still just me <wheeledBobNOSPAM@[EMAIL PROTECTED]
> wrote in
news:ard8v3laa94roq6ml9a9vj9u65j4ej63pp@[EMAIL PROTECTED]
> On 3 Apr 2008 00:27:10 GMT, Jim Yanik <jyanik@[EMAIL PROTECTED]
> wrote:
>
>>COILS are not considered -electronic- devices(electrical,not
>>electronic),and are not "sensitive",even "moderately".
>>"electronics" would be the ECM and the semiconductor circuits that
>>switch the coil primary current.
>
>>Problems coils have are bad windings or bad
>>encapsulation/insulation,or improper currents applied to them.(an
>>external problem,not of the coil itself).
>
> I'd agree that a coil of wire is unlikely to go bad unless shorted,
> etc. FWIW, some do have small switching devices in them.
>
> The bottom line is that there is an unreasonably high failure rate
> (MHO) on these coils. It's not a strict manufacturing issue when it
> takes 60K or more miles (or the related time baking) for them to go.
> Perhaps the bad ones have bad tolerances, but then the manufacturing
> process has fairly major issues, and across manufacturers. I'd think
> that it was unlikely so many manufacturers just couldn't get it right
> - and it's the design that is just inherently prone to failure from
> heat and vibration.
>
>
>
if the coil was potted properly,vibration should not be a problem.
It's possible the potting compound(epoxy) is aging and becoming
brittle,and
cracking under thermal cycling.
I suppose one could create some coil mod where the actual coils are off
the
motor and a short wire from each coil to the plug,eliminating some of the
heat and vibration.
BTW,one Nissan forum I visited cited a Nissan emissions warranty as
covering failed coil packs.It seems there's a TSB on it;NTB01-059
It is for 2000-2001 Maximas.
--
Jim Yanik
jyanik
at
kua.net
|
