Knocking noise :/
 

First off, I am glad to be a new member here. I hope you guys will be more helpful then the other ford truck forums! So basic info on me, I am 20 and live in San Diego, i just recently bought a 98 f150 a few months ago.

Truck: f150
year: 1998
Miles: 200k
engine: 1997 4.6L V8 Windsor SOHC 100k miles

Now here is the problem, A month or so ago i started hearing this knocking/clicking sound on cold start, it lasted for about 1-3mins. Once the engine has warmed up the sound stopped. Then over time it started to get louder.

I did find a small leak on the EGR tube so i replaced the tube and still have the sound. I replaced the oil with motorcraft 5w30 with a motorcraft 820s filter, the sound is still present. None of the studs are rested on the manifold and still intact. I cleaned the EGR valve, and cleaned the PCV Valve and no luck with that. Does not seem to be a exhaust leak as i used the hose trick and did not hear any leaks.

While replacing the oil i did notice the coolant was low and black, I will be flushing it tomorrow, along with checking spark plugs to make sure there not loose.

As of right now i am lost on what it could be, I read that the windsor engines had problems with piston slap could this be my problem or lifters? What are my next steps to figuring out this problem?

here is video of the noise:
44F9A78B-8CD9-4508-AB74-ADD78801CE62-12734-00000E43D2E36580.mp4 video by peezybro1 - Photobucket

100 views and no responses ?

if it was your heads knocking you would hear it in the high end not low end and if it was your pistons it would be more dull sounding i think it might be your low end pobly your crank bearings.. i would just open up the crank case and check it out you might be surprised what you find laying around in the botton of you oil pan.

i was able to get a stethoscope, and heard the noise the loudest on the drivers side valve cover, closer to the back of the engine. So my bet is a sticky 'lifter' (i know my engine has lash adjusters and rocker arms, but its easier to say lifters) or failed lifters.

Before i take of the valve cover to check the valve train, could i use anything to help them? like Lucas oil stabilizer, slick 50, some type of additive to help quiet them down?

still cant figure out what the noise could be. and i am not sure if i should take the valve covers off or not.... any advice!

http://i1128.photobucket.com/albums/...CD1FD257CC.mp4