[tjct]

2007 328xi coupe has the original factory spark plugs.Currently hit the 100k mile mark.How many miles has anyone gone before the original plugs began to cause problems? ...I know the maintenance light spells out plugs at 100k....thinking going longer,any thoughts?

[Welcome to NBA Jam]

For stock turbo engines, it's 60k. For BMW PPK tuned engines it's 45k. For non-turbo engines I want to say it's like 100k or something.

[PhaseP]

Wasn't the change because early ones had came with NGK Iridium, later ones switched to Bosch platinum?

Iridium lasts longer than platinum.
My thinking is if you have platinum spark plugs use 60K interval, if you have iridium 100K.

[hassmaschine]

plugs cost what, $30? why would you go longer than 100k miles? hell, on older engines they might have lasted 20,000 miles.

[tlow98]

Originally Posted by hassmaschine

plugs cost what, $30? why would you go longer than 100k miles? hell, on older engines they might have lasted 20,000 miles.

This. Plus, at 100k just do your coolant and trans fluid. Call it good and move on.

I'd consider adding coils if you intend to have the car for another 100k. If you are thinking of trading it in the next couple years then likely not.

[ctuna]

Changed at plugs about 75k and it ran smoother.
it ran smoother for awhile.
Just lost a coil at 82k replaced it and the mpg's came up a little.
Changed all the coils after the first one went .
Plugs and Coils are pretty cheap if you buy them from one
of the online places. Bought mine from FCP Euro.
06 325 xi wagon with N52
Better to do them all at once and not have to go back in or have
a coil fail when on the road somewhere.

The old plugs did not look terrible at that mileage.

[nsjames]

I changed what looked like original plugs at 103K miles.
they weren't great, but were not causing issues.

I did all the coils too because I like wasting money.
but really just didn't feel like doing them piece meal later.
now at 170K miles without issue.
I kept the two already had been replaced coils as spares.

[gbalthrop]

Originally Posted by hassmaschine

plugs cost what, $30? why would you go longer than 100k miles? hell, on older engines they might have lasted 20,000 miles.

My experience with 3/2007 328xi N52KP:
I bought the car at 130,xxx miles. It ran perfectly, NO SES or Fault Codes. Drove it like I stole it for ~ 2 weeks. THEN when accelerating at WOT in 1st & 2nd, to ~ 6,000 RPM shift-point, SES came on, ran VERY rough at cruise or idle for ~ 60 seconds, then SES went out and normal performance returned.

AFTER that happened twice, and I had a single "Misfire" code (say P0301) on each occasion, I ordered a new set of plugs and a single Bosch Coil (just in case). Changing plugs to proper .040" gap Bosch Platinum fixed issue and NO SES or Misfire Code in last 4+ years since (I still drive it like I stole it).

Upon removing OLD Plugs, the following findings:
1) Plugs were Platinum FR7NPP332 Bosch plugs with "BMW" logo; presumed ORIGINAL; further evidence that original: VERY difficult to get coil boots off plugs;
2) After several MILLION explosions, the plug gap had increased from original .040" gap (N52 engine) to .055" - .060" gap;
3) The plugs were otherwise in good shape, as were the coil boots; no oil, no carbon;

My interpretation of that data:
a) over 10 years and 130,000 miles, the plug gaps had enlarged as indicated, due to electrode erosion and/or cumulative explosive force on negative pin.
b) NO "Misfire" at sedate operation, but eventually when coil had to provide spark 50 times per second at 6,000 RPM, it couldn't "Reload" & produce enough voltage FAST enough to have spark jump the enlarged gap.
c) I probably COULD have just "Re-Gapped" the original Platinum Plugs to .040" and driven ANOTHER 130,000 miles, but I'm NOT THAT CHEAP (but CLOSE).

Current plug price for Bosch Platinum FR7NPP332, $7 at Autohaus:
https://www.autohausaz.com/pn/FR7NPP332

As for plugs on "older engines" needing to be changed in 20,000 miles, I'll show my "Dinosaur" credentials:
In 1967, I had a 427 Corvette. It had an EARLY Electronic Ignition. It had a 10.5 or 11:1 Compression Ratio (don't remember which), and burned Premium LEADED fuel. Any time I wanted to Auto-cross it I would have to change the plugs. They fouled in ~ 200 miles.

The good news is that in the 60's, many gas stations had "Sparkplug cleaning machines" that would decarbonize plugs by sand-blasting, and in my small town, I could use the machine free 'cuz I bought gas there (~ $0.35 per gallon ;-). Also, there were NO Engine Covers, and you could access all EIGHT plugs easily in 10 minutes or less.

