'99 Original SPark Plugs?
Thread Starter
Tech Contributor
Joined: Dec 2006
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From: Van Buren Arkansas
Wounded Warrior Escort '11
'99 Original SPark Plugs?
Does anyone know or remember exactly which spark plug was installed in the '99 Coupe. My manual states the replacement was the platinum 41-931, but I know for sure that isn't the plug that was installed the first time I changed them. I just can't remember what it was. I found a post by C4C5Specialist on the corvettemechanic website that said the 41-952 was used. I've obtained a full set of each, but those 41-952's are a good quarter inch longer than the 931's. I don't need to trash my engine due to the wrong plug. I'm written to ACDelco twice but so far they have not responded. I also contacted Bowling Green but they said they don't keep records that far back and they then suggested the dealer.
I've had pinging issues for a long time and trying my best to get rid of that problem. Yes, I've tried Seafoam twice with essentially no change. No codes at all. Replaced the fuel filter already, no change. I am using the newest recommended 41-985 plugs and I'm wondering if they are too hot for this motor therefore looking at the original plugs. I also have the GM Top End Cleaner but haven't used it pending a formal procedure for its use if anyone knows?
I've had pinging issues for a long time and trying my best to get rid of that problem. Yes, I've tried Seafoam twice with essentially no change. No codes at all. Replaced the fuel filter already, no change. I am using the newest recommended 41-985 plugs and I'm wondering if they are too hot for this motor therefore looking at the original plugs. I also have the GM Top End Cleaner but haven't used it pending a formal procedure for its use if anyone knows?
Thread Starter
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
I did a direct comparison of the 41-985 and the 41-952. They are almost identical in length. Rather than change them in my attempt to solve this pinging issue, I elected to use the GM Top End Cleaner, but rather than letting it sit for 15 minutes, will let it sit 24 hours. I did find an air gap at the Halltech tube to the throttle body on the bottom, sort of hidden from view. I didn't have it on all the way apparently, so that is now on properly. Will fire it up Monday morning and see what happens after it finishes burning off whatever contaminations.
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Does anyone know or remember exactly which spark plug was installed in the '99 Coupe. My manual states the replacement was the platinum 41-931, but I know for sure that isn't the plug that was installed the first time I changed them. I just can't remember what it was. I found a post by C4C5Specialist on the corvettemechanic website that said the 41-952 was used. I've obtained a full set of each, but those 41-952's are a good quarter inch longer than the 931's. I don't need to trash my engine due to the wrong plug. I'm written to ACDelco twice but so far they have not responded. I also contacted Bowling Green but they said they don't keep records that far back and they then suggested the dealer.
I've had pinging issues for a long time and trying my best to get rid of that problem. Yes, I've tried Seafoam twice with essentially no change. No codes at all. Replaced the fuel filter already, no change. I am using the newest recommended 41-985 plugs and I'm wondering if they are too hot for this motor therefore looking at the original plugs. I also have the GM Top End Cleaner but haven't used it pending a formal procedure for its use if anyone knows?
I've had pinging issues for a long time and trying my best to get rid of that problem. Yes, I've tried Seafoam twice with essentially no change. No codes at all. Replaced the fuel filter already, no change. I am using the newest recommended 41-985 plugs and I'm wondering if they are too hot for this motor therefore looking at the original plugs. I also have the GM Top End Cleaner but haven't used it pending a formal procedure for its use if anyone knows?
Race Director
Joined: Oct 2004
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From: Retired but working
Cruise-In VI Veteran
41-985 vs. 41-952 I believe they are the same length, the only diff (told to me by a Vette Mech) is that the 952's were Platinum and the 985's are Iridium.
I had the 952's installed 383 LPE annd just bought the 985's. could not find the 952's.
Regards,
The Pup
I had the 952's installed 383 LPE annd just bought the 985's. could not find the 952's.
Regards,
The Pup
Safety Car
Joined: Aug 2000
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From: San Rafael CA
Use 41-985
The recommended plug for ALL LSx engines in the C5 is the AC Delco 41-985. It is an Iridium tipped plug and it replaces the Platinum plugs originally installed in the engine.
Note these plugs come CORRECTLY pre-gapped at .040 so ignore the gap specified in your owner's manual as that applies to the earlier plugs.
If you want to be certain .. go here and specify your year/model of car and check what AC Delco lists for the car ....
http://www.acdelco.com/index.jsp
Select PARTS CATALOG from the Uppeer banner, then AUTOMOTIVE PARTS SEARCH ....
Note these plugs come CORRECTLY pre-gapped at .040 so ignore the gap specified in your owner's manual as that applies to the earlier plugs.
If you want to be certain .. go here and specify your year/model of car and check what AC Delco lists for the car ....
http://www.acdelco.com/index.jsp
Select PARTS CATALOG from the Uppeer banner, then AUTOMOTIVE PARTS SEARCH ....
