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rmcintosh 03-07-2007, 04:35 PM I have a 99 f150 with a 5.4l, which is overhead cam on both heads. just in the past two days it has developed a slapping sound in the passenger front side of the valve cover upon starting the goes away in just a minute. then returns upon starting again, then away within a min. The closest thing i can relate this sound to is the sound of a hydraulic lifter that has collapsed. Anyone know much abouth these motors or experienced this that has useful advice? thanks ford_n_toy 03-07-2007, 04:59 PM my 98 does the same thing, the noise that is,,,,, but its not the lifters, its the manifold, and it only does it on start up because the manifold is cracked and when they heat up the metal exspands and the crack seals.... this just my truck yours could be diff... rmcintosh 03-07-2007, 05:34 PM The exhaust manifold? i'm assuming? that is what my dad thought that it was. When it is hot it sounds like there is a small exhaust leak? guess i'm going to have to tear into this motor that is foreign to me. anyone else that has any ideas let me know. thanks a mill. adrianspeeder 03-07-2007, 06:03 PM Common apparently with the 5.4/6.8L http://www.f150online.com/forums/showthread.php?t=268870&highlight=piston+slap Adrianspeeder Offrhoder4x4 03-07-2007, 06:48 PM My work truck developed the slap when cold at around 50k. Checked everything out and all was well. Sitting with over 100k on it now and no issues. I would just rule everything else out before you decide it's the common slap. rmcintosh 03-07-2007, 10:35 PM Well upon some more looking into this i got home and was walking into the house past where i had parked a couple night ago and there was a nice broken exhaust stud laying on the ground. hopefully this is the problem. f250rollinon37s 03-07-2007, 10:55 PM verry common on ford modular engines - have fixed a few - my 95 5.8 has had a cracked manifold for over 3 years - i know what a pain it will be - si it can wait untill the engine blows :flipoff2: ford_n_toy 03-07-2007, 11:51 PM i replaced three right side manifolds with in 20k, everytime i changed one i broke at least two studs off in the block, what a bitch:shaking: :eek: the one on there now has been cracked for over 70k and havent had a porblem, Except When i go to start my truck up when is cold and it sounds like a fucking 300lb frog getting choked to death for about 5 seconds. then its like nothings wrong...:flipoff2: :flipoff2: . BrokeCuzWheelin 03-09-2007, 11:52 AM Exhaust manifold studs rust off on those all the time. Ford has updated studs and manifolds that won't rust off right away available. | |