[lowrydr310]

I installed new plugs and coils on my old 06 325i in 2018. My niece has the car now and it has 260K miles on it. I just removed the spark plugs to inspect while looking at an injector issue and noticed that the ground electrodes are severely worn, and the gap has almost doubled to 0.080!

Coils are OEM Bosch, plugs are NGK LFR6AIX-11. I thought iridium plugs are supposed to have a significantly longer life. I've used NGK iridium plugs in my Hondas since new and even at 100K miles on two different cars (per Honda's service recommendation) the plugs have negligible wear.

Why are they wearing so quickly in the N52?

I regapped them to 0.043 but plan to replace them in a few months due to the excessive wear.

[jbellk75rt]

Just a WAG but maybe coils are too hot? How many miles on the plugs?

ps, �� on your location.

[The Nightman]

NGK Iridium IX LFR6AIX-11 have nickel grounds so they are only rated for 50k miles. If you are looking for longer life, Bosch Double Platinum FR7NPP332 and NGK Laser Platinum PLZFR6A-11S have platinum centers and grounds, and are rated for 90k miles.

IIRC early model year N52s with the different ignition coils use JIS height plugs so you might want to verify fitment. The OE plug would be NGK Laser Iridium ILZFR6D11 with an iridium center and platinum ground, and is rated for 100k miles.

[lowrydr310]

Originally Posted by The Nightman

NGK Iridium IX LFR6AIX-11 have nickel grounds so they are only rated for 50k miles. If you are looking for longer life, Bosch Double Platinum FR7NPP332 and NGK Laser Platinum PLZFR6A-11S have platinum centers and grounds, and are rated for 90k miles.

IIRC early model year N52s with the different ignition coils use JIS height plugs so you might want to verify fitment. The OE plug would be NGK Laser Iridium ILZFR6D11 with an iridium center and platinum ground, and is rated for 100k miles.

Interesting. There are around 45K miles on these plugs and coils, so if their service life is in fact 50K that completely makes sense.

When I first got the car it had a misfire due to a bad coil so the first thing I did was replace all spark plugs and coils. At the time I was new to the platform and I wasn't aware of the nuances of the different coils and plugs specified for these cars. It has the current Bosch coils and LFR6AIX-11 spark plugs. The car is a 6/06 build.

I currently have a 12/05 build 330i and know that these coils from the 325 won't fit as is. The connectors for the coils on my 330i are keyed differently. Apparently 4/06 was the changeover date. Were these older coils designed for the JIS height spark plugs?

[crashoverride]

Coils changed plugs remain the same.
It was so weird I too have a 4/06 build and it has the old wiring harness. So weird to change fitment and harness within first few months of initial introduction of a new body style

[Mike K]

Originally Posted by The Nightman

NGK Iridium IX LFR6AIX-11 have nickel grounds so they are only rated for 50k miles. If you are looking for longer life, Bosch Double Platinum FR7NPP332 and NGK Laser Platinum PLZFR6A-11S have platinum centers and grounds, and are rated for 90k miles.

IIRC early model year N52s with the different ignition coils use JIS height plugs so you might want to verify fitment. The OE plug would be NGK Laser Iridium ILZFR6D11 with an iridium center and platinum ground, and is rated for 100k miles.

So nickel grounds equal 50k life yeah? What about copper grounds then?

Like these:

NGK LZFR6AP-11GS

[The Nightman]

Originally Posted by Mike K

So nickel grounds equal 50k life yeah? What about copper grounds then?

Like these:

NGK LZFR6AP-11GS

The core and ground material is always copper as far as I know. It's the coating that determines life span (nickel vs platinum vs iridium).

