[brad65ford]

Just wanted to share these photos and thoughts for what I'd suggestion suggest the need to change you plugs on these cars more often. Since we were doing CTS catted Dp's figured what better time than now to do some colder plugs. Wow for 18k miles, running stock everything (only ran stage 1 for 250 miles) they look like crap imho. If you guys haven't changed your stock plugs, even if your stock and or have more miles than mile.. do it asap!!! These cars make a lot of power even stock and put a lot demand on the stock plugs.

[AngryInch]

Did you check the gap on the used plugs? I’m switching mine out. I ran that boostane crap… going 2 step colder.

[brad65ford]

just checked, they are .026 across the board. Not sure what they were when they were know though. The new ngk's we set to .021 She runs a little rough at idle some times worse than other times, it did this prior doing DP and plugs but its a little rougher not sure if 2 step colder plugs make that much of a difference and or the smaller gap. Feels now pulls great, do believe the new plugs.

[eric97hoh]

every 10-15k miles we should change plugs i belive i agree

[brad65ford]

Originally Posted by eric97hoh

every 10-15k miles we should change plugs i belive i agree

For stock I'd agree, though mine at 17/18k look like poop imho. Doubt they'd look much better 3k miles ago. Though again I don't know what was done prior but I'm going by the condition and the stock tuning, I believe it was driven (normal). Personally id say sooner, more like 4-5k miles especially if anyone drives like me and is tuned. Its pretty common to change plugs more often when making more power, these f'er make some serious jam/heat that is a lot of abuse on plugs. Wondering.. someone said the stock bmw plugs are crap, not sure if this is why mine we so bad.

[eric97hoh]

Originally Posted by brad65ford

For stock I'd agree, though mine at 17/18k look like poop imho. Doubt they'd look much better 3k miles ago. Though again I don't know what was done prior but I'm going by the condition and the stock tuning, I believe it was driven (normal). Personally id say sooner, more like 4-5k miles especially if anyone drives like me and is tuned. Its pretty common to change plugs more often when making more power, these f'er make some serious jam/heat that is a lot of abuse on plugs. Wondering.. someone said the stock bmw plugs are crap, not sure if this is why mine we so bad.

not gonna lie it looks like your plugs went through a hurricane and tornado if mine are like that I'm changing them before going e30 stage 1 I'm on 7000 miles

[DB_BMW]

Here are my plugs at 18500 miles. Just replaced them with NGKs 1 step colder gapped at .022. The stock ones weren't gapped the same, some where more than other plugs.

[brad65ford]

hard to see the tips in your photo though they looks similar to mine but better condition.

[spuntyb]

My car just informed me at 16500 miles that I'll need spark plugs at 18k. Funny thing is, I could already feel the difference around 16300. It's subtle, but when you drive it every day, and do enough miles, you feel these things. My throttle is a tiny bit squishier than normal, the sound isn't quite the same, and I started to get the little shudder when I start the car from time to time that normally isn't there. Who knows, I may also need coil packs or something else. No check engine lights or warnings, and no loss of actual power, but I agree that 18k when you daily this car may be too long. 15k is probably the sweet spot for a stock motor.

Thanks for sharing!

[AHall]

Originally Posted by spuntyb

My car just informed me at 16500 miles that I'll need spark plugs at 18k. Funny thing is, I could already feel the difference around 16300. It's subtle, but when you drive it every day, and do enough miles, you feel these things. My throttle is a tiny bit squishier than normal, the sound isn't quite the same, and I started to get the little shudder when I start the car from time to time that normally isn't there. Who knows, I may also need coil packs or something else. No check engine lights or warnings, and no loss of actual power, but I agree that 18k when you daily this car may be too long. 15k is probably the sweet spot for a stock motor.

Thanks for sharing!

Originally Posted by spuntyb

My car just informed me at 16500 miles that I'll need spark plugs at 18k. Funny thing is, I could already feel the difference around 16300. It's subtle, but when you drive it every day, and do enough miles, you feel these things. My throttle is a tiny bit squishier than normal, the sound isn't quite the same, and I started to get the little shudder when I start the car from time to time that normally isn't there. Who knows, I may also need coil packs or something else. No check engine lights or warnings, and no loss of actual power, but I agree that 18k when you daily this car may be too long. 15k is probably the sweet spot for a stock motor.

Thanks for sharing!

At what mileage does BMW recommend the spark plugs be changed? 15000 miles seems really low.

[spuntyb]

Originally Posted by AHall

At what mileage does BMW recommend the spark plugs be changed? 15000 miles seems really low.

At 16500 miles the car and my app told me the car would need oil service, new spark plugs and an air filter in 1500 miles, so 18k.

