I have an 03 f-250 V10 and it sounds like i have a bad lifter when i am driving right about 2500 rpm before it shifts no noise below that rpm.Fresh oil, not towing.How do I go about diagnosing and fixing this problem.It has 136000 miles on it.Any help would be great.

 

What makes you think it's a lifter? What is it doing or sounding like? Sometimes an exhaust leak can sound like a noisy lifter. Starting on the outside of the engine and working your way inside can help eliminate possible problems. Are there any broken exhaust bolts/studs? If it truly is a lifter could a stethoscope help pin point the problem area? Are there any CEL on? Maybe someone else can chime in.

 

Lifter noise isn't generally that RPM specific, I agree with starting outside of the engine first and with an RPM specific noise I'd start with the exhaust heat shields. It's common for them to break at the spot welds and rattle at certain RPMs.

 

Thanks guys for your suggestions.I will pick up a stethoscope and also check the exhaust.I do have the heat shield rattle but I know that is not what is making the sound it sounds more like a tapping noise.

 

Some have reported tappity-tap sounds just prior to a spark plug spitting. Maybe something worth checking?

 

Well I checked the plugs and exhaust and they are both fine also could not pick up anything with the stethoscope.It only makes the noise when driving.I can rev it in the driveway and it does not make the noise. I am a little perplexed any other ideas?

 

Does it have the stock exhaust manifolds and and stock y pipe? (the ypipe that is necked down at two points) That is close to the rpm where I have always noticed exhaust flutter, which is very rpm specific and only in a narrow rpm range.

 

Yes it is all stock.What do you mean by exhaust flutter does it sound like a bad lifter?

 

If it has the stock necked down ypipe it is highly unlikely it has flutter. The necked down ypipe is good at 2 things, killing the exhaust flutter sound and killing power. Exhaust flutter is hard to describe but it kind of sounds like an exhaust leak that comes on all of a sudden in a short rpm range somewhere between 2000-3000 rpm.