Re: Rotor Gouging Cap

#1

Sean wrote:

Quote:

I have a 92 Caprice with 305 engine and I have a very strange problem.
It seems that the rotor tip is lightly hitting the contacts on the
distributor cap causing gouging of the contacts. It happens on ALL the
contacts but is worse on some.

Are you sure that what you are seeing is the rotor "gouging" the cap
contacts? Every cap that I've ever seen with some miles on it, will
have indents in the contact area....this is normal wear from the spark.
Same thing happens with spark plugs, the metal electrode gets worn.

Time for a new cap and rotor if this is all that is happening.

Ian

#2

On Sun, 22 Aug 2004 22:00:14 +0000, shiden_Kai wrote:

Quote:

Sean wrote:

I have a 92 Caprice with 305 engine and I have a very strange problem.
It seems that the rotor tip is lightly hitting the contacts on the
distributor cap causing gouging of the contacts. It happens on ALL the
contacts but is worse on some.

Are you sure that what you are seeing is the rotor "gouging" the cap
contacts? Every cap that I've ever seen with some miles on it, will
have indents in the contact area....this is normal wear from the spark.
Same thing happens with spark plugs, the metal electrode gets worn.

Time for a new cap and rotor if this is all that is happening.

Ian

It's happening with a new cap and rotor and I even went out and got a
different brand cap and rotor to make certain.
Also if you put your hand on top of the cap while the car is running, you
can actually feel it.

#3

Can you see anything that might be keeping the rotor from being fully
seated?

I assume that you have checked to ensure that the locating tab on the cap is
in the slot for it?

"Sean" <not.givens (AT) spam_not2018 (DOT) org> wrote

Quote:

On Sun, 22 Aug 2004 22:00:14 +0000, shiden_Kai wrote:

Sean wrote:

I have a 92 Caprice with 305 engine and I have a very strange problem.
It seems that the rotor tip is lightly hitting the contacts on the
distributor cap causing gouging of the contacts. It happens on ALL the
contacts but is worse on some.

Are you sure that what you are seeing is the rotor "gouging" the cap
contacts? Every cap that I've ever seen with some miles on it, will
have indents in the contact area....this is normal wear from the spark.
Same thing happens with spark plugs, the metal electrode gets worn.

Time for a new cap and rotor if this is all that is happening.

Ian

It's happening with a new cap and rotor and I even went out and got a
different brand cap and rotor to make certain.
Also if you put your hand on top of the cap while the car is running, you
can actually feel it.

#4

Just out of curiosity when did you first notice this phenomenon and what
brought it to your attention? Can you point to a particular time frame
before which there was no problem and after which there was? What if
anything was being done to your machine during this time frame?

"Sean" <not.givens (AT) spam_not2018 (DOT) org> wrote

Quote:

On Sun, 22 Aug 2004 22:32:09 +0000, Silver Surfer wrote:

Can you see anything that might be keeping the rotor from being fully
seated?

I assume that you have checked to ensure that the locating tab on the
cap is
in the slot for it?

Everything looks pretty good.
After 340,000 on the motor I've become quite good at it

It's really very strange as I would expect to see some play in the shaft
and I do not.

#5

This might just be normal wear in the distributor ... I think you said it
had 350K on it. Try moving the shaft up & down in the dist housing, there
shouldn't be much slop. The contacts in the old cap may have been worn down
slowly over time & the interference is only now showing up with the new cap.
This 'may' affect your engines' timing. Get a replacement dist at the
wreckers with less miles, check the part number in the casting & get the
same one.
"Sean" <not.givens (AT) spam_not2018 (DOT) org> wrote

Quote:

On Mon, 23 Aug 2004 01:04:57 +0000, Silver Surfer wrote:

Just out of curiosity when did you first notice this phenomenon and what
brought it to your attention? Can you point to a particular time frame
before which there was no problem and after which there was? What if
anything was being done to your machine during this time frame?