NGK LZFR6AP-11GS has a platinum tip and nickel ground, and is rated for 50k miles. BMW specs this plug for the N52T in the F10 and F25 based on a bulletin from December 2010: https://f01.justanswer.com/KJMmrtech...ATA_Repair.pdf

RealOEM shows that LZFR6AP-11GS (12120037663) can also be used on all N52s as of December 2009, but the above bulletin still specs the Bosch FR7NPP332 for ISO height plugs and NGK ILZFR6D11 for JIS height plugs (early model N52s).

Unaware of the shorter lifespan, I switched to NGK LZFR6AP-11GS thinking that the latest was the greatest. I'll be going back to Bosch FR7NPP332 at my next change. Ironically, the double platinum plugs with the longer service life are cheaper...

[e91Owner]

Originally Posted by The Nightman

The core and ground material is always copper as far as I know. It's the coating that determines life span (nickel vs platinum vs iridium).

NGK LZFR6AP-11GS has a platinum tip and nickel ground, and is rated for 50k miles. BMW specs this plug for the N52T in the F10 and F25 based on a bulletin from December 2010: https://f01.justanswer.com/KJMmrtech...ATA_Repair.pdf

RealOEM shows that (12120037663) can also be used on all N52s as of December 2009, but the above bulletin still specs the Bosch FR7NPP332 for ISO height plugs and NGK ILZFR6D11 for JIS height plugs (early model N52s).

Unaware of the shorter lifespan, I switched to NGK LZFR6AP-11GS thinking that the latest was the greatest. I'll be going back to Bosch FR7NPP332 at my next change. Ironically, the double platinum plugs with the longer service life are cheaper...

That’s interesting… have always used ILZFR6D11 my 2010 e60/N52 and LZFR6AP-11GS on my 2011 e91/N52 because that’s what realoem called for. Both use the same Delphi coils, so it must not be a JIS/ISO spec issue. Given what you’ve said, though, I may start running ILZFR6D11 on my e91. May be a while, though, I changed them last in ‘21 and only put on 4K miles since

[Dirtleg]

Originally Posted by crashoverride

Coils changed plugs remain the same.
It was so weird I too have a 4/06 build and it has the old wiring harness. So weird to change fitment and harness within first few months of initial introduction of a new body style

I also have a 4/06 car and it has the newer style coil plugs on the harness. I did much investigating before purchasing new coils as the crossover date description wasn't clear to me.

Guess if you have a 4/06 car it could be either style.

[mrpriceisright]

Originally Posted by lowrydr310

I installed new plugs and coils on my old 06 325i in 2018. My niece has the car now and it has 260K miles on it. I just removed the spark plugs to inspect while looking at an injector issue and noticed that the ground electrodes are severely worn, and the gap has almost doubled to 0.080!

Coils are OEM Bosch, plugs are NGK LFR6AIX-11. I thought iridium plugs are supposed to have a significantly longer life. I've used NGK iridium plugs in my Hondas since new and even at 100K miles on two different cars (per Honda's service recommendation) the plugs have negligible wear.

Why are they wearing so quickly in the N52?

I regapped them to 0.043 but plan to replace them in a few months due to the excessive wear.

The simple answer is: what coils do you have? BMW changed the original coils to HP (high power) coils sometime after 07 and the HP coils require different plugs (ISO height 50.5mm instead of JIS 53mm). For whatever reason, they specify dbl platinum with the new coils instead of iridium.

I have been battling this problem on an N52 (07) for quite some time (over a year) and it took quite some time to figure out the HP coil problem. I have been seeing burned down center electrode with widening gap with all iridium plugs I've tried. I have now replaced all coils with the HP iso model (Delphi GN10571) but I have yet to find an Iridium plug (even ISO) that lasts more than 10k miles. I start getting erratic running and misfire codes somewhere in the 5-10k mile range.

I've given up on iridium for now and just put in some of the recommended BOSCH FR7NPP332 (dbl plat) to see if they do any better. here is the HP coil/plug part #'s

coils HP ISO Delphi GN10571 Delphi 12138616153
Bosch Ignition Coil 0221504470, 12137594937

Plugs: per TIS high power ISO plugs spec’d (both dbl platinum):
iso PLZFR6A11S (up to 2009)
BOSCH FR7NPP332
ISO LZFR6AP11GS (since 2013)

If someone knows an ISO Iridium plug that lasts with the HP coils I would like to know about it.

