[RFI] Spark plug noise
Eric Gustafson <email@example.com>
Fri, 7 Jul 2000 13:46:50 -0700
You could always replan your trips so that they don't require
right turns ;-).
Actually, I have had this happen in a number of older cars. The
cause was not the same in each case. The four main things to
check are (not in order of probability):
1. Good bonding between the radio case ground and the vehicle
frame local to the radio. Note this is not the same path as
power ground in most cases. This should be an actual short
2. Proper bonding strap connections between the engine block and
vehicle frame and firewall. You might want to check your
motor and tranny mounts while you're at it. They might be
permitting too much travel. But you'd likely have a forward
vs reverse component to the problem if this was the cause.
3. Proper bonding between firewall and fenderwell sheet metal
4. Secure ground connection for the antenna feedline to the
vehicle body at the antenna. This includes antenna feedline
shield integrity from the radio to the body sheet metal. If
this is the cause, and it is due to a loose antenna mount to
the sheet metal, you can duplicate the problem sitting still
at idle by gently forcing the antenna to the left or right.
The last one being the most likely cause, IMHO.
73, Eric N7CL
>Date: Fri, 07 Jul 2000 14:51:45 -0500
>From: firstname.lastname@example.org (Kelly Boswell)
>Anybody heard of one like this;
>My 90 Nissan pick-up has spark-plug noise on the AM radio, but
>*ONLY* when turning right.
>1.) The sound is like your typical spark-plug noise.
>2.) Using a turn signal makes it worse. Also, it doesn't take
> much of turn for it to occur. Merely enough right turn to
> exit from an interstate will suffice.
>3.) None of this happens when turning to the left.
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