What would cause what sounds/seems like backfireing in the exhaust at high rpms (4k range)? It's the best my Dad and I can figure my truck which is a NBS 99 Silverado
Adair
Is the sound occurring while setting still or while moving?
Never tried revving it that high just sitting there.. this always happend when moving... and normally it takes a second for it to start... eg, after the tranny down shifts and it's good and locked in..
Adair
You have checked ALL the U Joints correct? (4x4 check the front axles also) Try it through the gears manually and see if it occurs at the same RPM ( that will tell you if it is engine/converter related) If not then it is probably in the driveline.
have you changed your fuel filter lately
It was changed not to long ago... can't remember but i have it wrote down, less then 10k ago and it was doing this before.
Adair
btw, why?
Adair
wrong as in how? just flat out the wrong type/brand of spark plug? please do expound. because I do need to do plugs and wires. Adair
I've seen this happen on a truck that some &$^% put champion plugs in. Make sure your GM truck has A/C delco plugs of the correct type.
Very true... The only things I'll ever use Champion spark plugs for are my lawn mower or outboard motor.
For the older, pre-platinum spark plug engines, I always use the plain ol' black base AC plugs. If it originally had platinums in it, then use AC platinums. The'll last forever.
Tony
I have AC platinums in it now but they are old but not real worn.. i just want to change them so i know when they have been done.. Arn't there several versions of the AC Delco Platinum plugs? What works best for my 99 5.3?
Adair
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