[drawz]

So what are the proper plugs for a 3/06 build 330xi? I just ordered Bosch 0221504465 coils which fit the original (old style) harness plug and Bosch FR7NPP332 plugs. Is this going to work? Sounds like NGK ILZFR6D11 is JIS and the correct height for these coils based on posts here, but I want to double check before exchanging.

Note FCP sells these Bosch coils and plugs together in a kit for up to 4/06

[mrpriceisright]

Originally Posted by drawz

So what are the proper plugs for a 3/06 build 330xi? I just ordered Bosch 0221504465 coils which fit the original (old style) harness plug and Bosch FR7NPP332 plugs. Is this going to work? Sounds like NGK ILZFR6D11 is JIS and the correct height for these coils based on posts here, but I want to double check before exchanging.

Note FCP sells these Bosch coils and plugs together in a kit for up to 4/06

As FCP Euro sells this as KIT-12137594936KT with the FR7NPP332 plugs I would think they are the correct ISO plugs (contact FCP to confirm) and that the coil is the updated HP ISO. This appears to be a special model coil made because I believe the original harness has a rib on the coil connector. I think I saw somewhere you can remove the rib and use the standard new coil but I haven't confirmed that. I would also compare the height of these coils with the originals.

[drawz]

Originally Posted by mrpriceisright

As FCP Euro sells this as KIT-12137594936KT with the FR7NPP332 plugs I would think they are the correct ISO plugs (contact FCP to confirm) and that the coil is the updated HP ISO. This appears to be a special model coil made because I believe the original harness has a rib on the coil connector. I think I saw somewhere you can remove the rib and use the standard new coil but I haven't confirmed that. I would also compare the height of these coils with the originals.

Yes, this coil fits the old harness and are an updated part number. I replaced a single coil earlier due to misfire with one of these and it fit the original plugs seemingly just fine and now I'm ready to do the plugs and rest of the coils. Given the kit, I guess I'll just roll with it and there's always that lifetime warranty if needed

[SmiLer89]

Originally Posted by mrpriceisright

The simple answer is: what coils do you have? BMW changed the original coils to HP (high power) coils sometime after 07 and the HP coils require different plugs (ISO height 50.5mm instead of JIS 53mm). For whatever reason, they specify dbl platinum with the new coils instead of iridium.

I have been battling this problem on an N52 (07) for quite some time (over a year) and it took quite some time to figure out the HP coil problem. I have been seeing burned down center electrode with widening gap with all iridium plugs I've tried. I have now replaced all coils with the HP iso model (Delphi GN10571) but I have yet to find an Iridium plug (even ISO) that lasts more than 10k miles. I start getting erratic running and misfire codes somewhere in the 5-10k mile range.

I've given up on iridium for now and just put in some of the recommended BOSCH FR7NPP332 (dbl plat) to see if they do any better. here is the HP coil/plug part #'s

coils HP ISO Delphi GN10571 Delphi 12138616153
Bosch Ignition Coil 0221504470, 12137594937

Plugs: per TIS high power ISO plugs spec’d (both dbl platinum):
iso PLZFR6A11S (up to 2009)
BOSCH FR7NPP332
ISO LZFR6AP11GS (since 2013)

If someone knows an ISO Iridium plug that lasts with the HP coils I would like to know about it.

Hi everyone, I want to replace my spark plugs , after 20k miles they don't perform well
At the moment I have coils Bosch 0221504470 Ignition Coil and spark plugs NGK ILZFR6D11 (1208) - Laser Iridium is that the correct set up ?
My cars is bmw 330 I auto 2006 with n52b30 engine
Thank you very much .