Seems NGK IX Iridium Spark Plugs Caused CEM Codes Limp Mode Topic is solved

[cn90]

Maybe your NGK Ir was counterfeit? Or you did not check the gap before installation.

I have NGK Ir in:
- 1998 BMW 528i for 10 yr.
- 2006 BMW X5 for 5 yr.
- 2004 Volvo XC90 2.5T for 5 yr (not 3 yr ad mentioned above).

I only use NGK Ir now.

PS: can you post a few photos of your NGK?

[dono]

I would love to see what happens if you reinstalled the NGKs again But that is asking a bit for my curiosity.

Honestly Id be curious too - they are still in the door storage driver's side barely used. The initial results were so traumatic though I doubt Ill ever run that experiment (maybe one day before the tow truck delivers her to her final reward at the crusher). Those were some very nasty codes and God only knows what was going on with my computers.

Im a rational person and like many here its beyond me how the NGK's could cause such problems for me and work great for others. Software perhaps, electrical systems particular to my vehicle (maybe there is a none OEM electrical part installed before my time problems; (Im second owner) . Maybe my CEM is sickly and couldnt stand a minor variation in voltage. One thing is for sure those profound problems with the vehicle went away the minute I changed out the NGK's and have not returned in 1,000 miles of mostly city driving. I dont think Ill put her in Tilt mode again to see.

[dono]

Maybe your NGK Ir was counterfeit? Or you did not check the gap before installation.

I have NGJ Ir in:
- 1998 BMW 528i for 10 yr.
- 2006 BMW X5 for 5 yr.
- 2004 Volvo XC90 2.5T for 5 yr (not 3 yr ad mentioned above).

I only use NGK Ir now.

PS: can you post a few photos of your NGK?

NGK (6418) BKR6EIX Iridium IX Spark Plug bought them at AutoZone. Ill see about a picture. My understanding is you arent supposed to adjust the gap on iridium (or platinum) plugs due to the fragile tips so I never thought to check the gap on them. Ill double check that too. I do know there are 2 lengths of NGK's so I checked and double checked by VIN when I purchased the plugs.

[cn90]

Here is how to spot counterfeit NGK:

https://www.driven2automotive.com/blog/ ... gust-2017/

PS: Do a google search "NGK Iridium Counterfeit" and you will see quite a few articles written on this subject.

[abscate]

If they are boxed , rather than blister packed, it it possible they were “ return counterfeit” , especially from a local parts store.

Buy expensive plugs local

Buy cheap plugs

Install expensive plugs.

Rebox cheap plugs in expensive box and return for cash.

The evil men do....

[dono]

Here is how to spot counterfeit NGK:

https://www.driven2automotive.com/blog/ ... gust-2017/

PS: Do a google search "NGK Iridium Counterfeit" and you will see quite a few articles written on this subject.

Thanks for the link - mine appear to be authentic based on the article parameters...

[EngineeringBloke]

I had NGK iridiums for a while (2 years, 15,000 miles) and then switched back to Volvo plugs while I chase down my low MPG. The NGKs were gapped at about .030" from the package. For a turbo, the air pressure is higher and so there is more resistance to the spark and hence the gap must be smaller - .028". I did regap the NGKs ground pin. It was tough, but the main risk is if you close the gap too much, then you have to open the gap and MUST avoid bending/touching the very fragile and thin, center electrode.

I really don't think there was a problem my NGKs.