2000 w/5.3 acts like a dog off the line

rjirvine · January 27, 2007

Question for 2000 NBS Silverado owners with the 5.3 engine: (I think the applicable years is 99-04 but not sure)

Has anyone replaced their spark plugs from the 41-952 stock (PTJ16R15) with the 41-985's and found that you have a power loss? The 985 is the new stock replacement, and the 952's are getting hard to find. I know the stocks are gapped at .060 and the 985's are gapped to .040, and I checked mine before I put them in and they were .040. I seem to have lost a little power, but can't be sure as I replaced the plugs about a week or two after I bought it with 93k miles. The truck starts/idles/runs just fine, but it's really kinda doggy off the line. I have the 4.10 rear end and 265 75R 16 tires. It's been bugging me and I was wondering if I should find a pair of 41-952's and put those back in. I replaced the wires etc when I changed the plugs, fuel filter, press regulator, pump pressure etc are all fine, No codes or anything. I think I may just be imagining things.

I've read on here how its best to stick with AC-Delco plugs for these engines. I think I'll follow that guideline unless I can find a consensus on a better plug. Any thoughts?

Indy · January 27, 2007

All GM trucks are a dog off the line because they have torque management programmed in the computer. This is supposedly to save drive-line components.

Get a custom tune by Wester's, wait4me or others and you can have all or most of this torque management removed. You'll also gain a bunch of HP and or mileage too.

overkill · January 28, 2007

Also, make sure you got all the plug wires back on making full contact. I know the #8 plug is a pain to get to and make sure is snaped on.

ontheedge02 · January 28, 2007

I hear what you are saying. I have an 01 Silverado with the 5.3L and changed out the original plugs with the 41-985s and experienced this same loss of power. I drove it for a few days, thinking that the comptuer would adjust for the change and the power would come back. Well it didn't, so I went and bought some NGK TR55 at $1.69 each and thought I would try those. The power came right back, so now I have $40 worth of spark plugs (41-985) sitting on my work bench taking up space. I think I will leave the NGK's in and maybe try the AC Delco's again after 30k miles.

Khaos05 · January 28, 2007

All GM trucks are a dog off the line because they have torque management programmed in the computer. This is supposedly to save drive-line components.
Get a custom tune by Wester's, wait4me or others and you can have all or most of this torque management removed. You'll also gain a bunch of HP and or mileage too.

mine isn't

i've got an 06 sierra z71 with the 5.3L and it'll squeel the tires from a stop...ive only done it once b/c i'm so picky with my truck and i baby it...but it still has some "umph" to it

roundhouse · January 31, 2007

All GM trucks are a dog off the line because they have torque management programmed in the computer. This is supposedly to save drive-line components.
Get a custom tune by Wester's, wait4me or others and you can have all or most of this torque management removed. You'll also gain a bunch of HP and or mileage too.

Does this apply to the 5.7 also?

jdc232 · February 5, 2007

I have the 41-985's in my truck no problems from them at all. If I'm not mistaken the factory plug is a double platinum based plug, and the 41-985 is an iridium based plug, iridium will fire hotter and last longer than platinum. But from my opinion, AC Delco plugs are the best for it, some of the other plugs have shown problems in these engines especially Bosch and other non-platinums. If the plugs are not firing or a wire is loose 9 out of 10 times the OBDII computer system will pick it up and determine which cylinder it is that's not firing. The main question is if the problem started before or after the plugs were changed, if it was after then it is a possibility that the wires you used may have to much resistance to give you the correct amount of fire. When I changed the plugs I also put a new set of AC Delco Wires on it.

svensk · February 5, 2007

My 2000 Sierra 5.3 with 3.73's is a raped ape off the line. I have 265 tires but it will still spin into 2nd gear if I jam on it from a stop. I still have the old delco plats on @ .060 gap and I think I will replace them this spring with NGK. "C&A Dad" was saying good things about them and I will give them a try.

Indy · February 5, 2007

All GM trucks are a dog off the line because they have torque management programmed in the computer. This is supposedly to save drive-line components.
Get a custom tune by Wester's, wait4me or others and you can have all or most of this torque management removed. You'll also gain a bunch of HP and or mileage too.

Does this apply to the 5.7 also?

No, I don't think so.

rjirvine · May 27, 2007

Okay, I can't handle the lack of performance anymore and want to switch to NGK 55 plugs. I see there are tr55 and tr55IX etc. What would you recommend for my 2000 Silv ECSB 4x4 w/ 5.3. Iridium, platinum, or copper cores? Price is not an option, and as I drive 7500 mi a year I really don't have a problem with changeing the plugs every few years. As far as plug wires, I put a set of AC Delco stock in when I switched to the 41-985's.

thecraft · May 27, 2007

All GM trucks are a dog off the line because they have torque management programmed in the computer. This is supposedly to save drive-line components.
Get a custom tune by Wester's, wait4me or others and you can have all or most of this torque management removed. You'll also gain a bunch of HP and or mileage too.

Does this apply to the 5.7 also?

It applies to all 1996 and newer trucks.