When to replace spark plugs???

clairvoyant · 09-05-2009, 11:36 AM

At what mileage do you replace spark plugs?
I don't track it but drive "spirited" once in awhile (running Procede Rev 2, catted high flow downpipes, and dual cone intake).

Thank You

cstmx_ryder · 09-05-2009, 11:54 AM

I replaced mine at about five months ago, I've had the car for about two years now.

scottp999 · 09-05-2009, 01:15 PM

I'm at 11k miles, been tuned since 700 miles. Full bolt on mods. I will probably wait until next spring. Will probably be around the 15k mark, but the car will be 3 years old at that point.

jpsimon · 09-05-2009, 01:24 PM

30k miles, haven't changed em yet but haven't had a reason to. will probably change em sooner than later though no matter what.

doofus2 · 09-05-2009, 01:30 PM

Quote:

Originally Posted by clairvoyant

At what mileage do you replace spark plugs?
I don't track it but drive "spirited" once in awhile (running Procede Rev 2, catted high flow downpipes, and dual cone intake).

Thank You

There was a recent surge in folks with tunes posting about their plug replacement experience. Most folks posting had rather worn, but otherwise normal looking plugs.

My conclusions after reading those posts (and replacing my own tune-worn plugs) are:

15k miles on a tune erodes the electrodes enough to warrant replacement.
Under these conditions, plug replacement can net up to 25 lost horsepower.

Of course, YMMV.

enrita · 09-05-2009, 02:56 PM

I would highly recommend to everibody running a tune to change them every 10-15K miles. Mine after 18k were completely gone.

Perfectus · 09-05-2009, 04:18 PM

What's BMW recommended replacement interval?

stressdoc · 09-06-2009, 11:23 AM

Lowered from 60k to 45k.
BMW Perf kit requires new plugs. So something is going on in regard to plugs wearing out.

hotrod182 · 09-06-2009, 01:10 PM

I replaced my plugs at approx 17000 miles. 300+ 1/4 mile runs, on 91 octane, map#7, and quite a few runs on racing fuel. They looked fairly worn, but I don't seem to have gained any measurable horsepower FWIW.

BMWfan07 · 09-25-2009, 09:03 AM

Quote:

Originally Posted by stressdoc

Lowered from 60k to 45k.
BMW Perf kit requires new plugs. So something is going on in regard to plugs wearing out.

At 45k, is the spark plug replacement covered under the free maintenance program? My 335 has 44k now.

5soko · 09-25-2009, 10:58 AM

Quote:

Originally Posted by hotrod182

I replaced my plugs at approx 17000 miles. 300+ 1/4 mile runs, on 91 octane, map#7, and quite a few runs on racing fuel. They looked fairly worn, but I don't seem to have gained any measurable horsepower FWIW.

Interesting! I forgot to ever ask you hotrod if replacing your plugs yeild you anything in the 1/4 with your timing tools?

I guess the answer is no.

wsybert · 09-26-2009, 08:02 PM

Quote:

At 45k, is the spark plug replacement covered under the free maintenance program? My 335 has 44k now.

They are covered. Mine has 49k, and they just did oil service and plugs, under free maintenance.
Bill

roadkillrob · 09-26-2009, 08:55 PM

Quote:

Originally Posted by stressdoc

Lowered from 60k to 45k.
BMW Perf kit requires new plugs. So something is going on in regard to plugs wearing out.

Does anyone know if the performance kit replaces the plugs with the same plugs as stock or if they are changing heat ranges?

MFKN3 · 10-03-2009, 08:38 PM

I changed mine yesterday. No real reason to, other than keeping her in top condition as she is tuned.

Car is just over 2yrs old and has 28,000km. The plugs generally looked ok, except cyl 1 looked a bit gunked up and cyl 5 looked a bit worn.

dborgendale · 10-29-2024, 08:53 AM

I find if very curious that BMW in Europe recommends a sparkplug change every 30,000 KM where as in the US the recommendation is every 30,000 miles which is closer to every 50,000 KM. Does anyone have an idea as to why this difference exists?

