Hi all. THe problem is occuring on my 1994 F-350 with a 460 under the hood. There is a noise occuring when the engine is cold. (The best way to describe it is like putting playing cards in your bicycle spokes and having them slap the bike.) It will happen for maybe two miles of 40 MPH driving then taper off. It also happens when I drive for a while and shut the vehicle off and let it sit for a few minutes. To me it sounds like the il is not coating something in the engine (sorry...I am still learning a lot about my truck and I am not a engine specialist). Now, I am contemplating using a heavier weight of motor oil on my next change. Will this hurt the engine, or how do I determine what else could be done. Thanks for all of the great help on here. I appreciate it.

 

from what it sounds like, u may have some lifter tap. check out this thread for some advice.

https://www.ford-trucks.com/dcforum/61_79/11892.html



1977 F250 460
C6 Hedman Headers
Dual 40 series
edelbrock performer
holley 4150
msd 6a and blaster coil

 

 

Could also be the exhaust manifold leaking. Mine clicks/clacks until engine is hot enough to seal the leak. Fix is to remove the manifold and have it machined flat -if it is warped. Other cause of leak could be manifold bolt broken off - that's my case. The fix for that is to drill out broken bolt, rethread, and install new bolt. Or live with it!