Spark Plugs

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218
Location
Cali, USA
Thread starter
Hey guys, My 03 Suburban has 153K on it, unknown whether the plugs have ever been out of it. I did a search of the forum for spark plug topics, none really answered my question. The aforementioned topics referred to service bulletins and specific AC Delco plug numbers for the pre and post '03 - '04 model year. Given a choice, do you stick with ACD, switch to NGK, or go with some other brand? I, personally, like to stick to OEM or name brands that are trusted by the industry, but have been out of the game long enough that I no longer know what brands are acceptable and those that should be shunned like the red headed stepchild of [censored]! grin2
 
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10,251
Location
USA
Many of the ACDelco iridiums are actually made by NGK. Also, NGK makes good wires that are numbered and come in a pretty blue color smile If the spark plugs are difficult to change on your Suburban, you may want to consider iridium or even NGK's new ruthenium, so you never have to do them again!
 
Messages
218
Location
Cali, USA
Thread starter
I am concerned about pulling the existing plugs, as I've heard these engines don't like to give originals up easily after 100k.
 
Messages
218
Location
Cali, USA
Thread starter
Originally Posted by slacktide_bitog
If the spark plugs are difficult to change on your Suburban, you may want to consider iridium or even NGK's new ruthenium, so you never have to do them again!
I don't even want to do them now! crzy grin2 The reasoning behind changing them out is that I feel that MPG is a tad lower than it could/should be, and cold idle is a bit rough. Picking up just 2 or 3 MPG will pay for the plugs within a few tanks. cool
 
Messages
8,311
Location
Texas
Those plugs are SIMPLE to change -you can do plugs and wires in under 2hours taking your time. I have it down to about 45min-1hr. The only difficult one is the back plug on the paassenger side. Bend the AC drain shield a little to make room and use a 1" extension or just get that one plug from underneath. You will spend more time on that plug than the other 3 on that same side lol. Me personally, I have been running Autolite Iridium XP plugs with good results.
 
Messages
4,740
Location
Fort Worth, Texas
I've pulled original plugs out of these past 250K....In a non-corrosive environment, It's not an issue! #8 is fun on a Suburban with rear Heat & A/C! Seat the plug wires on the spark plugs first....Then the coils! Use Delco Iridium plugs & Delco plug wires. Your 'Burb takes 2 different plug wires depending on the Ignition Coils you have......Long ones for Hitachi coils & Short ones for the Delco coils. Most dealers & part stores will sell the long wires regardless making the job look hacked-up if you have Delco coils. LS3 plug wires GM# 19351593 ACD# 748RR fits GMT-800 Delco Coils perfectly! Better than the OE wires even, They are red in color if it matters. WILL NOT fit trucks/SUV's with Hitachi coils.
 
Messages
218
Location
Cali, USA
Thread starter
Originally Posted by clinebarger
I've pulled original plugs out of these past 250K....In a non-corrosive environment, It's not an issue! #8 is fun on a Suburban with rear Heat & A/C! Seat the plug wires on the spark plugs first....Then the coils! Use Delco Iridium plugs & Delco plug wires. Your 'Burb takes 2 different plug wires depending on the Ignition Coils you have......Long ones for Hitachi coils & Short ones for the Delco coils. Most dealers & part stores will sell the long wires regardless making the job look hacked-up if you have Delco coils. LS3 plug wires GM# 19351593 ACD# 748RR fits GMT-800 Delco Coils perfectly! Better than the OE wires even, They are red in color if it matters. WILL NOT fit trucks/SUV's with Hitachi coils.
This is 100% a California truck, so there is little to no corrosion anywhere. In fact, until the last few years, she's been garage kept, so darned near showroom new looking. I've owned her for a year, previous owner was the son-in-law of the original owner, as far as I can tell. A little neglected here and there, but overall very good bones and has responded well to the TLC I've given her over the past year. Baby does indeed have the rear HVAC system, which I was surprised was plumbed all the way from the front instead of a "stand alone" unit. Question for you, should the wires be changed with the plugs? Sorry for the Newb question, but my mechanical knowledge is over 30 years old. Back in the day, you just changed everything out, today seems to take a more surgical approach.
 
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1,414
Location
South Carolina
I just changed the plugs on a 2003 Silverado. It had an old set of ACDelco double platinums in it that had ~115k miles on them. (220k on the engine total) The gaps on them ranged from .035" to .065" with the platinum completely gone from 3 of them. The truck ran ok before with no misfires. I put in new NGK TR55IX plugs gapped at .060", along with new Taylor thundervolt wires, and it runs better now. It idles smoother and seems more responsive. The #8 plug isn't an issue for me. I just use a 3/4" wrench on the end of plug socket. It's out in less than a minute. I've never understood the move to .040" gap. The best guess I have is to just consolidate inventory. I use NGK TR55 plugs at .060" in my 2002 Tahoe.
 
Messages
572
Location
Ohio
I just used autolite irridiums in my 08 impala 3.9 and have no complaints. I did wonder if the originals were installed with an impact though. I was a little worried that I'd be pulling the head trying to get the last one out but it came thank goodness. My GM tech said the autolites work well with GM engines and so far everything seems the same as the oem plugs.
 
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15,226
Location
N.H, U.S.A.
Those autolite Ir plugs look well made and they are not super expensive. Japanese don't have spark engineering cornered That would be Delco-Remy in the 80's From my vast tuneup experience only PACKARD makes good secondary wires. Supplier to Delco Even the many Japanese mfgrs buy the stuff and assemble and terminate overseas Most of my Subaru with Dist or waste spark came with USA Packard wires and Champion spark plugs!
 
Messages
1,414
Location
South Carolina
Originally Posted by BigCahuna
So you have a 17 year old vehicle, with maybe the original plugs in it, that hasn't given you any problems, and want to know which ones to use?. Boy that's a tough one.,,,
There's been a TSB issued on those plugs. When you do a part search, the OEM plugs that came out of that truck don't show up. It shows up a newer plug with a narrower gap. I've seen this cause some confusion when the newer plug says .039" gap when the owner's manual and sticker on the filter box says a different part number and .060" gap. I went through that myself the first time I changed the plugs in my Tahoe.
 

pbm

Messages
8,710
Location
New York
Originally Posted by D1dad
I just used autolite irridiums in my 08 impala 3.9 and have no complaints. I did wonder if the originals were installed with an impact though. I was a little worried that I'd be pulling the head trying to get the last one out but it came thank goodness. My GM tech said the autolites work well with GM engines and so far everything seems the same as the oem plugs.
I normally use OE plugs but I have used Autolite Iridiums in a couple of Ford Duratecs (a 2.0 and a 2.3) with no issues....they seem like good plugs at a good price.
 
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