I just replaced the cap and rotor today with the same brand I have always
been using.
When I started the car I heard whatt sounded like a ticking valve, or an
injector making noise.
I put my hand on the cap and I could feel a slight knock which
corrosponded to the noise.
I turned off the engine, removed the cap and rotor and sure enough I could
see a very, very light scape mark on the caps electrodes. A little more on
one side of the cap than the other.

Thinking I didn't have the rotor/cap seated I tried again with same
results.
Just for kicks I tried a different brand cap and rotor I had laying around
and had the same thing.

If I put my hand on top of the cap and gently flexed it to one side or the
other (you can barely feel it move at all), witht he car running I could
make the sound change.

I took a look at the old cap and the electrodes had deep grooves in them,
yet I don't recall hearing any sound.

Hmmm.... That's odd...

Turns out, I play with the wires on the cap, just twisting them a little
while the car is running and the SOUND GOES AWAY!!!

Possible arcing noise due to positioning of the wires?

Even if so, why the mark which to me looks like a slight scrape not the
normal mark?

It's all very strange but I think it is fixed.

#6

Went back and reread your original post. It's hard for me to envision how a
distributor shaft could get bent, but would that not cause the problem you
are experiencing (or were experiencing)? If the shaft is bent the end of
the rotor would have a slight orbit and likely contact all of the high
voltage contacts inside the cap. You should also see a circular wear patter
on the rotor button as well assuming that it has had enough action to show
wear.

"Mike Atkins" <mikeatkins (AT) sympatico (DOT) ca> wrote

Quote:

This might just be normal wear in the distributor ... I think you said it
had 350K on it. Try moving the shaft up & down in the dist housing, there
shouldn't be much slop. The contacts in the old cap may have been worn
down
slowly over time & the interference is only now showing up with the new
cap.
This 'may' affect your engines' timing. Get a replacement dist at the
wreckers with less miles, check the part number in the casting & get the
same one.
"Sean" <not.givens (AT) spam_not2018 (DOT) org> wrote in message
news:2ot0isFe1nqdU1 (AT) uni-berlin (DOT) de...
On Mon, 23 Aug 2004 01:04:57 +0000, Silver Surfer wrote:

Just out of curiosity when did you first notice this phenomenon and
what
brought it to your attention? Can you point to a particular time
frame
before which there was no problem and after which there was? What if
anything was being done to your machine during this time frame?

I just replaced the cap and rotor today with the same brand I have
always
been using.
When I started the car I heard whatt sounded like a ticking valve, or an
injector making noise.
I put my hand on the cap and I could feel a slight knock which
corrosponded to the noise.
I turned off the engine, removed the cap and rotor and sure enough I
could
see a very, very light scape mark on the caps electrodes. A little more
on
one side of the cap than the other.

Thinking I didn't have the rotor/cap seated I tried again with same
results.
Just for kicks I tried a different brand cap and rotor I had laying
around
and had the same thing.

If I put my hand on top of the cap and gently flexed it to one side or
the
other (you can barely feel it move at all), witht he car running I could
make the sound change.

I took a look at the old cap and the electrodes had deep grooves in
them,
yet I don't recall hearing any sound.

Hmmm.... That's odd...

Turns out, I play with the wires on the cap, just twisting them a little
while the car is running and the SOUND GOES AWAY!!!

Possible arcing noise due to positioning of the wires?

Even if so, why the mark which to me looks like a slight scrape not the
normal mark?

It's all very strange but I think it is fixed.

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Re: Rotor Gouging Cap

General Motors Discussions About General Motors vehicles (alt.autos.gm)

Re: Rotor Gouging Cap - 08-22-2004 , 05:00 PM

Re: Rotor Gouging Cap - 08-22-2004 , 05:06 PM

Re: Rotor Gouging Cap - 08-22-2004 , 05:32 PM

Re: Rotor Gouging Cap - 08-22-2004 , 08:04 PM

Re: Rotor Gouging Cap - 08-23-2004 , 02:29 PM

Re: Rotor Gouging Cap - 08-23-2004 , 07:26 PM