Just wondering if anyone has used Iridium IX spark plugs in there Magna

Yes. They are a good plug.

Copper core: NGK BKR5ES11 = $1.49
Platinum: NGK BKR5EGP = $2.29
Iridium: NGK BKR5EIX11, BKR5EVXA11 Iridium IX = $5.90
(USA prices, Aussie prices much higher)

Copper good for 45,000 km, platinum good for 100,000, Iridium ???

Seeing I've been quoted about $13 for a platinum NGK locally, Iridiums would be more expensive again. There would have to be really good reasons to go for the Iridium plugs. Don't know/can't think of any.

Yes. They are a good plug.

"Good" in what way?
How much though?

A nice read!
http://www.ek9.org/forum/engine/4255-ngk-iridium-spark-plug-they-worth-extra-money-over-standard-plugs.html

Note the price: "Iridium NGK plugs (BKR7EIX-11PS) £40", I hope that's for a set of 4! lol

Ignore the advice to gap them, the platinum or iridium is just at the tip and if it gets weakened and breaks off in use, can potentially do all sorts of damage to the piston and bore. NGK plugs come pregapped anyway, hence the "11" at the end of some model numbers, denotes the correct 1.1 mm gap.

They're good quality plugs. I trust anything ngk and have heard reports of very little wear on the plug after 50,000+ km. Cost v benefits aside, they do their job well.

Set of 6 Iridium delivered to Sydney from UK via ebay about $48 including postage. I doubt if there is any noticeable difference in the car no matter what the plug but the advantage is that you don't have to touch them for 100,000km at which time you replace the timing belt and the hardened rocker cover gaskets.

Set of 6 Iridium delivered to Sydney from UK via ebay about $48 including postage. I doubt if there is any noticeable difference in the car no matter what the plug but the advantage is that you don't have to touch them for 100,000km at which time you replace the timing belt and the hardened rocker cover gaskets.

So pretty much the same as the cheaper platinum plugs then? lol

Note: ok, run the plugs for 100,000 km, but the belt needs to be changed after 5 years. Not likely that these two events will coincide, unless you do exactly 20,000 km a year.

ngk iridium plugs resist fouling, provide a more stable spark, and on a healthy engine will outlast platinum plugs (circa 150000km). manufacturers are now specifying them due to engines being required to run hotter and leaner, thus requiring a plug that can withstand a harsher environment, ignite leaner mixtures, and in most cases last a long time because they are buried "somewhere" in the engine.

Nothing wrong with Iridiums, or platinum plugs or the copper plugs for that matter.

The Mitsu 3.5L engine seems to be quite easy on plugs, front bank ones are supposed to be changed over at 45,000 km but will look fairly fresh at that distance and could be cleaned and regapped and go back in for a similar distance. You could run copper plugs on both banks for 60,000 km without running into misfire problems through the gap growing bigger.
Going to Iridiums is overkill, in my opinion, ie not cost effective.

Just don't expect any power increase.
Still, your choice.

They're over $20 a plug in NZ :(

I currently have a set of Irifium IX in my NL Pajero and a TF Magna - both running on gas. Because the recommendations for LPG are to use one grade colder plugs, I tried but couldn't get a grade colder than those recommended for petrol in Australia. I bought them from the US, but by the time postage was added, they were probably not that much cheaper than if I bought them here.

I installed them in the Pajero first and noticed a big improvement in low end torque. I then installed them in my wife's Magna and didn't say anything to her. She asked me "What have you done to the car?" "Why?" "Because it is going much better". I haven't really noticed much difference in fuel consumption.

Regarding life of the plugs, the Pajero had NGK Platinums in as original. I replaced them at 105000 km and the gaps had opened out to about 1.6 mm (the centre electrode had eroded away). This electrode is 0.6 mm diameter. The Iridium plug electrodes are 0.4 mm dia and that is really thin. The reason is because spark jumps from a sharp edge (or point) better and the thinner the electrode, the better the spark - hence the improvement in performance. I am concerned about the life of the plugs because there is less electrode to wear away. I had reason to pull the Magna plugs after about 10000 km, and there didn't seem to be much difference in the gaps, so maybe they are going to be OK. I don't dare try to check the Pajero because it is not a nice job (putting it nicely) to get at them.

Another recommendation by the plug manufacturers for LPG operation is to close the gap by 0.1 mm. In view of the 1.6 mm gap in the orgiinal Pajero plugs, I set the gaps to 0.9 mm (recommended range 1.0 - 1.1 mm). Hopefully when they have done 60000 km, they will still be within reasonable gap.

Were the original plugs shagged? I cant see how changing plugs would offer massive performance improvements other than the old plugs offering a poor spark for proper detonation

One thing about spark plugs - if you have an oil burning engine, they will begin to misfire from fouling long before the spark becomes unreliable from erosion and widening of the plug gap. Having Platinums or Iridiums in the engine won't help with that.

Still, what you run is entirely up to you. I have 2 sets of 6 platinum NGKs ready to go in my TJ and TL, but the current plugs of indeterminate age and km - whatever they are, probably platinums in the rear and copper in the front - are doing fine, so no hurry. Waiting for misfires or loss of power or increased fuel consumption before I touch them. When I pull them out I will be posting pictures, but it might take a year or 2. lol

Should the plugs be 1.0mm or 1.1mm on a 3.5L KF?

Should the plugs be 1.0mm or 1.1mm on a 3.5L KF?

