Re: Plug Knock


"Whoever" <nobody@xxxxxxxxxxxx> wrote in message
news:Pine.LNX.4.63.0508241307410.21418@xxxxxxxxxxxxxxxxxxxxxxxx
>
>
> On Tue, 23 Aug 2005, Ted Mittelstaedt wrote:
>
> >
> > "Tom Rogers" <jeditom@xxxxxxxxxxxxxxxxxxx> wrote in message
> > news:uyKOe.35483$EX.12641@xxxxxxxxxxxxxxxxxxxxxxx
> >> Also on my 2005 Dodge Caravan, I have been getting a little spark plug
> > knock
> >> going up hills when it kicks into overdrive while on Cruise Control -
only
> >> with the AC on.
> >>
> >> Suggestions?
> >>
> >
> > Try a tank of premium or a few tanks of whatever gas your buying plus
> > octane booster and see if the problem goes away. If so then
> > congratulations -
> > you got an engine that has a hair's breath higher compression ratio than
> > it's brethern - maybe the milling machine that mills the heads on the
> > assembly line was out of adjustment that day - so if you are willing to
> > buy the gas for it you will get a bit more power out of it.
> >
>
> Many years ago, when I worked on knock dection systems, I was told by
> engine designers that ngines running under light knock conditions produce
> MORE power
>
> I believe your statement that if the OP buys higher octane gas he will get
> higher power is false.

You are so right, acually running a high octane fuel in this car will do
more damage then good, It will leave deposits that can cause higher
compression , causing pinging and even stalling problems

>
> Higher octane gas can allow engines to produce more power, but only
> because adaptive ignitions systems can advance the timing further when
> running on high octane gas. From what I was told by those engine
> designers, if the OP eliminates the knock by increasing the octane
> rating, the power output will actually drop! Remember there is no more
> energy stored in a gallon of high octane gas than is in a gallon of low
> octane gas.
>
> Now, I have also heard knock from my Voyager's 3.3L engine. It could be
> that I also have a faulty knock sensor, although there are no fault codes
> to indicate this. I suspect an alternative, which is that the programming
> of the engine management only allows gradual changes in timing due to
> knock detection, and thus a change in driving style (for example from
> light town driving to going up a steep incline at speed) causes a
> transient case of knock.
>


.

Relevant Pages

  • Re: Plug Knock
    ... > Many years ago, when I worked on knock dection systems, I was told by ... > I believe your statement that if the OP buys higher octane gas he will ... > get higher power is false. ... Just how much knock is "light knock"? ...
    (rec.autos.makers.chrysler)
  • Re: Plug Knock
    ... If so then congratulations - you got an engine that has a hair's breath higher compression ratio than it's brethern - maybe the milling machine that mills the heads on the assembly line was out of adjustment that day - so if you are willing to buy the gas for it you will get a bit more power out of it. ... I believe your statement that if the OP buys higher octane gas he will get higher power is false. ... Higher octane gas can allow engines to produce more power, but only because adaptive ignitions systems can advance the timing further when running on high octane gas. ... From what I was told by those engine designers, if the OP eliminates the knock by increasing the octane rating, the power output will actually drop! ...
    (rec.autos.makers.chrysler)
  • Re: Plug Knock
    ... >> gas was actually detrimental to a modern car engine. ... >> knock sensor actually needed to sense a slight knock (which they stated was ... "Lean burn" was leaner than earlier carbs, ...
    (rec.autos.makers.chrysler)
  • Re: mercruiser 120 engine knock expert wanted!
    ... In an attempt to trace an engine knock which is ... and valves re-cut and ground to perfection, oil seals, valve guides ok. ... Who's gonna have a crack at diagnosis and rid me of this noise? ...
    (rec.boats)
  • Re: mercruiser 120 engine knock expert wanted!
    ... In an attempt to trace an engine knock which is ... and valves re-cut and ground to perfection, oil seals, valve guides ok. ... Who's gonna have a crack at diagnosis and rid me of this noise? ...
    (rec.boats)
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