Spark Plug Questions

[OriginHacker21]

I did a quick search on the internet on spark plugs. Seems like Iridium - best performance, Platinum is long life, and copper are the plugs that everyone used to use.

I've got the 2.2L Ecotec in a 04 Pontiac Sunfire - been told I have the platinum plugs in there now - my car is at 70,000 miles and now seems like a good time to change them.

Few Questions: For someone who drives 220 miles (99% highway @ 70-75mph @ 2500-2900 rpm) every weekday and does some city driving on the weekends - what is best? Plat, Irid, or Copper?

Goal to get engine to 400,000 miles so: How often to change? History of maintenance: Chevron/Shell gas - Chevron w/ Techron every 5k miles. Still averaging 37MPG highway.

Thanks for all the info/comments/suggestions. -Paul

 

[kcryan]

My knowledge of Iridiums say stay away, i know that if they get slightly coated in fuel, they have a tendancy to mis fire like crazy. So unless your dragging this thing...steer clear would be my reccomendation.

Id say go with a good set of platinums, i personally favor NGK's. Copper should be fine too, but you'll have to change them more often.

Getting to 400,000 should be doable, i doubt plugs will have much of an effect, so long as you keep them semi fresh.

 

[wavinwayne]

FWIW, I've been running cheap Autolite copper plugs in my '00 VW 1.8T engine for over 20k miles with no problems whatsoever. VW says that only NGK platinum plugs are appropriate for this application. My VW runs just as good with the $2 Autolites as it did with the $10 OEM NGK's. If it makes any difference, I drive the VW 80+ highway miles round-trip 5-6 days a week.

My conclusion = If you do mostly highway driving & don't mind changing plugs every year or so, go with cheap copper plugs. If you do a lot of stop & go and/or don't want to change the plugs for a long time, go with platinum or iridium plugs, or whatever the manufacturer recommends for your engine.

 

[kapps]

I agree. Iridiums usually are meant for high performance engines. I'll be switching over to them in my MINI Cooper S. Interestingly, our Honda Insight comes stock with Iridium plugs and 105k mile change intervals. They're needed due to the fact that the engine can run over 20:1 A/F ratio and Iridium requires less voltage to spark (plug gap is >1mm). For your driving style, Platinums should be fine.

 

[SteveU]

I would go with iridium, they run good in everything I have put them in. Best way to get the most mileage & most miles possible out of an engine is to have it running at top form all the time. To me that is having plugs & other parts that don't need changed all the time to give top efficiency. Back when I was in the USMC I would adjust the points every week to keep the dwell spot on all the time & changed plugs every 3000, oil every 1500 or so miles. With the job I have now & a family I just don't have the time or inclination to spend that kind of time maintaining a car. Iridiums are supposed to be very resistant to fouling & take less voltage to fire. With the mileage you're putting on, copper would start going south fairly quick, with iridiums once a yr plug changes should be plenty.

 

[Trav]

GM installs iridium plugs on the Denali 6.0 as OEM.i see them with over 100k everyday,these are not high performance vehicles just daily drivers.FWIW i put NGK iridiums in my 5.4 expedition which are a real pita to change and even after seafoam they didn't misfire.

 

[OriginHacker21]

Well - thanks for all the information. I read every post before heading off to the auto-store (AutoZone) - I know the owner so he is very helpful - but the rest of the employees don't know squat.

He looked my car/engine up on the computer and said they don't make iridium plugs for my engine yet. Also, he didn't carry the copper for my car. He had +2 and +4 Bosch Platinums ($4.99 vs $6.99). So, went with the +4 Bosch plats and we'll see how they do. I'll be installing them for the first time tonight - he suggested some "boot protector and anti-seize" for the threads.

I'll see if I can't get a picture of my old plugs vs the new up on photobucket here in a little bit.

Again, thanks for all your help! We'll see if the car runs after its surgery...

-Paul

 

[The Critic]

Bosch Platinum +4?

If your GM Ecotec 2.2 has a DIS, many people have had mixed results with Platinum +4 Plugs in DIS. Supposedly the four ground electrodes wear down rather quickly (no platinum pads on the ground electrodes) or impede the correct operation of the system causing misfires. Not everyone though, so let us know how it works out for you.

The "OE style" plugs for your Ecotec 2.2 (2004MY) are the double platinum type.

Autolite Double Platinum APP5263- $3.99/plug
NGK Laser Platinum PTR5A-13- $7.99/plug

Prices are from Kragen. They may or may not have these in-stock, but they can order them for you at no additional cost.

Hopefully the Platinum +4 Plugs will work out for you, but if they don't, those are some alternative plugs you can try.

Good Luck!

 

[punisher]

What is so difficult about looking at the owner's manual/underhood decal and getting a stock replacement plug? I know it goes against the grain of this forum but sometimes stock replacements actually are the best all around option.

 

[OriginHacker21]

The spark plug transfer was a ... success!!!

