What is BEST Sark Plugs for 3400 V6

[Bens71442]

What are the absolute BEST Plugs Money can buy, for a 2002 Alero with a 3400 V6?

Installed 2500 miles ago Auto lite Double Platinum APP606

Now experinceing Cold idle rough run.

Rough IDLE completely disappears after 3 to 4 minutes run time

HOT restart no issues what so ever.

Help me please before I drive me and my Alero into Lake St.Clair

[Superdave]

Platinum plugs don't work in these engines. Never have and never will.

the AC-Delco Iridiums are the best you can get.

[AaronGTR]

Well, that really depends on what you have done to the car. There is no one best plug. There is only a best plug for a specific application based on needs of how the engine runs. Is your engine mostly stock? Then I'd say you probably should stick with the stock AC delco platinums or the new iridiums that came in the latest 3400's. They should be stock heat range also. Autolite plugs don't have the best reputation so they may be your problem right there.

[asylummotorsports]

What Superdave said! PERIOD!

[Bens71442]

Wow!

I would have never known that Platinum plugs aren't worth a hill of beans on the 3400 V6

They are coming OUT tomorrow morning as soon as I'm finished with my daily morning internet porn. Just kidding.

I guess I'll go back to the AC Delco Iridiums but I can't stand the price of them.

After I put these Double Platinum Auto lites in there my power gain was very noticeable.

I have done NO modification to this stock 3400 V6 and its not my intention to do so.... just my daily grocery getter vehicle here.

IS there a big enough difference with the Heat range with the plugs I installed?

Auto lite Double platinums APP 606

Is or Are the 3400 V6 engine this susceptable to improper heat range of a spark plug?

Are Auto lite Double platniums that far off to be casing this rough idle cold engine condition?

I'm shocked if these plugs are the cause of this rough run cold. but evidently, all the signs point to the plugs

after they warm up after 3 to 4 minutes run time; idle smooths out perfectly and NO rough run at all.

No rough run after hot soak and restart. No rough run on a warm engine either!!!!!

[AaronGTR]

Well, I don't really agree with that. It's just certain platinum plugs from certain manufacturers in my opinion. I never had problems with the stock platinum plugs in mine and never have thousands of other people with factory plugs in 3400's. They last for 100k miles which is what platinum is for. It's just that iridium is a little better because the smaller tip requires less voltage for the spark to jump.


And yes, any engine can have problems with plugs of the wrong heat range. They are more likely to foul and cause bad idle if they are too cold. For a stock engine, you need plugs in the stock heat range.

[Superdave]

the stock Delco Platinums are better than the Autolites and Bosch plugs, but not by much. Bosch and Autolites are junk, lol.

our waste spark DIS system kills platinum plugs. Iridiums are well worth the money, one set will last longer than your engine.

[andrew383]

the stock Delco Platinums are better than the Autolites and Bosch plugs, but not by much. Bosch and Autolites are junk, lol.

our waste spark DIS system kills platinum plugs. Iridiums are well worth the money, one set will last longer than your engine.

can you give more detail as to why (copper core) autolites are junk?The 97-current W-body guys swear by them.
The stock plug is a 606 rite?Whats the delco part #,and whats the next range colder plug?

[robertisaar]

can you give more detail as to why (copper core) autolites are junk?The 97-current W-body guys swear by them.
The stock plug is a 606 rite?Whats the delco part #,and whats the next range colder plug?

i don't know which w-body forum you're on but on w-body.com, we know that anything other than the ACDelcos are pointless...

[gectek]

ngk makes ACdelco irridium and some others
I like the NGK TR55

[IsaacHayes]

http://60degreev6.com/forum/f86/spark-plug-info-for-pushrod-motors-t37003

Read...

Stock plug as long as it's in good shape will give you most power. You won't gain any power by a different plug, only loose power if they are worn out or the wrong plug.

If you don't want to pay for iridium then get the plain AC delcos at the top of the list on that link for gen3 I posted. that's what I run and they hardly wear much at all.

[mfewtrail]

Autolites are junk, lol.

I've used a lot of copper core autolite plugs and never had a problem with any of them. I bought several sets of 103's on closeout locally(for something like $1 for a pack of two) and I'm currently running them in both of my TGP's. I can tell absolutely no difference between them and the AC Delco R42LTS'.

For what it's worth, I recently talked to a rep at NGK and they told me that NGK, Denso, and possibly Honeywell(autolite) supply GM with spark plugs for the AC Delco brand.

[1988GTU]

THE BEST spark plug is one that sparks! Duhhhhhh!

[PCGUY112887]

can you give more detail as to why (copper core) autolites are junk?The 97-current W-body guys swear by them.
The stock plug is a 606 rite?Whats the delco part #,and whats the next range colder plug?

I believe it's the 97+ w-body L67 GTP guys that swear by the copper autolites. For them it may be that way because different plugs react differently to boost vs the N/A 3400.

[Superdave]

I haven't used the copper core, just the regular platinums. i put a set in my old GAGT and they started acting up after about a month. I replaced them with 50K used iridiums from my spare 3500 and put another 20K on the car with no problems.