Engine Buzzing ignition coil?

7upper

New Member
Mar 21, 2021
3
0
1
38
Lincoln, RI
Hi all,

This past weekend I replaced the cap, rotor, ignition wires, and coil on my 1990 5.0. The car has 87k miles on it and when I pulled the cap and rotor they appeared to be original to the car.

I had no issues prior to the swap other than an occasional long crank time to start. After replacing the coil cap rotor and wires, I now have a buzz coming from the coil, identified by using a piece of wood as a stethoscope and isolating the buzzing to the coil itself.

The coil I used was an inexpensive autozone brand one so I figured it was poor quality, so I sourced a new OEM Motorcraft unit from Amazon to replace it with. The buzzing did not go away upon replacing with the Motorcraft one, so I find myself a bit stumped.

Foolishly I threw away the original wires and coil so i can't reinstall them. Grr!

Any ideas what would cause the buzz? Can anyone recommend a quality aftermarket coil?

Thanks in advance !
 
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Shakerhood

15 Year Member
Oct 28, 2004
3,298
177
114
Ohio
I have an Aftermarket Coil in my car, think its MSD. It also makes a weird electrical type buzzing noise too, but its been in the car for about 20 years so it obviously doesnt hurt long term reliability.
 

7991LXnSHO

Now I want a 10 year badge
10 Year Member
Sep 1, 2010
4,324
1,173
184
Kearney, NE
MSD redesigned and warranted the buzzing coils. If the core or wires move separately from the mount, it will buzz. If not, try punching some washers out of an inter tube as mounting pads.
 
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Redfire Fox

Active Member
Dec 29, 2011
53
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My old MSD coil made a loud buzzing noise the entire time I had it but later crapped out on me. Got an Accel coil and its quiet with no complaints.