I even changed a broken valve spring in less than an hour at a gas station just off an I-81 ramp at 10 o'clock on a Sunday Night one time, as I had a replacement spring, air fitting and necessary tools. Station operator was kind enough to let me use his service bay and compressor air hose (which was all I needed ;-). It would have taken several days on a DOHC engine.

Times, Complexity of Mechanical & Electrical Systems, attitudes, business models, and technical knowledge have changed. Electric Cars will be the next "Culture Shock" to shade tree mechanics.
George

[nsjames]

Originally Posted by gbalthrop

My experience with 3/2007 328xi N52KP:
I bought the car at 130,xxx miles. It ran perfectly, NO SES or Fault Codes. Drove it like I stole it for ~ 2 weeks. THEN when accelerating at WOT in 1st & 2nd, to ~ 6,000 RPM shift-point, SES came on, ran VERY rough at cruise or idle for ~ 60 seconds, then SES went out and normal performance returned.

AFTER that happened twice, and I had a single "Misfire" code (say P0301) on each occasion, I ordered a new set of plugs and a single Bosch Coil (just in case). Changing plugs to proper .040" gap Bosch Platinum fixed issue and NO SES or Misfire Code in last 4+ years since (I still drive it like I stole it).

Upon removing OLD Plugs, the following findings:
1) Plugs were Platinum FR7NPP332 Bosch plugs with "BMW" logo; presumed ORIGINAL; further evidence that original: VERY difficult to get coil boots off plugs;
2) After several MILLION explosions, the plug gap had increased from original .040" gap (N52 engine) to .055" - .060" gap;
3) The plugs were otherwise in good shape, as were the coil boots; no oil, no carbon;

My interpretation of that data:
a) over 10 years and 130,000 miles, the plug gaps had enlarged as indicated, due to electrode erosion and/or cumulative explosive force on negative pin.
b) NO "Misfire" at sedate operation, but eventually when coil had to provide spark 50 times per second at 6,000 RPM, it couldn't "Reload" & produce enough voltage FAST enough to have spark jump the enlarged gap.
c) I probably COULD have just "Re-Gapped" the original Platinum Plugs to .040" and driven ANOTHER 130,000 miles, but I'm NOT THAT CHEAP (but CLOSE).

Current plug price for Bosch Platinum FR7NPP332, $7 at Autohaus:
https://www.autohausaz.com/pn/FR7NPP332

As for plugs on "older engines" needing to be changed in 20,000 miles, I'll show my "Dinosaur" credentials:
In 1967, I had a 427 Corvette. It had an EARLY Electronic Ignition. It had a 10.5 or 11:1 Compression Ratio (don't remember which), and burned Premium LEADED fuel. Any time I wanted to Auto-cross it I would have to change the plugs. They fouled in ~ 200 miles.

The good news is that in the 60's, many gas stations had "Sparkplug cleaning machines" that would decarbonize plugs by sand-blasting, and in my small town, I could use the machine free 'cuz I bought gas there (~ $0.35 per gallon ;-). Also, there were NO Engine Covers, and you could access all EIGHT plugs easily in 10 minutes or less.

I even changed a broken valve spring in less than an hour at a gas station just off an I-81 ramp at 10 o'clock on a Sunday Night one time, as I had a replacement spring, air fitting and necessary tools. Station operator was kind enough to let me use his service bay and compressor air hose (which was all I needed ;-). It would have taken several days on a DOHC engine.

Times, Complexity of Mechanical & Electrical Systems, attitudes, business models, and technical knowledge have changed. Electric Cars will be the next "Culture Shock" to shade tree mechanics.
George

I know people that still run copper plugs because a copper plug is still the best performing plug.

I don't like changing plugs all the time and they erode real fast in a high energy ignition system. platinum plugs seem like the best option for performance/longevity.

[The Nightman]

NGK publishes the life of their plugs. Here are the N52 plugs:

1. 12120032137 = NGK ILZFR6D11 1208 (Laser Iridium): 100k miles - iridium center, platinum ground, JIS height
2. 12120035915 = NGK PLZFR6A-11S 5987 (Laser Platinum): 90k miles - platinum center, platinum ground
3. 12120037663 = NGK LZFR6AP11GS 95712 (Laser Platinum): 40k miles - platinum center, nickel ground
4. 12120032138 = BOSCH FR7NPP332 (Double Platinum): no specified life - platinum center, platinum ground. 90k miles if similar to NGK PLZFR6A-11S?

