Did I buy the wrong spark plugs?
Thread Starter
Racer
Joined: Aug 2019
Posts: 289
Likes: 64
From: Edinburgh, Scotland
Did I buy the wrong spark plugs?
1999 C5
I had read on the forum (somewhere) these standard copper core NGK’s are fine. NGK 2223/BPR5EFS. GM manual says (0.60) 1.5 mm plug gap, but i now see these are 1.0mm (0.40)
The plugs this NGK chart lists for C5's seem to all be 1.5mm gap.
https://www.ngksparkplugs.co.za/wp-c...logue-2019.pdf
I’m confused, so wonder if those BPR5EFS plugs are actually ok
Seems like Iridium are now generally 0.40 gap but maybe standard copper core should be wider?
I’ve had a slight misfire at idle with no fault codes. Car seems to rev and pull fine when driving. I’ve removed the plugs today and they all look the same, and ok. My ignition leads test ok. Plugs maybe a little bit white on the ends but i don't think anything of concern.
Any input on these particular plugs would be good, thanks
I had read on the forum (somewhere) these standard copper core NGK’s are fine. NGK 2223/BPR5EFS. GM manual says (0.60) 1.5 mm plug gap, but i now see these are 1.0mm (0.40)
The plugs this NGK chart lists for C5's seem to all be 1.5mm gap.
https://www.ngksparkplugs.co.za/wp-c...logue-2019.pdf
I’m confused, so wonder if those BPR5EFS plugs are actually ok
Seems like Iridium are now generally 0.40 gap but maybe standard copper core should be wider?
I’ve had a slight misfire at idle with no fault codes. Car seems to rev and pull fine when driving. I’ve removed the plugs today and they all look the same, and ok. My ignition leads test ok. Plugs maybe a little bit white on the ends but i don't think anything of concern.
Any input on these particular plugs would be good, thanks
Last edited by silver50; Oct 16, 2020 at 01:50 PM.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
In my honest opinion, you cant go wrong with the standard Iridium AC Delco plugs on a stock OEM LS engine. NOTE! The iridium plug does NOTHING for performance. Neither does the COPPER Plug. It all has to do with plug longevity and plug performance. If you had a very high performance fire breathing engine, SURE, there are plugs that preform better under those conditions ( ie Those Copper Core plugs) However, those plugs require being change a lot more frequently. The iridium plugs were installed to allow the engine to be able to meet the government emissions standards for the (if I remember correctly) 80,000 mile requirement.
The 0.040" Gap is fine.
NOTE! When I have a misfire, here is where I start troubleshooting:
- Make SURE that the coil wire is fully seated into the coil. There is a POSITIVE click that has to be made and the boot goes pretty far up on to the coil HT connector. Trapped air can and will prevent it from seating and they can pop back off. I insert a small thin zip tie into the coil wire end of the boot, install the wire on the coil and then use the zip tie to BURP the air out of the boot. Then remove the zip tie. NO MORE AIR in the boot.
- Make sure that the Plug wire is fully seated onto the plug. Again, there is a positive click for that too.
- Broken cracked spark plug. As careful as I am, I have cracked the porcelain insulator. You have to carefully inspect the insulator and make sure it is not cracked.
_ Plug Wire condition and quality. What wires did you use? What plug wire resistance are you seeing on each wire???
You can NOT beat the AC Delco, Performance Red Wires. They fit, form and function perfectly and last a long time. They will not break the bank! These are the wires that I recommend. What ever wires that you have, as long as they are in good working order, they should NOT be the issue.
NOTE, $500 plug wires will not make any more HP than properly functioning $70 Performance Red Wires or the stock OEM black LS1 wires. FACT!
Make sure that the jacket and boots are not damaged.
NOTE A stock AC Delco wire should read approx. 300 ohms to approx. 800 ohms. All wires should be in range The red wires are a spiral wound nickel copper core and are very good for longevity and plug wire performance. Cant comment on what an aftermarket wire should read but, it should NOT be in the MEGOHM range.... Some aftermarket wires have a carbon graphite conductor and have a higher resistance. 1200 -3000 ohms. NOTE, high voltage isn't effected by the plug wire resistance as long as its in the wires designed resistance range.
