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2000 Seville SLS
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33 Posts
Discussion Starter #1
I just purchased a 2000 Seville SLS with 91,000 miles on it about 2 months ago.

Its ran good, despite smelling a bit rich. A week ago, I was backing out of my steep driveway and I bottomed out and dented the corner of the catalytic converter and created an exhaust leak in the flange connecting the rear exhaust manifold to the downpipe.

Despite the dent and exhaust leak the car was running the same. This morning I drove about 3 miles then the check engine started to flash, I pulled over, noticed the car was shaking a bit. Being late for work I decided to take my chances and drive it.

About a mile later the check engine light went away, but would return when I would accelerate at a low speed. At speeds above 40 the car drove perfectly normal, lower than 40 it would shake a bit, and shake alot at idle, then shake even more accelerating from idle.

Made it to work, got code p0300, cleared the code, drove it after work and code immediatly came back

I've read plenty about the p0300 code in cadillacs, but got my wires crossed after reading a few people suggesting changing the catalytic converter, which leads me to my question. Could me denting my catalytic converter cause this problem? I also read it could be the ignition boots or ICM, is there a way of testing these parts before spewing out money.....
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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19,273 Posts
I just purchased a 2000 Seville SLS with 91,000 miles on it about 2 months ago.

Its ran good, despite smelling a bit rich. A week ago, I was backing out of my steep driveway and I bottomed out and dented the corner of the catalytic converter and created an exhaust leak in the flange connecting the rear exhaust manifold to the downpipe.

Despite the dent and exhaust leak the car was running the same. This morning I drove about 3 miles then the check engine started to flash, I pulled over, noticed the car was shaking a bit. Being late for work I decided to take my chances and drive it.

About a mile later the check engine light went away, but would return when I would accelerate at a low speed. At speeds above 40 the car drove perfectly normal, lower than 40 it would shake a bit, and shake alot at idle, then shake even more accelerating from idle.

Made it to work, got code p0300, cleared the code, drove it after work and code immediatly came back

I've read plenty about the p0300 code in cadillacs, but got my wires crossed after reading a few people suggesting changing the catalytic converter, which leads me to my question. Could me denting my catalytic converter cause this problem? I also read it could be the ignition boots or ICM, is there a way of testing these parts before spewing out money.....
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P0300 is a generic misfire code -
our on-board code readers will not display WHICH cylinder/cylinders is/are misfiring -
only that there IS a misfire -

take the car to any large auto parts store - they will check your codes for free -

P0301 is a misfire in cylinder #1 - P0302 is cylinder #2 - P0303 is #3 - etc -

once you discover WHICH cylinder is misfiring - diagnosis becomes much easier -
 

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2000 Seville SLS
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33 Posts
Discussion Starter #3
Thanks alot for the reply, didnt realize I could specify the cylinder with a reader.....I have a friend with a code reader, will check him out tomorrow and plug that thing up...
 

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02 Seville, 04 SRX
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1,341 Posts
If you end up having to buy a new cassette, the one on RockAuto that is ~$100, is manufactured by Denso and I think they were the same company that built the original. The "OEM" one costs a lot more.
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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19,273 Posts
If you end up having to buy a new cassette, the one on RockAuto that is ~$100, is manufactured by Denso and I think they were the same company that built the original. The "OEM" one costs a lot more.
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don's see any for $100 -
the cheapest one is $152+10 shipping -

still not too bad for a new one -
 

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2000 Seville SLS
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33 Posts
Discussion Starter #7
Any way i can test the cassette out? With a multimeter or sonething?

Also i believe Denso is OEM parts for Toyota, Scion, Lexus and Honda. GM OEM parts are usually made by AC Delco and Delphi but there could be some exceptions
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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68,479 Posts
DENSO, Japan makes a BUNCH of OEM GM parts and sensors. (AC Delco Professional Platinum spark plugs and CKP/CMP sensors, for starters.)

Robert Bosch, Germany makes the lion's share of the fuel injection systems.

............. and a lot of the fabric and plastic trim is Canadian or Mexican.

DELPHI is an on-again, off-again division of GM - they did the work with Lord to develop the Magnetic Ride Control systems. AC Delco is a parts-sourcing division: I have two Northstar water pumps on the shelf in the familiar AC Delco boxes. Both pumps have a small gold sticker affixed - "Made in China".

Your original CKPs were made by Siemens in Mexico. They have a near-100% failure rate and the new ones are made by ......... DENSO Japan.

Here's a Seville fuel pump assembly box. Who made the contents ???

