engine tapping ...oh no

[IndianaVX]

thanks joe for taking intrest...........
i would say, ball bearing on plate, or glass, rapid tapping, for just a few seconds, like ten or so, then i reved, and it went away. when the rev idled down, it was gone. it was evident enough that my brother, who knows nothing about engines, said "that sounded weird, you still have a warranty?" gulp......
using Mobil 1 10-30.....weather is warming up...it was about 60.

[Y33TREKker]

Are you sure it was a mechanical tapping and not an electrical snapping? Maybe something in the ignition?

[IndianaVX]

well, does the coil pack make any tapping noise??? i mean im pretty durn sure it was mechanical, but ive never dealt with these coils over plug setups..... i suppose it could be a rapid snap snap snap snap noise. also, when i started it up this morning, i heard the slightest of rattleing of sheet metal. dont think its related, but i dont know. havent been home again since this morning to check it out.....
thanks guys, ill keep answering if you keep asking....

thanks again,
david

[Tobert]

It could be valve adjustment. Mine taps like crazy, especially on lighter weight oils.

[Y33TREKker]

It could be valve adjustment. Mine taps like crazy, especially on lighter weight oils.

I was just throwing out ideas with the electrical snapping idea. I guess I had just assumed that the 3.5L VX motor used hydraulic lifters, but I see from the cd manual that a solid lifter bucket/shim type adjustment is used, so valve adjustment could very well be the cause.

How many miles on the engine? VX valve adjustment intervals are every 60k miles.

[IndianaVX]

just rolled 63000..........

[Ldub]

Check your exhaust system to find the most likely cause of the sheet metal rattling sound...the heat shield(s) are a known culprit.