Motor tapping question
Thread Starter
Pro
Joined: May 2005
Posts: 592
Likes: 1
From: Shreveport Louisiana LSU
Motor tapping question
I saw the thread the other day about this. I used a pvc tube all around the engine and do believe all of my tapping is actually exhaust leaks on the passenger side of my 81. But, with the car running, I felt and the fuel pump and could feel a lots of tapping there. I couldn't really hear it with the tube. Question is, how smooth should the fuel pump be, and could this rythmic vibration be caused by a worn fuel pump rod or perhaps a weak spring on the fuel pump. How many of you have felt your fuel pump?
Heel & Toe
Joined: Oct 2005
Posts: 19
Likes: 0
From: Gwynedd Valley PA
My fuel pump went bad a while ago and sounded exactly like a bad lifter. Much easier to fix than a lifter, though! 
I remember I could hear it clearly using a cooling hose. The noise was prominent around the valve cover, but when I fished it down to the fuel pump it sounded like I was in the first row of the orchestra.
Recently, though, I've invested in one of those automotive stethoscopes. Those things work much better than hoses, IMHO. Definitely worth the $10. It has already paid for itself with other engine noises.
If you are listening for an exhaust leak with a stethoscope, remove the probe and use just the open end of the hose. You are listening for sound waves, not metal-to-metal contact.
I remember I could hear it clearly using a cooling hose. The noise was prominent around the valve cover, but when I fished it down to the fuel pump it sounded like I was in the first row of the orchestra.
Recently, though, I've invested in one of those automotive stethoscopes. Those things work much better than hoses, IMHO. Definitely worth the $10. It has already paid for itself with other engine noises.
If you are listening for an exhaust leak with a stethoscope, remove the probe and use just the open end of the hose. You are listening for sound waves, not metal-to-metal contact.
