It builds up on top of the pistons and in the combustion chambers. If an
engine is in good mechanical condition (rings, valve guides, etc.), and is
properly tuned, this isn't usually a problem. Add some oil or too much gas
(rich fuel mixture) and that's when things can go bad. There are
decarburizing chemicals that can be added to gasoline or even poured down
the carb/throttle body. Some old timers used to slowly pour ice water down
the carb while the engine was running, but I personally wouldn't advise
that.

Chris


"William Oliveri" <wuji@bigvalley.net> wrote in message
news:bl5vba$8cspv$1@ID-193866.news.uni-berlin.de...
> I'm curious about carbon build up. Where does carbon build up accumulate
> and how is it removed?
>
> Thanks,
>
> bill
>
> "Simon Juncal" <sjuncal@erols.com> wrote in message
> news:3F7671C7.5020409@erols.com...
> >
> >
> > William Oliveri wrote:
> > > I should mention I hear this the loudest when no torque is applied.
> That
> > > is, at idle and between shifting gears. I don't hear it when applying
> load
> > > either light or heavy.
> >
> > That's not pinging... pinging sounds a lot like someone rattling a spray
> > paint can under your hood as you depress the gas pedal (getting faster
> > as you rev higher). There's also "knocking" which is much like pinging
> > both are caused by fuel detonating before or after it SHOULD. I've heard
> > knock described as sounding like shaking "a coffee can full of marbles".
> >
> > > Is pinging more prominent under load? Does it get worse when more
load
> is
> > > applied?
> >
> > Yes very much so. It's often caused by your engine being starved for air
> > (overly rich fuel mixture), carbon deposits (they get red hot and become
> > basically an uncontrolled source of ignition). Fouled plugs (the carbon
> > on them can glow just like heavy carbon buildup causing the same
> > pre-ignition problem).
> >
> >
> > > What does pinging tell about an engine? Does it indicate something
> negative
> > > about an engine?
> >
> > A number of possibilities include; Carbon build up, timing being off or
> > worn/slipping timing belt/chain, running gas at a lower octane than what
> > the ignition system is design to use. Air starvation: clogged or dirty
> > air filter: clogged or malfunctioning air sensors (various types of air
> > flow sensors such as Mass Air etc.). A dirty enough throttle body, or
> Carb.
> >
> > Anyway what you describe isn't likely "ping" but it does sound a lot
> > like a sticky lifter, if the sound you're hearing is relatively rhythmic
> > but noticeable mostly when you're parked or moving slowly. It could be a
> > lifter. If the sound fades slowly in and out sometimes louder sometimes
> > quite. I'd bet on the lifter.
> >
>
>

 

That's not ping....

Ping happens under load and sounds like a rattling noise. It is caused
by too low an octane lighting up under compression. Folks go with a
higher octane to slow down the burn, so the gas waits for the spark plug
to light it up.

Or they adjust the timing back a bit to compensate like a knock sensor
does.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's


William Oliveri wrote:
>
> I should mention I hear this the loudest when no torque is applied. That
> is, at idle and between shifting gears. I don't hear it when applying load
> either light or heavy.
>
> Is pinging more prominent under load? Does it get worse when more load is
> applied?
>
> What does pinging tell about an engine? Does it indicate something negative
> about an engine?
>
> Thanks
>
> bill
>
> "William Oliveri" <wuji@bigvalley.net> wrote in message
> news:bl5idh$8ap23$1@ID-193866.news.uni-berlin.de...
> > Hi all,
> >
> > I just installed a MPI kit on my 83 CJ7 and all is fine. However, there
> > is a sound that is coming from the engine which I cannot determine what it
> > is. To me it sounds like belts moving but not really. Kinda hard to
> > describe. I've heard there's a problem with Pinging with MPI kits.
> >
> > What does pinging sound like? How can I determine if my engine is
> pinging?
> >
> > thanks in advance,
> >
> > bill
> >
> >

 

That's not ping....

Ping happens under load and sounds like a rattling noise. It is caused
by too low an octane lighting up under compression. Folks go with a
higher octane to slow down the burn, so the gas waits for the spark plug
to light it up.

Or they adjust the timing back a bit to compensate like a knock sensor
does.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's


William Oliveri wrote:
>
> I should mention I hear this the loudest when no torque is applied. That
> is, at idle and between shifting gears. I don't hear it when applying load
> either light or heavy.
>
> Is pinging more prominent under load? Does it get worse when more load is
> applied?
>
> What does pinging tell about an engine? Does it indicate something negative
> about an engine?
>
> Thanks
>
> bill
>
> "William Oliveri" <wuji@bigvalley.net> wrote in message
> news:bl5idh$8ap23$1@ID-193866.news.uni-berlin.de...
> > Hi all,
> >
> > I just installed a MPI kit on my 83 CJ7 and all is fine. However, there
> > is a sound that is coming from the engine which I cannot determine what it
> > is. To me it sounds like belts moving but not really. Kinda hard to
> > describe. I've heard there's a problem with Pinging with MPI kits.
> >
> > What does pinging sound like? How can I determine if my engine is
> pinging?
> >
> > thanks in advance,
> >
> > bill
> >
> >

 

c did pass the time by typing:
> It builds up on top of the pistons and in the combustion chambers. If an
> engine is in good mechanical condition (rings, valve guides, etc.), and is
> properly tuned, this isn't usually a problem. Add some oil or too much gas
> (rich fuel mixture) and that's when things can go bad. There are
> decarburizing chemicals that can be added to gasoline or even poured down
> the carb/throttle body. Some old timers used to slowly pour ice water down
> the carb while the engine was running, but I personally wouldn't advise
> that.