It was a little difficult to get all the right sizes but everything was undone - the old plugs were a PIA to take out (really tight in there) - but they looked good (I don't know what bad plugs look like anyway).

I took the anti-seize and coated the threads like the guy told me and put in the new spark plugs after a Miller Lite. I took some of that boot protectant and did what it asked as well. So everything screwed into place nicely - the only weird thing were the rubber boots that connected the metal tops (sorry not a mechanic here) to the spark plugs. They didn't fit very well so you kind of just had to push them onto the spark plug then let down the top part onto them and screw the top part onto the engine.

Well, I was shaking and held my breath - started the car and it turned and started with the first turn. The engine sounds as smooth (if not smoother (just in my head probably) than before). I ran it for about 30 seconds and turned it off. Everything looks good.

BTW. My dad was looking over the entire procedure and helped out a lot (his father is a lifelong mechanic. My dad has helped rebuild engines before) - to make sure everything went according to spec.

Pictures of old spark plugs will be here soon!

 

[OriginHacker21]

SparkPlugs

SparkPlug1

SparkPlug2

TheCritic - thanks for the spark plug types - If these misfire and cause problems - I will use the two references that you gave me. I am a little worried about this

. Could this cause damage to the engine? Also, I have no idea what a DIS is.. OK - so they will wear down quickly - how long would you recommend running these? 20k? 30k? 60k?

punisher - The manual recommends the ACDELCO plugs - and I don't have a local shop that has those - I could go to the dealer and get them but I assumed that like different brands of oil - the other spark plugs should work. Looks like I could be wrong here. I am going to look into it more.


Now I'm really worried.

 

[The Critic]

No, I doubt that you'll cause damage to the engine.

DIS= Distributor-less Ignition System. In short, it fires twice as often as a conventional ignition system (correct me if I'm incorrect) and thus requires better plugs (or more frequent changes). Commonly, DIS use double platinum plugs (platinum pads on ground and center electrodes) to maximize the longevity of the plugs.

I'd just run them until you start getting poor fuel economy and/or misfires or 100k, whichever comes first.

If the car runs fine with them, then consider yourself lucky. Who cares.

If it doesn't run correctly, then you know where to go.

Engine just uses double platinum plugs...that's the type...if ever need to buy plugs again...look for that.

 

[OriginHacker21]

Thanks for the info - I start work next Wednesday (220 mile/day drive) so I'll report back here on how they run. I also will do some driving tomorrow.

I will definitely get the double platinum plugs next time. Will keep an eye on fuel economy, misfires, and will change them before 100k just like this time.

Whooo hooo another DIY job done

Now to change out coolant, power steering, and brake fluids...

 

[OriginHacker21]

Interesting article on the spark plug configuration thing in the Ecotec engine - also discusses the DIS.
GMArticle

 

[Brogy]

Those old plugs looked great, just what you'd expect from any with 70k miles on them.

Honestly about the type, it doesn't really matter. Iridium or platinum, it doesn't matter. I wouldn't even hesitate to get copper. It only sparks, thats it. Only real difference is how long you plan on leaving them in for. I'd go with platinum for the price, iridium costs twice as much as platinum for maybe 30k miles more service.

 

[stroked93]

I have been in the parts bussiness for 12 years. and on ocasion had a bosch platinum plug returned for a misfire. I have never had one returned for a misfire on anything other than the vortec 5.0 or 5.7 engine and I have sold a bunch of these plugs. Last Year I had the opportunity to speak with an engineer from Bosch Spark plugs face to face. asked the question and was presented a wealth of info on paper regarding instances of misfires in gm vehicles. in all cases investigated and there were many the cause of the misfire was located in the wires, cap and rotor or a weak coil. yes he worked for bosch but I believed him, for one simple reason I had only had returns on 3-5% of the product sold for those applications and not all of them.

 

[The Critic]

On Platinum or Platinum+4? Bosch Platinums seem to be fine...its their Platinum +4s that seem to give people issues.

 

[stroked93]

on either . if the four ground electrodes wear too quickly because there is no platinum pad then wouldn't the standard platinum with one ground electrode wear 4 times faster? not that your info is wrong there is a issue with these plugs in vehicles that run properly on oe plugs. but have other ignition system components on the edge of their life cycle. just my 2 cents

 

[The Critic]

Honestly...I can't remember for sure...but I recall reading something posted by someone who had issues with the +4 plugs and he commented on how there was an issue with wear and the ground electrode setup.

Nevertheless, single plat. plugs with no plat. pad on the ground electrode may work fine in DIS, but need to be replaced every 30k or so due to wear on the ground electrode. I do not recall seeing any MFG recommend using single plat plugs in DIS...but Bosch does recommend using their Platinum +4 in DIS apps...that's the difference.

 

[stroked93]

there is no doubt in my mind that the OE double platinum are better. and will last longer I just am no longer willing to blame the misfire on the plugs that is all. nice chatin with ya.