Bill
The 0.040" Gap is fine.
NOTE! When I have a misfire, here is where I start troubleshooting:
- Make SURE that the coil wire is fully seated into the coil. There is a POSITIVE click that has to be made and the boot goes pretty far up on to the coil HT connector. Trapped air can and will prevent it from seating and they can pop back off. I insert a small thin zip tie into the coil wire end of the boot, install the wire on the coil and then use the zip tie to BURP the air out of the boot. Then remove the zip tie. NO MORE AIR in the boot.
- Make sure that the Plug wire is fully seated onto the plug. Again, there is a positive click for that too.
- Broken cracked spark plug. As careful as I am, I have cracked the porcelain insulator. You have to carefully inspect the insulator and make sure it is not cracked.
_ Plug Wire condition and quality. What wires did you use? What plug wire resistance are you seeing on each wire???
You can NOT beat the AC Delco, Performance Red Wires. They fit, form and function perfectly and last a long time. They will not break the bank! These are the wires that I recommend. What ever wires that you have, as long as they are in good working order, they should NOT be the issue.
NOTE, $500 plug wires will not make any more HP than properly functioning $70 Performance Red Wires or the stock OEM black LS1 wires. FACT!
Make sure that the jacket and boots are not damaged.
NOTE A stock AC Delco wire should read approx. 300 ohms to approx. 800 ohms. All wires should be in range The red wires are a spiral wound nickel copper core and are very good for longevity and plug wire performance. Cant comment on what an aftermarket wire should read but, it should NOT be in the MEGOHM range.... Some aftermarket wires have a carbon graphite conductor and have a higher resistance. 1200 -3000 ohms. NOTE, high voltage isn't effected by the plug wire resistance as long as its in the wires designed resistance range.
Bill
Thread Starter
Racer
Joined: Aug 2019
Posts: 289
Likes: 64
From: Edinburgh, Scotland
In my honest opinion, you cant go wrong with the standard Iridium AC Delco plugs on a stock OEM LS engine. NOTE! The iridium plug does NOTHING for performance. Neither does the COPPER Plug. It all has to do with plug longevity and plug performance. If you had a very high performance fire breathing engine, SURE, there are plugs that preform better under those conditions ( ie Those Copper Core plugs) However, those plugs require being change a lot more frequently. The iridium plugs were installed to allow the engine to be able to meet the government emissions standards for the (if I remember correctly) 80,000 mile requirement.
The 0.040" Gap is fine.
NOTE! When I have a misfire, here is where I start troubleshooting:
- Make SURE that the coil wire is fully seated into the coil. There is a POSITIVE click that has to be made and the boot goes pretty far up on to the coil HT connector. Trapped air can and will prevent it from seating and they can pop back off. I insert a small thin zip tie into the coil wire end of the boot, install the wire on the coil and then use the zip tie to BURP the air out of the boot. Then remove the zip tie. NO MORE AIR in the boot.
- Make sure that the Plug wire is fully seated onto the plug. Again, there is a positive click for that too.
- Broken cracked spark plug. As careful as I am, I have cracked the porcelain insulator. You have to carefully inspect the insulator and make sure it is not cracked.
_ Plug Wire condition and quality. What wires did you use? What plug wire resistance are you seeing on each wire???
You can NOT beat the AC Delco, Performance Red Wires. They fit, form and function perfectly and last a long time. They will not break the bank! These are the wires that I recommend. What ever wires that you have, as long as they are in good working order, they should NOT be the issue.
NOTE, $500 plug wires will not make any more HP than properly functioning $70 Performance Red Wires or the stock OEM black LS1 wires. FACT!
Make sure that the jacket and boots are not damaged.