Erm.. don't use icewater, that is bad. Just plain ol water dribbled down
the intake is enough. The other is to use tranny fluid but it makes one
hell of a smoke cloud. Another approach is called a Ferrari tuneup. You
get up to speed and with the engine nice and warm, drop it one gear and
nearly redline. That breaks up the carbon and sends it scooting out.

--
DougW

 

c did pass the time by typing:
> It builds up on top of the pistons and in the combustion chambers. If an
> engine is in good mechanical condition (rings, valve guides, etc.), and is
> properly tuned, this isn't usually a problem. Add some oil or too much gas
> (rich fuel mixture) and that's when things can go bad. There are
> decarburizing chemicals that can be added to gasoline or even poured down
> the carb/throttle body. Some old timers used to slowly pour ice water down
> the carb while the engine was running, but I personally wouldn't advise
> that.

Erm.. don't use icewater, that is bad. Just plain ol water dribbled down
the intake is enough. The other is to use tranny fluid but it makes one
hell of a smoke cloud. Another approach is called a Ferrari tuneup. You
get up to speed and with the engine nice and warm, drop it one gear and
nearly redline. That breaks up the carbon and sends it scooting out.

--
DougW

 

Approximately 9/27/03 19:51, William Oliveri uttered for posterity:

> Hi all,
>
> I just installed a MPI kit on my 83 CJ7 and all is fine. However, there
> is a sound that is coming from the engine which I cannot determine what it
> is. To me it sounds like belts moving but not really. Kinda hard to
> describe. I've heard there's a problem with Pinging with MPI kits.
>
> What does pinging sound like? How can I determine if my engine is pinging?

The only time I've ever heard pinging that actually had a
"pingggg" type sound was on a turboCorvair. Most other cars
you just hear a sort of tick tick tick tick noise under
load.

Moderate ping won't hurt anything, where moderate is just a few
click noises as you hit the gas. Sustained ping tends to do such
nice things as ruining rods, rod bearings, or even put a hole right
in the top of the piston. The worst pinging is a higher speeds
where you can't hear it.

 

Approximately 9/27/03 19:51, William Oliveri uttered for posterity:

> Hi all,
>
> I just installed a MPI kit on my 83 CJ7 and all is fine. However, there
> is a sound that is coming from the engine which I cannot determine what it
> is. To me it sounds like belts moving but not really. Kinda hard to
> describe. I've heard there's a problem with Pinging with MPI kits.
>
> What does pinging sound like? How can I determine if my engine is pinging?

The only time I've ever heard pinging that actually had a
"pingggg" type sound was on a turboCorvair. Most other cars
you just hear a sort of tick tick tick tick noise under
load.

Moderate ping won't hurt anything, where moderate is just a few
click noises as you hit the gas. Sustained ping tends to do such
nice things as ruining rods, rod bearings, or even put a hole right
in the top of the piston. The worst pinging is a higher speeds
where you can't hear it.

 

Approximately 9/27/03 23:31, William Oliveri uttered for posterity:

> I'm curious about carbon build up. Where does carbon build up accumulate
> and how is it removed?

On the valves, pistons, and spark plugs. An old removal technique that
worked nicely for sports cars is the "Italian Tuneup" which works
for *light* carbon removal. Put in premium gas or add a good
detergent additive. Find a lonely road and from a dead stop,
head for the legal limit [or your paranoia speed] as fast as
you can. Goal being to run at wide open throttle and heavy
load to burn off the deposits. Won't work for heavy deposits
on valves or pistons very well, but you can usually feel it
work by the second or third time you run it up.

 

Approximately 9/27/03 23:31, William Oliveri uttered for posterity:

> I'm curious about carbon build up. Where does carbon build up accumulate
> and how is it removed?

On the valves, pistons, and spark plugs. An old removal technique that
worked nicely for sports cars is the "Italian Tuneup" which works
for *light* carbon removal. Put in premium gas or add a good
detergent additive. Find a lonely road and from a dead stop,
head for the legal limit [or your paranoia speed] as fast as
you can. Goal being to run at wide open throttle and heavy
load to burn off the deposits. Won't work for heavy deposits
on valves or pistons very well, but you can usually feel it
work by the second or third time you run it up.

 

You should do that within walking distance of home. ;-)
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/


DougW wrote:
>
> Erm.. don't use icewater, that is bad. Just plain ol water dribbled down
> the intake is enough. The other is to use tranny fluid but it makes one
> hell of a smoke cloud. Another approach is called a Ferrari tuneup. You
> get up to speed and with the engine nice and warm, drop it one gear and
> nearly redline. That breaks up the carbon and sends it scooting out.
>
> --
> DougW