Slapping sound when WOT from stop (1 Viewer)

[ElJefe]

well its still there but the truck runs mint. I dunno, i think there is a micro crack in exhaust manifold and its causing the tapping noise. I am going to bring it to the toy dealer when i get a chance to get it checked out.

It looks like this problem has been going on for a while. How long have your spark plugs been in??? If they have been in for a while with this knock business going on, get a new set and pull your old ones. If you have been having a serious detonation issue for the last 6 months, your plugs will have little hard white deposits speckled all over them.

If it only happens over 3.5K maybe your fuel pump relay or fuel regulator is bad... both would provide an under pressure situation at upper RPM's under load.

My first step would be the plugs to verify IF it is a detonation problem, and which cyclinder or all cylinders.

 

[IdahoDoug]

I wouldn't bother with the seafoam. I think you've got some physical interference with a drive shaft, or something else that gets pulled out of position at WOT. Another wierd cure for slapping sound was the rubber splash guards in the front fenders that were not secured. No WOT connection, though.

DougM

 

[Spydaz]

Well i did do the Seafoam and she smoked quite well LOL. Then i went home dropped the oil and did an oil change and much to my surprise the noise is not there anymore. Mabey the seafoam, maybe the oil change??? Have no idea.

I personally think that there is a micro crack in the y pipe on the headers or near the headers becuase when i had that cat problem and had to stop on the freeway the damn exhaust manifolds were cherry red (cats were bad) So i think there may be a crack casued from the exessive heat from the cats being clogged up. One thing i notice is that it only does that ticking, knocking, tapping noise when the truck has been running for some time and is heated up good (like driving for an hour on a freeway) so that leads me to beliveve that whatever it is it is caused by the heat expanding the metal some where revieling a crack in the upper exhaust or exhaust manifold.

I will see, but if the sound gets worse i will have to weld the y or take the protective cover off the manifold and look around.

ehat about the EGR could that have a crack?? I hear it comming from that area.