Spark plug pic's

[Craig Dotson]

> Sort of on subject - - I drive a '99 Dodge as a company truck sometimes.
> Since it was new it always had pinging - usually while at cruise in OD and
> increase load.  Pinging makes me cringe and I looked into it, thinking we
> needed to get it fixed.  However, I was surprised to find that the manual
> specifically states that slight audible pinging is NORMAL!  I don't
service
> the truck personally, but I would like to see what the plugs look like.
>
> In the early 70's, the Ford 351W's were really bad about pinging very much
> like this Dodge.  It was due to the EGR - normally it was either stuck or
> the vacuum hose was disconnected ;)  I don't know why Dodge considers this
> normal.  I agree that any car built in the last 15 years or so, should not
> have audible pinging.  Just a couple of cents . . .

I've been a regular poster/reader/learner on a Dodge truck list for about 2
years now.  Pinging is a VERY common problem, but the service people are
always required to do something to correct pinging on a vehicle that is
under warranty.  They'll try to tell you "they all do that" but they're
lying (it's only common, about 50% of 'em do that), and then they'll try to
tell you "we couldn't recreate the problem" but they're lying, just take 'em
for a ride (these are 2 of the many Chrysler standard excuses from their
notoriously crappy service departments).

The vacuum leak is most likely the correct case.  More often than not, these
Rams have a bad intake manifold gasket (there are multiple ones due to the
funky "beer keg" intake design).  This causes several problems: sucking in
more air, and oil leaking into the intake ducts.

There is a Dodge TSB for this.  There's also TSBs to re-route spark plug
wires to reduce cross-fire, and multiple revisions of a TSB to retard spark
timing.  The unanimous opinion is that the spark retard ECM flash is a BAD
thing!  Most people with the 5.9 Magnum that experiences pinging switch to a
180 thermostat and run 93 octane fuel.  The 5.2 Magnum doesn't have as much
problem with pinging as the 5.9 does.  I do know that the 5.2 has a 1.80:1
rod/stroke ratio, often cited as providing superior octane tolerance, among
other things.  Don't know how much that has to do with difference in
pinging.  Both engines go to open-loop at WOT, but I don't know if anyone
has measured the AFR at WOT.

If you want to look up TSBs on the truck (don't see why, but your employer
might) check out www.dodgeram.org for anything you want to know about the
trucks.

Craig Dotson
crdotson at vt.edu
2002 VT FormulaSAE

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