tapping sound when barely hitting the gas and other questions!

Hi,

honda prelude 2001, rebuilt engine.

When I just barely hit the gas, I get a sound like a rattle or tapping
sound from somewhere in the engine area. If I remove my foot, the
sound immediate stops the second my foot leaves the pedal. If I just
barely touch the gas pedal, just enough to maintain speed, the sound
occurs again. However, if I give it more gas, I cant hear the sound.
Either because the rest of the engine gets louder or the sound stops.

This sound starts occuring around 3000 rpm and gets louder the faster
the rpms. The best way to discribe the sound is like tapping on your
mouse with your fingernail about 5 times a second.

What can it be?

thanks.

 

The spash shield over the exhaust pipes at the front of the engine?

 

If the sound is totally gone when you're foot is off the gas, then I'd
think it may have to do with the engine shifting slightly when revved.
Maybe the motor mounts aren't tight enough. I'd have someone rev the
engine while you listen up front and see what you can see.

Dan D
'07 Ody EX
Central NJ USA

 

(I'm not the OP, but interested.)
Would that be tied to road speed or engine speed?
I have a noise in a 2003 Civic, 70,000 miles. I can hear it outside the
car as my wife drives away. I can hear it if I am driving, but just
barely, unless the engine is cold, and under a load.

I thought it was valve noise, so I had a valve adjustment done at 60,000
with no change in the noise. I left the car over night, but they couldn't
hear the noise the next morning. I should have gone in for the test drive,
but I thought they'd hear it.

If it's a shield, I should be able to affect it, or eliminate it by doing
"something" to the shield.

 

Someone else mentioned the same thing.

Are the motor mounts something that can be inspected while the engine
is still in?

 

Is this the shield with the Hand picture on it that says do not touch?
Can I safely remove these sheild temporarily to see if the sound goes
away?

thanks.

 

It may be. The bolts may be difficult to remove as they screw into very
hot parts of the engine. Old ones seem to rot away around the bolts
so the it leaves the shield loose and it rattles. A large washer may be
fitted to apply to captivate it again. The washer may need its edges
turning down to reach the shield.

HTH