continued strive for lower NoX levels on newer models may have required less advance in the ecm programming so the 3 degrees is more welcome on the 05.



On the other hand the 05 in stock trim is more quiet at idle than the 03 in stock trim so the pilot shot probably differs also. I may move the 03's back to where it was cuz it doesn't seem to help like it does on the 05.