For the ignition cassette - you would need an internal wiring schematic, remove the ICM, and check the coil primaries for proper resistance. Coil secondary to ground resistance, too. The ICM in the cassette is retained by two screws and two snap clips molded into the plastic. That connector, which few even know is there, can develop moisture in the seal boot, leading to short circuits in the coil trigger pulses.
 

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Super Moderator
White Diamond '03 DHS (with DTS floor shift)
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86,785 Posts
Any way i can test the cassette out? With a multimeter or sonething?
You COULD remove the cassette and set it aside. Then run a set of spark plug cables in place of the springs & boots shown in the above post #9. Then you could use a timing light to see which coil is failing. It's a bit Rube Goldberg, but probably the easiest way to test the ignition cassette coils.
 

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2000 Seville SLS
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33 Posts
Discussion Starter #12
So I pulled my plugs today to see what was going on, all of them were white and coroded looking.

While pulling the plugs i discovered the culprit, the plug in the front and in the rear farthest to the driver side were drenched in oil....

at first i thought it was the valvs cover gasket until i noticed its the front AND the rear.

Any ideas as to where the leak could be coming from?
 

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2000 Seville SLS
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33 Posts
Discussion Starter #13
Just finished changing the plugs. Took it for a test drive and its still shaking, still throwing p0300, and the check oil light came on

Brought it home and checked the oil and its barely registering on the dipstick. It also smells loke burnt oil under the hood... The check oil light came on yesterday too and i dumped 2 quarts in it.

Looks like im dealing with an oil leak..
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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19,273 Posts
So I pulled my plugs today to see what was going on, all of them were white and coroded looking.

While pulling the plugs i discovered the culprit, the plug in the front and in the rear farthest to the driver side were drenched in oil....
================================
While pulling the plugs i discovered the culprit,
the plug in the front and in the rear farthest to the driver side
were drenched in oil....

that is NOT uncommon - and NOT the culprit -

there are "O" rings in the cam covers that quite often seep/leak -
over time - the oil can collect around the spark plugs -
oil is non-conductive - and will not cause a plug to misfire -

re-read post #2 -
discover which cylinder/cylinders is/are misfiring -
and report back with your findings -

=========================

The check oil light came on yesterday too
and i dumped 2 quarts in it

the CHECK OIL LEVEL warning
will appear when you are about 2 quarts low -

check the rear cam cover gasket -
a fairly common leak -

the oil pressure switch is also a common source of oil leak -
along with the oil filter adapter "O" rings -
 

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Super Moderator
White Diamond '03 DHS (with DTS floor shift)
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86,785 Posts
Yeah, don't sweat the oil in the plug wells. we all have it.

I suspect a bad coil, which means figure out which bank and replace that cassette.
 

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2000 Seville SLS
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33 Posts
Discussion Starter #16
Thank you for all of your guy's help I greatly appreciate it. I head over to my buddys house today and get that code reader then report back.
 

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Cadillac 2000 SLS, 2008 Shelby GT500 Convertible, 67 Shelby Clone, 2016 Mercedes C300
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138 Posts
Just an Fyi, if you need a cassette in a hurry you can get from Advance. Search for their 30% coupon online and place an order to pickup in their local store. I got one for about $150 local. It's been working fine for 20,000+ miles so far.
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
Joined
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19,273 Posts
Just an Fyi, if you need a cassette in a hurry you can get from Advance. Search for their 30% coupon online and place an order to pickup in their local store. I got one for about $150 local. It's been working fine for 20,000+ miles so far.
===========================
and if you can wait a couple days for shipping -
here is a new one for $85.95 - including shipping -
http://www.ebay.com/itm/Ignition-Coil-Pack-Driver-Side-Left-LH-NEW-For-Aurora-Deville-Seville-Eldorado-/131027979504?pt=Motors_Car_Truck_Parts_Accessories&fits=Year:2002|Model:DeVille&hash=item1e81e04cf0&vxp=mtr
 

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2000 Seville SLS
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33 Posts
Discussion Starter #19
Unfortunately we dont have advance auto in San Diego. I want to go AC Delco or Delphi because I dont really trust Autozone or Oreilly parts. The problem is I would have to order it but I need my car to get to work everyday. Would it be safe to drive about 30-40 miles a day until the part gets here? Or should I just bite the bullet with an autozone part?
 

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2000 Seville SLS
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33 Posts
Discussion Starter #20
Finally ran the codes. The misfire is in cylinder 7... would that be the front or the back cassette?
 
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