NOTE A stock AC Delco wire should read approx. 300 ohms to approx. 800 ohms. All wires should be in range The red wires are a spiral wound nickel copper core and are very good for longevity and plug wire performance. Cant comment on what an aftermarket wire should read but, it should NOT be in the MEGOHM range.... Some aftermarket wires have a carbon graphite conductor and have a higher resistance. 1200 -3000 ohms. NOTE, high voltage isn't effected by the plug wire resistance as long as its in the wires designed resistance range.
Bill
The 0.040" Gap is fine.
NOTE! When I have a misfire, here is where I start troubleshooting:
- Make SURE that the coil wire is fully seated into the coil. There is a POSITIVE click that has to be made and the boot goes pretty far up on to the coil HT connector. Trapped air can and will prevent it from seating and they can pop back off. I insert a small thin zip tie into the coil wire end of the boot, install the wire on the coil and then use the zip tie to BURP the air out of the boot. Then remove the zip tie. NO MORE AIR in the boot.
- Make sure that the Plug wire is fully seated onto the plug. Again, there is a positive click for that too.
- Broken cracked spark plug. As careful as I am, I have cracked the porcelain insulator. You have to carefully inspect the insulator and make sure it is not cracked.
_ Plug Wire condition and quality. What wires did you use? What plug wire resistance are you seeing on each wire???
You can NOT beat the AC Delco, Performance Red Wires. They fit, form and function perfectly and last a long time. They will not break the bank! These are the wires that I recommend. What ever wires that you have, as long as they are in good working order, they should NOT be the issue.
NOTE, $500 plug wires will not make any more HP than properly functioning $70 Performance Red Wires or the stock OEM black LS1 wires. FACT!
Make sure that the jacket and boots are not damaged.
NOTE A stock AC Delco wire should read approx. 300 ohms to approx. 800 ohms. All wires should be in range The red wires are a spiral wound nickel copper core and are very good for longevity and plug wire performance. Cant comment on what an aftermarket wire should read but, it should NOT be in the MEGOHM range.... Some aftermarket wires have a carbon graphite conductor and have a higher resistance. 1200 -3000 ohms. NOTE, high voltage isn't effected by the plug wire resistance as long as its in the wires designed resistance range.
Bill
Thoroughly checked seating of the wires before, top and bottom. Did a black out look at the engine when running to look for any stray sparks going to ground but there were none.
I pulled those plugs today to look at them and I they look ok. One was maybe slightly smaller gapped (I assume I must have knocked or dropped it).
I bought new thicker wires (rock auto performance of some sort) but I am still to fit them. I want to be sure the plugs are right first so as not pulling at wires again unnecessarily to take them off. I tested my existing leads a few weeks ago. Can't remember exact readings but all were looking the same so I imagine they're ok. I'd like to get the new leads on when sure about spark plugs.
I have been wondering about ultrasonic injector cleaning and testing (being that my car sat for a long time) but I could be spending unnecessarily and wasting money.
Last edited by silver50; Oct 16, 2020 at 02:06 PM.
Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 595
From: Prescott, Arizona
Thread Starter
Racer
Joined: Aug 2019
Posts: 289
Likes: 64
From: Edinburgh, Scotland
Thanks for posting that. The long and short (or smaller and larger gap..) of that seems a bit like Iridium should be 0.40 so maybe less the case for standard copper core
Due to the different tip design, the gap of the spark plug has also changed. The new spark plug, P/N 12571164 with AC Delco P/N 41-985, is gapped to 1.01mm (0.040 inches) when the spark plug is made
As much as anything I’m wondering if those particular NGK’s I bought should be ok. Even though I read in here they were, I’m not so sure because they don’t seem to be an application for many (or any) cars. I trawled the list above and didn’t see them.
Due to the different tip design, the gap of the spark plug has also changed. The new spark plug, P/N 12571164 with AC Delco P/N 41-985, is gapped to 1.01mm (0.040 inches) when the spark plug is made
As much as anything I’m wondering if those particular NGK’s I bought should be ok. Even though I read in here they were, I’m not so sure because they don’t seem to be an application for many (or any) cars. I trawled the list above and didn’t see them.
