Hello,my name is Shane and I'm new to the f150 community! I just bought a 98f150 cult with the5.4 triton motor with about 112k on it, the stock muffler was a little rusted so I bought a flowmaster 40 series muffler. After I got it back from the shop and I was driving home I got on it to hear the new muffler( who would say they wouldn't do that) and I happ to hear a slight tucking sound from the left side of the truck. I got home and popped the hood and started it, at idle there's no ticking at all, I gave it some gas and with no load it was quite as a mouse. So I hopped in and went for a drive and if I give it has hard the ticking come one hard, if I barely give it gas it's quite. Now, I did put some cheap gas in it (I know I shouldn't have but I did) so I'm hoping that's the deal, but I don know a bunch about this motor so any help would be awsome.

 

One thing that would greatly concern me is these engines have a habit of spark plugs loosening, and eventually blowing out. I would pull all 8 coils off and retorque the plugs to 28 ft/lb.

Another common source is an exhaust leak, usually the manifold to head, manifold to EGR pipe, or manifold to Y-pipe.

It may be spark knock, throw a tank of full premium in it and see if it stops.

You know the Fartmaster may sound good, but it actually kills some power! The stock muffler is actually lower restriction.

 

I checked the plugs and there re torqued down. And if was an exhaust leak I would figure it would make noise all the time not just under load and on the throttle,but I will check that. I did notice how ever that the left injection rail is making a sound that is very similar to the ticking I'm hearing. Just quieter. Also it seemed to me that my FLOWMASTER added more power, but it could be a placebo effect... If it is I will take it!!

 

Anyone else have an idea?

 

Im not sayin its not but seriously ? My stock muffler was like 4 ft long and like a foot in diameter and your saying that is less restriction than a flowmaster ? Not that i have one.. I personally have no muffler

 

UPDATE: After taking the day to look over the truck I got some new info. First I checked the plugs again and all was well, second I took stethoscope and listened to the injector rail and the noise is not coming from them. Next I and my wife put the truck in drive and hold the brake and feather the gas, I found out that it does not do it at idle and if just lightly push on the pedal, no noise all the way to 5000 rpm. Now if you stomp on the throttle it will make that ticking sound but it sounds more like an exhaust leak, so I looked on the left side of the truck and it looked like the egr tube is black as night.