Ignition advance value for Caravan

Hi,

I drive a 2005 Dodge Grand Caravan SXT 3.8L
I am concerned about the engine detonation (pinging), that was very
heavy in summer, especially with A/C on, and sometimes it can be heard
even during cold weather.

Recently I've purchased an OBDII -> USB adaptor to hook up the laptop
and see the diagnostic data.

I discovered that the ignition advance is about 20 to 24 degrees when
idling, and it goes up to 40 to 50 degrees when revving up to 2000 RPM
(in neutral, engine warmed up to norm).
I believe that such values are way too high, and premature spark can
easily be the reason for detonation.

Could somebody advise what are the correct ignition advance values for
such conditions ?
Maybe any ideas how to troubleshoot further ?

Thanks a lot !!
Val

"Maus" > wrote in message
...
> Hi,
>
> I drive a 2005 Dodge Grand Caravan SXT 3.8L
> I am concerned about the engine detonation (pinging), that was very
> heavy in summer, especially with A/C on, and sometimes it can be heard
> even during cold weather.
>
> Recently I've purchased an OBDII -> USB adaptor to hook up the laptop
> and see the diagnostic data.
>
> I discovered that the ignition advance is about 20 to 24 degrees when
> idling, and it goes up to 40 to 50 degrees when revving up to 2000 RPM
> (in neutral, engine warmed up to norm).
> I believe that such values are way too high, and premature spark can
> easily be the reason for detonation.
>
> Could somebody advise what are the correct ignition advance values for
> such conditions ?
> Maybe any ideas how to troubleshoot further ?
>
> Thanks a lot !!
> Val

I think most engines for some time now have used "knock sensors" to let the
computer know to use less advance. Yours may not be getting the message
across.

I've never heard one knock from either of the 3.8s I have (2000 and 2008).

Good luck,
Pat

is it a flex fuel vehicle???

Maus wrote:

> Hi,
>
> I drive a 2005 Dodge Grand Caravan SXT 3.8L
> I am concerned about the engine detonation (pinging), that was very
> heavy in summer, especially with A/C on, and sometimes it can be heard
> even during cold weather.
>
> Recently I've purchased an OBDII -> USB adaptor to hook up the laptop
> and see the diagnostic data.
>
> I discovered that the ignition advance is about 20 to 24 degrees when
> idling, and it goes up to 40 to 50 degrees when revving up to 2000 RPM
> (in neutral, engine warmed up to norm).
> I believe that such values are way too high, and premature spark can
> easily be the reason for detonation.
>
> Could somebody advise what are the correct ignition advance values for
> such conditions ?
> Maybe any ideas how to troubleshoot further ?
>
> Thanks a lot !!
> Val

> I think most engines for some time now have used "knock sensors" to let the computer know to use less advance. Yours may not be getting the message across.
Yes, I know it uses the knock sensor to avoid the detonation. But my
mechanic does not believe it is faulty. Also no trouble codes are
stored in the vehicle - all clear...
Do you have an idea how to perform the basic diagnostic/
troubleshooting of the knock sensor ?

> I've never heard one knock from either of the 3.8s I have (2000 and 2008).
That's what I've had before fall '07, when a strange soft noise
appeared in the front end and detonation began to progress in summer
'08 during hot weather.
I still do not know what emits the noise and nobody can help me with
that. I feel that I'll have to pay Chrysler for a complete diagnostic.

Thank you,
Val

On Dec 7, 10:03*am, man of machines > wrote:
> is it a flex fuel vehicle???
No, the regular one. Does this tell anything to you ?

Thanks,
Val

On Dec 7, 8:20*am, Maus > wrote:
> > I think most engines for some time now have used "knock sensors" to let the computer know to use less advance. Yours may not be getting the message across.
>
> Yes, I know it uses the knock sensor to avoid the detonation. But my
> mechanic does not believe it is faulty. Also no trouble codes are
> stored in the vehicle - all clear...
> Do you have an idea how to perform the basic diagnostic/
> troubleshooting of the knock sensor ?
>
> > I've never heard one knock from either of the 3.8s I have (2000 and 2008).
>
> That's what I've had before fall '07, when a strange soft noise
> appeared in the front end and detonation began to progress in summer
> '08 during hot weather.
> I still do not know what emits the noise and nobody can help me with
> that. I feel that I'll have to pay Chrysler for a complete diagnostic.
>
> Thank you,
> Val

As I understand, the timing is adjusted automatically based on the
information coming in from the knock sensor, crank sensor, and other
sensors. If one of those sensors is not providing correct information,
the timing is most likely not being adjusted properly for the
condition.

Did you check for codes using an ODBII scan tool, or another
procedure?

Back in the early 1980's, I had a Toyota that was built before all
gasoline went unleaded. It was supposed to be able to run with the
timing set at 5 degrees BTDC. If I tried that, it would pre-detonate,
and would keep running after the ignition was shut off. I had to run
it at TDC, but that really cost in performance.

I am glad that we don't have to mess with timing settings anymore.

-KM