spark plugs

I am changing the spark plugs in my truck. I went to Auto Zone and they were trying to sell me the Bosch Fusions. Has anyone tried these plugs out? I remmeber a while ago there was a thread about plugs and Bosch was not at the top of the list.

I stuck with the AcDelco Irridiums but just wondering if anyone used the Fusions. At $8.00 a piece I was scared to just give it a try.

Allright now a second question onto my spark plug thread here.

How often should one check their sparkplug gap? When I changed mine out I checked the gap in the old ones just for kicks. Four of them were at 38 (1-2-4-6). 3-5-8 were 36 and 7 was at 34. I set all new ones at 40 so how long should I wait to check these or do you think this was a mechanic errrer?

Allright now a second question onto my spark plug thread here.

How often should one check their sparkplug gap? When I changed mine out I checked the gap in the old ones just for kicks. Four of them were at 38 (1-2-4-6). 3-5-8 were 36 and 7 was at 34. I set all new ones at 40 so how long should I wait to check these or do you think this was a mechanic errrer?

so you had to set the new plug gap...it was not .040 ? on the ac delcos....did it say they were made in china..?

Allright now a second question onto my spark plug thread here.
How often should one check their sparkplug gap? When I changed mine out I checked the gap in the old ones just for kicks. Four of them were at 38 (1-2-4-6). 3-5-8 were 36 and 7 was at 34. I set all new ones at 40 so how long should I wait to check these or do you think this was a mechanic errrer?
i read something years ago that showed the rat of spark plug gap increase over a period of time. As plugs age the gap tends to get larger due to the normal combustion cycle and erosion. I'm trying to remember what the rate was but it was fairly minimal and the length of time was like 30,000 miles before any noticeable gap increase was recorded. That info may not pertain to newer, modern "long life " plugs but as a "personal rule" I always used to replace my plugs every 12 to 18 months on my older vehicles, and lengthen the time to about 60,000 to 70,000 miles on the "100,000 mile plugs". As a quick test, you could pull a plug or 2 and quickly check the gap to get an idea of what is going on and inspect the condition of the plug at the same time. You can do that quick test any time you think you need to whether it be at 30,000, 50,000 or 70,000 miles. As for mechanic error, it's possible. Either the mechanic didn't check the gap before installing them or was using the gauge incorrectly,( as is possible with some styles of gappers), or a sub-standard spark plug gauge that doesn't display the correct thickness for the required gap.

[quote='97ventureowner]quote]

I find your response exactly the same as my 40years experience with this....

what I have also found is the plugs I have installed come out slightly greater on the gap with the center electrode pointed instead of flat..

when I purchase a new vehicle like every 10-17years I remove all the plugs and check for proper gap, as well as other things..

they do not use great care at the factory....

Pitch the Bosh plugs in the trash can.
Only use the AC-delco plugs the book calls for.

The newer plat Ac delco plugs the gap should be pre set and the good book say not to reset ot try gapping them.
Check gap and if not right pitch them back to the parts man and get some that is.

Some engines ab=nd years the plug no and gap has been changed.
Always check the latest ac-delco plug book.
For right applacation and gap.
GOOD lUCK

pitch bosch AND ac-delco into the trash can. buy HALOs.
1. no gapping.
2. one and only plug proven by government research to improve mpg. if someone tells you that they "run hot" etc, it's just envy's chat. they have them in exactry right specs for any vehicle. they are official Lambo and VW plug for reason.
i, personally, have been running them in my imports and domestics, including my silvie, for yrs.

http://greenplugs.com/LSG%20Halo%20Spark%20Plug%20Test%20Results.pdf

http://www.lsgbrisk.com/

so you had to set the new plug gap...it was not .040 ? on the ac delcos....did it say they were made in china..?

they were all at 40 except one at 38. DOnt think they said china on them but didnt look either

well I thought that over time the gap would get wider also. I know I have a cheap gauge. (one of the key chain ones) So at first I was think 38 was OK but I dont thin that I should have had 3 different gaps come off of my truck. I think it explained the shaky idling. It wasn't bad but I could tell. New plugs now and no more shake

well I thought that over time the gap would get wider also. I know I have a cheap gauge. (one of the key chain ones) So at first I was think 38 was OK but I dont thin that I should have had 3 different gaps come off of my truck. I think it explained the shaky idling. It wasn't bad but I could tell. New plugs now and no more shake

the reason I asked the place of manufacture is because I thought a/c plugs are no longer made in michigan...

the gap guage is most likely accurate ...but be careful when you insert the wire so as to not damage the tip...your findings mean that these plugs were not gaped correctly...it is always good practice to check this prior to install....

the reason I asked the place of manufacture is because I thought a/c plugs are no longer made in michigan...

You're right. GM has outsourced production of these and their filters among other parts to other companies. The oil filters, once rated very highly in an oil filter test done a few years ago ( http://minimopar.knizefamily.net/oilfilterstudy.html )now rank towards the bottom of the list in a similar test done last year as an update to the original test.

the reason I asked the place of manufacture is because I thought a/c plugs are no longer made in michigan...

the gap guage is most likely accurate ...but be careful when you insert the wire so as to not damage the tip...your findings mean that these plugs were not gaped correctly...it is always good practice to check this prior to install....
looked on the box it says detroit Michagan 1995. Wonder where they have been sitting?

looked on the box it says detroit Michagan 1995. Wonder where they have been sitting?
I see that quite a bit, especially if that particular part fits many applications. Sometimes a dealer may sell some of their older inventory in lots to those who resell them in ads featuring OEM parts for older vehicles. Sometimes a warehouse that services the dealers may come across these items on the back of their shelves and ship them out in an order to a dealer as well.

Bosch platinum plugs, and all the varieties, are made such that the center electrode is encircled with the ceramic insulator...only the very tip is the actual Pt/Ir conductor. This makes these plugs impossible to readjust the gap as it erodes down into the insulator, which is about 0.001 for every 2k-3k miles. For the multi-electrode versions, they are impossible to gap. Steer clear of them. The ECM has to adjust greatly to their different spark pattern...usually to the detriment of performance and fuel economy.

I personally have been very pleased with Autolite platinums in all my vehicles. At about $2.90 apiece, they're reasonable and reliable without succumbing to all that +2, +4, super-duper hyper spark crap.

Hype is what I would call it too!!! I think that for the most part, any kind of product that is meant to "boost performance and economy" is just a way to sell product. I think most gains are minimal, and long gone are the days of real performance enhancing products. This is probably a result of better engineering from the manufacturers. As far as gapping, I just checked to see if they were all correct out of the box (Delco Iridiums) and installed them. The harder Iridium is supposed to keep you from having to regap them over the life of the plugs. (which is what, a 100,000 miles?) Ahhh, do you remember the old days of gapping points, checking dwell, changing the cap and rotor and adjusting the carburetor!!! Thank God for computers!!