Alternatives:
5. NGK LZFR6AP-11GS 94122 (Ruthenium HX) - 60-120k miles - ruthenium center, platinum ground
6. NGK LFR6AIX-11 6619 (Iridium IX) - 50k miles - iridium center, nickel ground

FWIW, I replaced my factory Bosch FR7NPP332 plugs at 60k miles as preventative maintenance and the engine ran noticeably better with new spark plugs (NGK LZFR6AP11GS). A simple re-gap might've worked too but given how cheap plugs are, it's not a bad idea to change them sooner rather than later. Excessive gaps or poor plug conditions can damage the ignition coils.

[Mosaud1998]

I did mines at 72k miles. Since I brought them from FCP I'll be changing them out again after 50k miles

[Gamb1t]

I change the plugs at 50k km. It's not too hard with inline engines. With my current mileage accumulation rate, that's about 12 years from now.

[M40i4me]

I went 110,000 miles on my OEM set, but pushed them too far. I just started to get a slight miss and when I changed them they perfectly grey, but worn out! Changed them again at 170,000 miles and decided to change out the OEM coils as well even though I did not have any misfiring.

[Jesda]

Every 100k just replace the plugs, valve cover gasket (and maybe valve cover too), intake manifold gaskets, valvetronic motor gasket, eccentric shaft sensor and gasket, crankcase breather hose, belt, and oil filter housing gasket all at once.

Make a weekend out of it and don't worry about a thing for 100k. It's a lot but if you've already got everything else apart then it's not so terrible to do all at once.

You might have to do the water pump and thermostat but there isn't much labor saved by doing those at the same time.

I have a late 2007 N52 with NGK Iridium plugs.

[John 070]

I did mine at 40k and didn't see any benefit. Actually, I've never seen any benefit on any car where I've changed plugs. I don't know if my CBS has changed but my was set for 45k, I saw above someone said turbo is 60k? I'm stock N54 not PPK. Also, I went Bosch to save $3/plug. Heck that's almost an Andy Jackson. I remember buying a SK locking extension for the job and it was too long for #5. I've since gone on amazon to get a set of I wanna say Neiko and what junk, don't lock out of the package, sockets fall right off.

[E90Menace]

Swap out every 25K

[gbalthrop]

Originally Posted by Efthreeoh

I replace gaskets when they begin to leak.

I AGREE! If it "Ain't Broke":
1) Do something else;
2) Have a beer;
3) Float a boat, or WHATEVER

My 2007 328xi N52KP has not leaked ANY oil from anywhere other than seepage at rear of Oil Sump, in the four+ years I've had it. Don't know WHAT prior owners did, or if OFHG & VCG are original.

I can't help but wonder if OVER-tightening Oil Filter Cover, or "ham-fisted" cover removal contributes to OFHG leak. I've done ALL my own work under hood (bonnet ;-) and always just tighten Filter Cover to "Hand-Tight". The Cap o-ring is the seal, and the cap is NOT going to loosen by vibration.

My 33-year-old XJ-S has NEVER had the cam covers off, at least in 17+ years I have owned it. It doesn't leak a drop of oil. Conventional Steel Bolts (NOT "single-use" T-T-Y bolts) can be "snugged-up" as a gasket shrinks from compression, to prevent/ reduce seepage. Can't do that (safely) on Oil Pan, but CAN on Tranny pan and OFH (steel bolts into aluminum head).

ANYONE taken the time to think about OFHG leaks and have a THEORY?
George

[hassmaschine]

I'm sure people have, but it seems like the consensus is the OFHG material quality is poor. These things turn into hard, brittle plastic after a while. With some BMW gaskets, there's no avoiding leaks because they aren't made of the right material to begin with (I'm looking at you, N62 alternator bracket gasket of doom).

I'd bet mine was replaced before I got the car, but there's no records of it, and it would have been 10 years ago by now. In any case, it doesn't leak, so I'm not touching it..

[hassmaschine]

Originally Posted by E90Menace

Swap out every 25K

Or, just light your money on fire directly. It's just as effective!

[marvinstockman]

It is a good idea to change the plugs at the required interval, even if they are not missing, as you definitely don't want the plug threads to seize to the block.

[Jesda]

Originally Posted by Efthreeoh

I replace gaskets when they begin to leak.

The VC and OFH gasket fail at a fairly regular interval. It's better to follow a schedule and save time if you're already in there working on something else.

[E90Menace]

Originally Posted by hassmaschine

Or, just light your money on fire directly. It's just as effective!

I drive 25K per year, so once a year swap them out, and every 50k I swap out plugs!