New spark plugs - fixed several problems
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Le Mans Master
Joined: Jan 2000
Posts: 5,075
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From: Poway CA
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New spark plugs - fixed several problems
I had been running NGK TR-55 copper plugs. At about 12k miles, I started to notice the exhaust smell had changed. Not in a way easy to describe. At first I blamed a bad tank of gas, but it persisted over several fillups. Next I started to notice a miss on one cyclinder when cold, as well as some pinging under WOT.
I put in new TR-55-IX Iridium plugs and now the idle is smooth as glass and the exhaust immediately returned to it's normal smell. I went on a 'test ride' with several WOT runs through the gears and not a single ping. No, I'm not claiming the Iridium fixed my problems!
The gap on the used (12k miles) TR-55's had grown to around .065. I gapped them myself to .055 when I installed them. Other than that the plugs looked OK, so I probably could have just re-gapped them, but I already ordered the IX plugs and figure they will last longer then 12k miles without regap.
So a heads-up to you guys running regular copper TR-55's -- You need to check and regap those plugs in as little as 10k miles.
I put in new TR-55-IX Iridium plugs and now the idle is smooth as glass and the exhaust immediately returned to it's normal smell. I went on a 'test ride' with several WOT runs through the gears and not a single ping. No, I'm not claiming the Iridium fixed my problems!
The gap on the used (12k miles) TR-55's had grown to around .065. I gapped them myself to .055 when I installed them. Other than that the plugs looked OK, so I probably could have just re-gapped them, but I already ordered the IX plugs and figure they will last longer then 12k miles without regap.
So a heads-up to you guys running regular copper TR-55's -- You need to check and regap those plugs in as little as 10k miles.
Last edited by SDVette; Sep 5, 2004 at 12:41 AM.
Melting Slicks
Joined: Aug 2000
Posts: 2,900
Likes: 2
From: Green Cove Springs FL
The NGK Iridium plugs I put in my vette lasted only 15k mi. When I pulled them out the electrode was worn down to a stub. I replaced them with copper TR55's expecting to change them out at 10-15k mi, too!
Burning Brakes
Joined: Dec 2000
Posts: 993
Likes: 5
From: Cincinnati Ohio
I replaced the original Delco plugs in my 1999 C5 coupe at 30,000 miles with new Delco plugs (before the updated plugs were released). The new plugs made a significant difference in idle quality and low end "feel". I can't believe Chevrolet recommends up to a 100,000 miles change interval.
