AM radio EM interference
Thread Starter
Instructor
Joined: Sep 2011
Posts: 115
Likes: 0
From: MI
AM radio EM interference
Lately, I'm getting whirlling/static sound from AM stations with change in EGRPM when I drive the car. It didn't do that before.
Is this the sign of a bad spark plug wire?
thanks for any input.
Is this the sign of a bad spark plug wire?
thanks for any input.
Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 594
From: Prescott, Arizona
I had the same problem, which has been greatly reduced but not eliminated. In town, I have no problem, but as I get closer to home which is 17 miles out in mountainous country, there is still some AM only spark static (true on all four of my cars).
I first changed spark plugs and wires, which helped somewhat. Perhaps some of the improvement realized here is that I left the gap on the new irridium plugs at 0.040, and did not widen the gaps to 0.60. Two road course track days say this gap is OK.
I then cleaned and dialectric greased EVERY ground on the car, which seemed to help a little. Probably other benefits accrue from this activity also.
In the course of installing a satellite radio I took the opportunity to install an antenna filter. This action helped the most. Antenna filters are available from Radio Shack, Crutchfield et al. Keep in mind that for this action, you will need male and female adaptors to adapt the GM antenna lead to the filter and then the filter to the radio.
If you decide to install the antenna filter, don't forget that when you move the console back for clearance to remove the radio finish panel, you are somewhat likely to accidently dissconnect the fuel door switch plug which plugs into the underside of the console. Easily avoided or replugged if you are aware.
I first changed spark plugs and wires, which helped somewhat. Perhaps some of the improvement realized here is that I left the gap on the new irridium plugs at 0.040, and did not widen the gaps to 0.60. Two road course track days say this gap is OK.
I then cleaned and dialectric greased EVERY ground on the car, which seemed to help a little. Probably other benefits accrue from this activity also.
In the course of installing a satellite radio I took the opportunity to install an antenna filter. This action helped the most. Antenna filters are available from Radio Shack, Crutchfield et al. Keep in mind that for this action, you will need male and female adaptors to adapt the GM antenna lead to the filter and then the filter to the radio.
If you decide to install the antenna filter, don't forget that when you move the console back for clearance to remove the radio finish panel, you are somewhat likely to accidently dissconnect the fuel door switch plug which plugs into the underside of the console. Easily avoided or replugged if you are aware.
Safety Car
Joined: Jan 2001
Posts: 4,386
Likes: 689
From: Boise ID