1.1 mm, but 1.0 is ok. If you get NGKs that end with "-11" they are factory gapped at 1.1 mm and go straight in.
I buy the pregapped platinums because I don't trust the weld between the fine platinum tip and the rest of the core, if it gets damaged in the gapping process it may break off in use, leading to a misfire and possible piston/bore damage.

Used to be common practice to under gap new copper plugs slightly so that by the time they did 5,000 to 10,000 km the gaps would still be right.

1.1 mm, but 1.0 is ok. If you get NGKs that end with "-11" they are factory gapped at 1.1 mm and go straight in.
I buy the pregapped platinums because I don't trust the weld between the fine platinum tip and the rest of the core, if it gets damaged in the gapping process it may break off in use, leading to a misfire and possible piston/bore damage.

Used to be common practice to under gap new copper plugs slightly so that by the time they did 5,000 to 10,000 km the gaps would still be right.
The NGKs I have were set to 1.0mm (checked manually)... The range under the bonnet said 1.0-1.1mm so yeah. Figured should be fine.

Dave wrote: "Were the original plugs shagged? I cant see how changing plugs would offer massive performance improvements other than the old plugs offering a poor spark for proper detonation ".

The original plugs were doing fine when I pulled them. The gap startled me - you could just about walk through it! In removing the plugs, I disturbed the HT leads and then progressively things fell apart until I bit the bullet and replaced everything. As stated, the sharper the point on the centre electrode, the better the spark. Perfomance is better, but overall fuel consumption not much difference - prevailing winds would account for any measured differences

One thing about spark plugs - if you have an oil burning engine, they will begin to misfire from fouling long before the spark becomes unreliable from erosion and widening of the plug gap. Having Platinums or Iridiums in the engine won't help with that.


Actually NGK have addressed this very problem on their iridium ix plugs

this is from their site:

CARBON BURN-OFF

NGK's new Iridium IX spark plugs overcome fouling problems with a patented two stepped centre electrode.

This new design makes room for a very small air gap between the centre electrode and insulator nose. During operation, in conjunction with the main spark a secondary micro discharge is generated in this air gap.

< A secondary micro discharge effectively burns off the carbon deposits as they form – this is often refered to as active burning of the carbon

Since the carbon deposits do not reach the centre electrode, the plug continues to spark correctly at the gap, eliminating misfires and rough idle/running problems.

http://www.ngk.com.au/images/iridium-ix/active-burning-carbon.gif

Actual field results:

The effectiveness of the two-stepped centre electrode to burn off carbon deposits can be seen by the white ring surrounding the centre electrode. >

http://www.ngk.com.au/images/iridium-ix/field-results.gif

Smart thinking, that is!
Anyone prepared to put in Iridium plugs and report back after 150,000 km to tell us how they went? lol

They're over $20 a plug in NZ :(

order from rockauto

6 of them (http://www.rockauto.com/catalog/moreinfo.php?pk=69404) will cost less but then youll need to add shippin

http://www.rockauto.com/getimage/getimage.php?imageurl=http%3A%2F%2Fwww.rockauto.co m%2Finfo%2FNGK%2FNGK7086-1.jpg&imagekey=69404-0&width=450

"Anyone prepared to put in Iridium plugs and report back after 150,000 km to tell us how they went? "

Well, I have about 25000 km on a set in my Pajero (and about 20000 km in the Magna), but I am slowing down, so it will be a while before any definitive results come through. So far, so good. I don't intend to make them last 150000 km though - 100000 will be enough for me.

lol Just me being cheeky there.
I've never done more than 100,000 km in a car I've owned before it got traded/sold/wrecked, so for me the Iridiums would be overkill.
If you run a Taxi for 1,000 km a week, that would be a different story though.

thanks Max as i would have probably paid $60 for the 3 x rear plugs

instead i got 6 x plugs and a rocker cover gasket/plug kit for $67.42 delivered

thanks Max as i would have probably paid $60 for the 3 x rear plugs

instead i got 6 x plugs and a rocker cover gasket/plug kit for $67.42 delivered

Does that make you a rockauto.com convert? lol
Check out their prices on other things too, like cam belts, cam belt kits, ancillary drive belts and air cleaners to name a couple.
I honestly don't know why local prices are so high that you can import some parts from the USA at half the cost despite the high shipping charges.

yeah i did check out other stuff but the shipping calculator went spastic on me when i added a single belt

we always pay more in OZ for every thing

they say were used to paying more which is BS

my other toy is a harley so i know about being gouged on prices

yeah i did check out other stuff but the shipping calculator went spastic on me when i added a single belt


Probably the item you added would have come from a different location and you would be up for a second shipping charge and would have received 2 separate packages. Something to watch out for when you shop at rockauto.com

That link is not for the Iridium IX's, it's for the lower spec'd G-Power.

Smart thinking, that is!
Anyone prepared to put in Iridium plugs and report back after 150,000 km to tell us how they went? lol

well i installed 6 of them at 73000km and ive just hit 160,000, i just recently pulled one to check it, and its as sharp as it was when i installed it.
i should hit 223,000km in 4 years, should be a real eye opener because my beast has been on lpg since 83,000km.

Impressive!

Note: ok, run the plugs for 100,000 km, but the belt needs to be changed after 5 years. Not likely that these two events will coincide, unless you do exactly 20,000 km a year.
This is a really good point. The belt has to be changed at 5 years or 100K at which point the plugs are easily accessed.
I dont see why i'd buy iridium when the platinum easily last for that 100K, probably quite a bit more?
Unless you believe the iridium can last 200K.