Hi Guys

Apologies in advance if this topic has been flogged to death - but it's not a general question - rather a more specific one. Our TJ is an unknown in terms of what the previous owner used - so with info gained on here I intend to replace all six of the plugs with Iridiums soon.

Found a pretty good deal on Ebay here (http://www.ebay.com.au/itm/6-PCS-NGK-IRIDIUM-IX-Spark-Plug-Set-OEM-Upgrade-BKR5EIX11-PART-5464-NEW-/221048174220?pt=Motors_Car_Truck_Parts_Accessories&hash=item33777f768c) - but if you use the sites search tool it says that they are not compatible with the 2002 Diamante?

Am I making a mistake in year/model - or is their site just flat out wrong?

Steve

BKR6EIX-11 are the right ones

BKR6EIX-11 are the right ones

Thanks Wombat - great value also on Ebay - and matches their selection guide too.

Cheers

Not sure if you are using LPG, but if you are it is reccommended to use a grade of plug which is one grade colder. I looked for the correct grade for my Pajero, but it wasn't listed in Oz. I got them from the states (good price too). From memory, it was what you are looking at here. They performed brilliantly in both my Pajero and my wife's TF (also on gas). Cannot say how long they will last, but from what I saw, I would expect them to go for the full 100000 km without the gap opening up too much.

spark plugs: change at:
NGK BKR5E11 Copper 45,000 km, pregapped
NGK BKR5EGP Platinum 100,000 km, pregapped
NGK PFR5G-11 2X platinum 100,000 km, pregapped

The 3.5L V6 is really easy on plugs, I've pulled the original double platinum plugs out of the rear bank of an engine at 136,000 km, looked at them and put them straight back to go up to 200,000 km. Iridiums will outlast the rest of the car.

The platinum plugs have a centre electrode 0.6 mm dia. The Iridium plugs have a 0.4 mm dia electrode. The thinner the probe the better the spark - ideally a point is best, but that will erode away. I couldn't detect any erosion in any of my iridiums, but I only had about 40000 on the ones in the Pajero and about 25000 in the Magna. Certainly you get a better spark with the Iridiums. Magnas are fairly gentle on plugs and leads - Pajeros are hell because the HT leads are only 5 mm dia, not 7 mm as in the Magna.

So its fine to use the iridiums in the rear bank (will they last as long as platinums, i heard some iridiums only last 30k kays...)

the ngk iridiums (bkr5eix-11) i had in my engine were almost perfect when i replaced them after 110,000km on LPG... only reason they got replaced was because i was in there replacing the rocker cover gaskets and ht leads that were destroyed by the oil (causing my poor magna to misfire on 4 cylinders) and i get them at trade price so couldn't be buggered having to pull the engine down again before the rocker cover gaskets needed replacing again.

the ngk iridiums (bkr5eix-11) i had in my engine were almost perfect when i replaced them after 110,000km on LPG... only reason they got replaced was because i was in there replacing the rocker cover gaskets and ht leads that were destroyed by the oil (causing my poor magna to misfire on 4 cylinders) and i get them at trade price so couldn't be buggered having to pull the engine down again before the rocker cover gaskets needed replacing again.

Sounds good enough for me :-)

spark plugs: change at:
NGK BKR5E11 Copper 45,000 km, pregapped
NGK BKR5EGP Platinum 100,000 km, pregapped
NGK PFR5G-11 2X platinum 100,000 km, pregapped

The 3.5L V6 is really easy on plugs, I've pulled the original double platinum plugs out of the rear bank of an engine at 136,000 km, looked at them and put them straight back to go up to 200,000 km. Iridiums will outlast the rest of the car.

You put plugs that were 136k back in your car because they looked ok? You are a stinge and a fool.

ok so is it: bkr5eix-11 or bkr6eix-11? and which ones are best for lpg?
i have to change them in my tj, and also my 3.5 dohc nj pajero and cannot seem to find which out of these 2 types are the right ones.

i assume the 6's are colder then the 5's so better for lpg. any problems with running colder plugs?

My plugs are at 400,00kms and counting.
Hell, basically every component in my cars is either factory original or one major service old. The timing belt is factory original at half a million kays...

Would love to know from someone who has tried both -6 and -5 in their car, and which is best for normal petrol, as I'm going to get stuck into mine soon.
Also, has anyone used RPW thermo block gaskets on intake / throttle body, and are they worth the dough? (Thinking about this also as I'll be up for gaskets anyway.)

I used both 6 & 5 in my 380, and never noticed any real difference. 5 is for stock motors, 6 (one range colder) is for warmed over motors and/or LPG. My motor was mildly warmed over (intake and exhaust mods, ChipTorque Xede piggyback ECU tuned for 98 RON with leaned out AFRs and advanced timing), so I used the 6 most of the time. But in hindsight I probably didn't really need the 6 and the 5 was plenty good enough.
I also fitted an RPW thermo block intake plenum gasket, but took it off and replaced it with a stock gasket a couple of years later. It did SFA to reduce the temp of the intake plenum, so in my opinion it's a waste of time & money. The extra thickness also caused some hassles with fitting the driver's side rear mounting bolt of the intake plenum (the one on the back near the firewall which mounts the plenum to a bracket), it was a real PITA to get it lined up and fitted properly. Dunno about a Magna/6G74 motor though.

ok so is it: bkr5eix-11 or bkr6eix-11? and which ones are best for lpg?
i have to change them in my tj, and also my 3.5 dohc nj pajero and cannot seem to find which out of these 2 types are the right ones.

i assume the 6's are colder then the 5's so better for lpg. any problems with running colder plugs?

Try the sixes if you run lpg, pull a front plug after a few thousand km and see if they are staying clean. Too cold plugs can foul and then misfire easier, too hot plugs can lead to pre-ignition. Why not get three cheap copper sixes and put them in the front bank, and see how they go after 5,000 km before you take the plunge on the more expensive 5 or 6 iridiums? Can't see a problem running sixes if your engine is not burning oil.

I need to change them in the pajero first, and there is no front bank on them! both are hard to change, so i want to make sure i make the right decision.

When I was in this position, I couldn't get the colder range plugs in Oz, so I went to Rockauto.com and bought 12 plugs - 6 for my wife's TF Magna and 6 for the NL Pajero (both runningon gas). I had no problems running the colder plugs on petrol on the Pajero. You could run just about anything on the Pajero with petrol - it was on gas that they became a problem. As for the Magna, it was very gentle on plugs and leads and again, you could use just about anything and get away with it.

You have to remember that the Magna has 7 mm dia HT leads, the Pajero has 5 mm dia leads and that is really too thin. Combine that with the additional stress with gas and you can have problems unless you are very careful in running the leads with correct spacing between them. Also, do NOT allow the leads to touch each other or earth when they cross paths. If you get it right, the leads are perfectly OK, but one minor glitch and BANG! - massive backfire (on gas anyway).

Pulled the front bank plugs (TJ 3.5l 6g74) had 6's in it which where worn out, humungous gap! New ones are 5's as that's what i found listed everywhere, incuding NGK's oz site. 6's are listed for 3.0l TJ so maybe that's where people get confused. Still got to fit the new Platinums in the rear bank.
PeterN