[JK-M5]

i'm currently on a service plan and the plugs get changed at 24,000 miles

[16HC]

I had my plugs changed out at 30k miles. I had the dealer do it = $900. High price but I am not familiar w the F90 engine. They look good to me. What do you all think? Sorry for pic quality…best I could do on my iPhone 7.

[HUM5INT]

Originally Posted by brad65ford

Just wanted to share these photos and thoughts for what I'd suggestion suggest the need to change you plugs on these cars more often. Since we were doing CTS catted Dp's figured what better time than now to do some colder plugs. Wow for 18k miles, running stock everything (only ran stage 1 for 250 miles) they look like crap imho. If you guys haven't changed your stock plugs, even if your stock and or have more miles than mile.. do it asap!!! These cars make a lot of power even stock and put a lot demand on the stock plugs.

Ironically every BMW I've had and serviced….the mechanics have always said the same thing - Bosch plugs are utter garbage. I just got my M5C a couple months ago but I'm assuming I'll be changing them somewhere between 12-14k from what these past mechanics told me.

[pbonsalb]

I had my plugs changed out at 30k miles. I had the dealer do it = $900. High price but I am not familiar w the F90 engine. They look good to me. What do you all think? Sorry for pic quality…best I could do on my iPhone 7.

What are the gaps? They look big but it is hard to judge an extra few thousandths from a photo and even harder from a bad photo.

[AHall]

Originally Posted by 16HC

I had my plugs changed out at 30k miles. I had the dealer do it = $900. High price but I am not familiar w the F90 engine. They look good to me. What do you all think? Sorry for pic quality…best I could do on my iPhone 7.

Your plugs do not look bad at all. If you do not mind me asking, do you have any kind of engine tune/modification?

[MVPMotoring]

Originally Posted by DB_BMW

Here are my plugs at 18500 miles. Just replaced them with NGKs 1 step colder gapped at .022. The stock ones weren't gapped the same, some where more than other plugs.

When you see ORANGE in the white area, that is OLD/worn and time to go ASAP!

[pbonsalb]

Or it means you used a fuel additive with mmt?

[Pugnacious]

Originally Posted by azpaul

Ironically every BMW I've had and serviced….the mechanics have always said the same thing - Bosch plugs are utter garbage. I just got my M5C a couple months ago but I'm assuming I'll be changing them somewhere between 12-14k from what these past mechanics told me.

I was the parts manager at a Southern California authorized BMW car dealership in the early to late 70’s. At that time all US model BMW’s (1602/2002, 2500/2800/Bavaria and 2800CS/3.0CS) used the same Bosch spark plug, a W200T30.

If you drove the BMW like you drove a Buick, you would foul the plugs. The W200T30 was just too cold for the US market but try telling that to the all-knowing BMW AG and Hoffman Motors (Max Hoffman was BMW’s US distributor before BMW NA took over in the mid 70’s). Much to Hoffman Motors chagrin I was able to source a hotter Bosch spark plug, the W175T30 from an outside vendor in Arizona for a third of the price. Fouling problem solved. BMW eventually went to the hotter plug.

Then a vendor that I bought shop supplies, fasteners, Coco floor mats etc. from offered NGK spark plugs. Putting a Japanese spark plug in a German car put BMW AG and Hoffman Motors in a tailspin, but it was a far superior spark plug. I guess some things never change.

[HUM5INT]

Originally Posted by Pugnacious

I was the parts manager at a Southern California authorized BMW car dealership in the early to late 70's. At that time all US model BMW's (1602/2002, 2500/2800/Bavaria and 2800CS/3.0CS) used the same Bosch spark plug, a W200T30.

If you drove the BMW like you drove a Buick, you would foul the plugs. The W200T30 was just too cold for the US market but try telling that to the all-knowing BMW AG and Hoffman Motors (Max Hoffman was BMW's US distributor before BMW NA took over in the mid 70's). Much to Hoffman Motors chagrin I was able to source a hotter Bosch spark plug, the W175T30 from an outside vendor in Arizona for a third of the price. Fouling problem solved. BMW eventually went to the hotter plug.

Then a vendor that I bought shop supplies, fasteners, Coco floor mats etc. from offered NGK spark plugs. Putting a Japanese spark plug in a German car put BMW AG and Hoffman Motors in a tailspin, but it was a far superior spark plug. I guess some things never change.

Wow great detailed insight. Thank you!!

[16HC]

Originally Posted by pbonsalb

What are the gaps? They look big but it is hard to judge an extra few thousandths from a photo and even harder from a bad photo.

Sorry, I don’t know. They were OEM plugs changed out w OEM plugs, so whatever gap the stock plugs are.

[pbonsalb]

Actually, they may have opened up over 30k miles, which can cause misfires if boost is raised.