i have a 04 mustang making a tapping sound i replace lifters but sound still present wat could it be

its a 3.8 L use the 5-20 valvoline oil

What kind of oil do you use, synthetic or petroleum, and what viscosity? 5/30, or what? And which engine?

regular oil i guess its petroleum 5w20 and the engine size its a 3.8 v6

That oil is good, so it's not too thick is why I asked, Now, did you put in hydraulic tappets (lifters)..I don't recall offhand what that engine uses. Synthetic oil is my personal preference, but that is all it is, personal preference it is not what is causing the sound. I'm full of questions, I know...but is it a little tick or more like a knock? Mileage? I don't even know if it's an OHC or has pushrods. A bent pushrod will do that.

its more like a knock it sound like it could be the lifters but its not cus i just replaced em it has 115 miles on it and its push rods

You may have to open her up again and roll the pushrods on a flat surface. No warping. But before you tear her apart maybe re torque the rocker arms rail nuts, If I remember they are on studs with a nut, as opposed to a bolt securing the rocker rail and do a compression test, Does it smoke out tailpipe?

no it dose not smoke also on idle the noise goes and comes and when accelerating and decelaration noise comes back

Next suggestion is EGR from that description. Take a look at all vacuum hoses, everywhere. Let me look at some stuff..will be back

ok tanks

Symptoms of failed EGR: Pinging and Knocking Pinging and knocking commonly result from increased engine temperatures. These increased temperatures cause pinging and knocking by creating a condition where the fuel and air mixture within a cylinder ignites prematurely. If an EGR valve is opening improperly, it can increase engine temperatures, causing the pre-ignition of the combustion process before the proper timing, resulting in engine knock. Best wishes.hope I was even a little helpful

wow dude, you rule! I'd have never gone there~EGR which opens up to reduce combustion temp not engaging...strange world we live in~!

ya gotta 'goose back'....hand out with the smileys, if you are going to get any "smileys" back....goose~