JasonA Posted January 10, 2006 Report Share Posted January 10, 2006 Northstar owners: what does the underhood sticker indicate for a spark plug gap on your Northstar car, be it a Seville, Eldorado, or DeVille. I ask this only of 93-99 owners, because the ignition system changed drastically in 2000. I ask because my car seems to be the only one that calls for a gap of .060" for some reason, as confirmed on my underhood sticker. Most others indicate .050". Even if you were part of the discussion in the other "New Spark Plugs" thread, please reply here. I want to gather a comprehensive survey to try to understand what the real deal is. Quote Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
JimD Posted January 10, 2006 Report Share Posted January 10, 2006 '98 Seville; underhood sticker says nothing about spark plugs. Owner's Manual says nothing about spark plug gap. Quote Jim Drive your car. Use your cell phone. CHOOSE ONE ! Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 10, 2006 Report Share Posted January 10, 2006 (edited) 96 Deville .050 6'5" 230 pounds, black hair, brown eyes Here is a picture from the sticker located in the center of the hood when you look up near the latch/lock mechanism. Edited January 10, 2006 by BodybyFisher Quote Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
jackc Posted January 11, 2006 Report Share Posted January 11, 2006 93 300 hp - sticker says .050 Quote Link to comment Share on other sites More sharing options...
JohnnyG Posted January 11, 2006 Report Share Posted January 11, 2006 The sticker under the hood of my '99 says nothing about plug gap. It tells me what coolant to use, and to add the sealant tabs (3), and what the colors of the different "gizmos" mean (fluids), but no plug gap info. Another sticker, way back under the hood and attached to it, tells about vacuum hose routing and the major component layout, but no plug gap info there either. This is a "9" engine, STS Quote Never underestimate the amount of a persons greed. Link to comment Share on other sites More sharing options...
Ebby Posted January 11, 2006 Report Share Posted January 11, 2006 97 STS pulled old plugs out #41-950 checked gap .060" Just looked all through both Factory Services Manuals for 97 and could not find a chart giving the spark plug gap. I set the new ones at .050" ? and tightened to 132 in lb Quote Link to comment Share on other sites More sharing options...
Ebby Posted January 12, 2006 Report Share Posted January 12, 2006 Jason I had a chance today to call the local Caddy dealer to ask them what the gap should be for my car and the guy had a hard time finding it. He told me he would call back when he found out. He called back and said he looked under the hood of a 99 in the shop and it had no sticker so he looked it up in the GM comp. and told me .050". He also told me not to worry as the gaps are set at the factory ? I told him I like to double check just in case one or more were off. Are you having any luck getting to the bottom of this as to why there seems to be two gaps for the same year? Quote Link to comment Share on other sites More sharing options...
JasonA Posted January 13, 2006 Author Report Share Posted January 13, 2006 Are you having any luck getting to the bottom of this as to why there seems to be two gaps for the same year? Actually, yes. I received this answer from a "reputable source": The spark plug manufacturer and supplier has changed several times. The gap changed a little with the specifics of the spark plug supplier and their production process as I recall. Either .050 or .060 is really OK....not that big of a deal with that type of plug. .060 is the better gap as (generally speaking) the larger the gap the greater the arc and the greater the chance of contacting something combustable and starting ignition. If there is any doubt about the longevity of the platinum pads (as you noted) then the desire might be to run .050 so as to not have too great of a gap at .070 (which is starting to push the capability of the ignition system). As the platinum pad retention improved and the plug quality and process control improved over the years the gap could be allowed to creep up. Based on this answer, I'll definitely keep my new plugs at .060". Thanks everyone for their contribution to this thread. Quote Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 13, 2006 Report Share Posted January 13, 2006 I went to the dealer and found out that the gap for the 97 is .060, three techs and the parts department confirmed it.. Asked why that year is .060, and other years are .050, no one knew the answer, nor could they understand why AC Delco, Champion and Autolite's web site states .050.... Personally, I would use .050 and see how she starts and runs due to all of the reading we did regarding high compression engines and due to what Britt said, but if you are happy with .060, terrific. For some reason, I can't help but think this is a mistake (.060), because NO ONE can explain why all other years are .050.. This would bug me Quote Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
JasonA Posted January 13, 2006 Author Report Share Posted January 13, 2006 For some reason, I can't help but think this is a mistake (.060), because NO ONE can explain why all other years are .050.. This would bug me The explanation is above. I used to wonder why, but now I know. We have trusted in this source before, no reason to change now. Quote Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 13, 2006 Report Share Posted January 13, 2006 I figured that your source was impeachable... Quote Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Spurlee Posted January 13, 2006 Report Share Posted January 13, 2006 I checked this morning, my '96 El Dorado calls for 0.50 on the sticker under the hood. Quote Scott 1996 El Dorado 2006 STS 2000 Corvette Link to comment Share on other sites More sharing options...
JasonA Posted January 14, 2006 Author Report Share Posted January 14, 2006 I figured that your source was impeachable... It's nothing short of legendary. Quote Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 14, 2006 Report Share Posted January 14, 2006 Actually re-reading my post, I meant UN-impeachable.... Quote Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Terrence Mayes Posted April 6, 2020 Report Share Posted April 6, 2020 On 1/10/2006 at 9:17 PM, Ebby said: 97 STS pulled old plugs out #41-950 checked gap .060" Just looked all through both Factory Services Manuals for 97 and could not find a chart giving the spark plug gap. I set the new ones at .050" ? and tightened to 132 in lb Was it better at .50? Quote Link to comment Share on other sites More sharing options...
BodybyFisher Posted April 6, 2020 Report Share Posted April 6, 2020 I would go with what the recommended gap is on the under hood label. I think the .060 was an aberration. The 1996 factory service manual states the gap as .050 in regardless of engine variation, see photo Quote Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
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