Interference on FM after exhaust replacement on Honda Accord

Hi,

I recently had the mid-section on my 97 Accord exhaust replaced, and since
then I have been getting intermittent FM radio reception problems
(crackling, poor signal/tuning, general hiss or mono signal). This could
obviously be a coincidence, but I thought I'd ask first whether there is any
way an exhaust part could affect radio reception (I feel slightly silly
asking BTW).

I guess another possibility is a poor ground somewhere, or my aerial decided
to break the same day, although it affects music delivered by my inline FM
modulator as well? I thought maybe the stereo is on its way out, but the CD
changer plays perfectly. I'm having trouble thinking how to troubleshoot
this one!

Thanks in advance for any suggestions,
Al

In article >,
Al Reynolds > wrote:
> I recently had the mid-section on my 97 Accord exhaust replaced, and
> since then I have been getting intermittent FM radio reception problems
> (crackling, poor signal/tuning, general hiss or mono signal). This
> could obviously be a coincidence, but I thought I'd ask first whether
> there is any way an exhaust part could affect radio reception (I feel
> slightly silly asking BTW).

> I guess another possibility is a poor ground somewhere, or my aerial
> decided to break the same day, although it affects music delivered by
> my inline FM modulator as well? I thought maybe the stereo is on its
> way out, but the CD changer plays perfectly. I'm having trouble
> thinking how to troubleshoot this one!

> Thanks in advance for any suggestions,

Exhaust systems can act as an aerial and radiate interference. To prevent
this some have earthing straps. But it's a long shot. I'd say it's
unlikely any of the car aerial etc wiring goes anywhere near the exhaust
so shouldn't have been damaged or disturbed when fitting a new one, so
it's likely just coincidence.

If it uses an aerial built into the rear screen etc there will be a RF amp
associated with this and the likely cause of the problem - poor connection
or simple failure.

--
*Gun Control: Use both hands.

Dave Plowman London SW
To e-mail, change noise into sound.

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Al Reynolds" >
saying something like:

>Thanks in advance for any suggestions,

In addition to what Dave suggests, I'd also have a look at any
suppression caps or earth straps that might be fitted under the bonnet
or under the floor - they might have been dislodged by the Kwack Fart
fitters.

Al Reynolds wrote:
> Hi,
>
> I recently had the mid-section on my 97 Accord exhaust replaced, and
> since then I have been getting intermittent FM radio reception
> problems (crackling, poor signal/tuning, general hiss or mono
> signal). This could obviously be a coincidence, but I thought I'd
> ask first whether there is any way an exhaust part could affect radio
> reception (I feel slightly silly asking BTW).
>
> I guess another possibility is a poor ground somewhere, or my aerial
> decided to break the same day, although it affects music delivered by
> my inline FM modulator as well? I thought maybe the stereo is on its
> way out, but the CD changer plays perfectly. I'm having trouble
> thinking how to troubleshoot this one!
>
> Thanks in advance for any suggestions,
> Al

most japanese and many english cars have an exhaust earth strap, if it isn't
there, add one. any non earthed part can give interference, including
wheels! some vehicles have a brush in the hub bearing cap to avoid this.

"Mrcheerful" > wrote in
m:

> Al Reynolds wrote:
>> Hi,
>>
>> I recently had the mid-section on my 97 Accord exhaust replaced, and
>> since then I have been getting intermittent FM radio reception
>> problems (crackling, poor signal/tuning, general hiss or mono
>> signal). This could obviously be a coincidence, but I thought I'd
>> ask first whether there is any way an exhaust part could affect radio
>> reception (I feel slightly silly asking BTW).
>>
>> I guess another possibility is a poor ground somewhere, or my aerial
>> decided to break the same day, although it affects music delivered by
>> my inline FM modulator as well? I thought maybe the stereo is on its
>> way out, but the CD changer plays perfectly. I'm having trouble
>> thinking how to troubleshoot this one!
>>
>> Thanks in advance for any suggestions,
>> Al
>
> most japanese and many english cars have an exhaust earth strap, if it
> isn't there, add one.



Al's exhaust grounds through a bolted flange just behind the oil pan.

However, Al may want to check for the existence and integrity of the engine
ground strap. This item will attach to a valve cover nut and go to either
the rad support or a shock tower. It's common for these to break or get
left off entirely.



--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

"Mark" > wrote in
:

>
> "Tegger" > wrote in message
> ...
>> "Mrcheerful" > wrote in
>> m:
>>
>>> Al Reynolds wrote:
>>>> Hi,
>>>>
>>>> I recently had the mid-section on my 97 Accord exhaust replaced,
>>>> and since then I have been getting intermittent FM radio reception
>>>> problems (crackling, poor signal/tuning, general hiss or mono
>>>> signal). This could obviously be a coincidence, but I thought I'd
>>>> ask first whether there is any way an exhaust part could affect
>>>> radio reception (I feel slightly silly asking BTW).
>>>>
>>>> I guess another possibility is a poor ground somewhere, or my
>>>> aerial decided to break the same day, although it affects music
>>>> delivered by my inline FM modulator as well? I thought maybe the
>>>> stereo is on its way out, but the CD changer plays perfectly. I'm
>>>> having trouble thinking how to troubleshoot this one!
>>>>
>>>> Thanks in advance for any suggestions,
>>>> Al
>>>
>>> most japanese and many english cars have an exhaust earth strap, if
>>> it isn't there, add one.
>>
>>
>>
>> Al's exhaust grounds through a bolted flange just behind the oil pan.
>
> At DC yes it is grounded via the engine,
> but at 100MHz the impedance
> along the exhaust is high and all sorts of radio noise (clicking
> crackling) could build up along it. On some cars the manufacturer may
> have found they needed to add a ground strap at some point along the
> exhaust to stop interference.
>


Honda does not do this, to my knowledge. I've never seen such a thing on a
Honda exhaust.


--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/