swellengear · Today, 12:04 AM

15 years late to the party. lol

09-05-2009, 11:36 AM	#1
clairvoyant Major 83 Rep 1,032 Posts Drives: Bavarian Manure Wagon (BMW) Join Date: Oct 2007 Location: 45°19′20″N, 75°50′0″W iTrader: (5) Garage List 2007 335i [5.24]	When to replace spark plugs??? At what mileage do you replace spark plugs? I don't track it but drive "spirited" once in awhile (running Procede Rev 2, catted high flow downpipes, and dual cone intake). Thank You
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09-05-2009, 11:54 AM	#2
cstmx_ryder Colonel 171 Rep 2,875 Posts Drives: A metal box with a roundel Join Date: Jul 2007 Location: Portland, OR iTrader: (2)	I replaced mine at about five months ago, I've had the car for about two years now. __________________ '08 AW E90 335i PROcede V5 \| BMS DCI \| RR DPs \| ETS FMIC \| FORGE DVs \| Stett CP \| Vanguard \| PSS10
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09-05-2009, 01:15 PM	#3
scottp999 Brigadier General 133 Rep 4,764 Posts Drives: 4runner SR5 Join Date: Mar 2007 Location: MD iTrader: (2) Garage List 2007 BMW 335 [9.00]	I'm at 11k miles, been tuned since 700 miles. Full bolt on mods. I will probably wait until next spring. Will probably be around the 15k mark, but the car will be 3 years old at that point.
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09-05-2009, 01:24 PM	#4
jpsimon Team Zissou 3136 Rep 10,200 Posts Drives: 2022 AWD M3 Comp - SMB Join Date: Dec 2006 Location: CT iTrader: (7)	30k miles, haven't changed em yet but haven't had a reason to. will probably change em sooner than later though no matter what.
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09-05-2009, 02:56 PM	#6
enrita Major General 161 Rep 7,377 Posts Drives: 335i - Big turbos Join Date: Sep 2008 Location: Italian in Sweden iTrader: (0)	I would highly recommend to everibody running a tune to change them every 10-15K miles. Mine after 18k were completely gone. __________________ 07 335i AT - MOTIV 750 - MHD E85 BMS flash - BMS PI - JB4G5 - Okada Coils - NGK 5992 Plugs - Helix IC - Snow Stg. 3 - Stett CP - Custom midpipes with 100 HJS Cats - Bastuck Quad - PSS10 - QUAIFE LSD - BMS OCC - Forge DVs - AR OC - ALCON BBK - M3 Chassi - Dinan CP - Velocity M rear Toe arms - Advan RZ-DF - LUX H8 - Level 10 AT upgrade
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09-05-2009, 04:18 PM	#7
Perfectus Major 35 Rep 1,252 Posts Drives: e92 335i/F10 528XI Join Date: Jun 2009 Location: NOVA/MD iTrader: (10)	What's BMW recommended replacement interval? __________________ 2012 528XI Saphire Black Stock for now 2007 e92 335i - Monaco Blue Injen DCI w/ Cyba Scoop - M-Tech Rear - ///M3 Rear Lip Spoiler - ///M5 SMG Shift Knob & iDrive Knob - BMW Performance Hand Brake - BMWCCA Member
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09-06-2009, 11:23 AM	#8
stressdoc Moderator 652 Rep 10,863 Posts Drives: BMW i8; Toy 4runner TRD pro Join Date: Jun 2005 Location: Waco TX iTrader: (0)	Lowered from 60k to 45k. BMW Perf kit requires new plugs. So something is going on in regard to plugs wearing out.
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09-06-2009, 01:10 PM	#9
hotrod182 . 873 Rep 3,993 Posts Drives: 2023 i4 M50 Join Date: Dec 2006 Location: California iTrader: (0)	I replaced my plugs at approx 17000 miles. 300+ 1/4 mile runs, on 91 octane, map#7, and quite a few runs on racing fuel. They looked fairly worn, but I don't seem to have gained any measurable horsepower FWIW. Attached Images __________________ 2011 Alpine 335d M-Sport 12.34 @ 110.48mph 2019 i3s Terra, 2008 Black 335i Sedan. 11.11@ 129.47 mph 2008 Monaco Blue JB3 2.0 335i Coupe. 11.33 @ 132.77 mph, 60-130mph: 6.95 seconds 2023 i4 M50 11.48 @ 121.56mph, 3.43 0-60 (dragy)
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10-03-2009, 08:38 PM	#14
MFKN3 Colonel 132 Rep 2,224 Posts Drives: supercharged 4.4L stroker E92 Join Date: Nov 2008 Location: Australia iTrader: (2)	I changed mine yesterday. No real reason to, other than keeping her in top condition as she is tuned. Car is just over 2yrs old and has 28,000km. The plugs generally looked ok, except cyl 1 looked a bit gunked up and cyl 5 looked a bit worn.
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10-29-2024, 08:53 AM	#15
dborgendale Registered 0 Rep 1 Posts Drives: 2016 BMW 3r Join Date: Oct 2024 Location: Germany iTrader: (0)	Curious discrepancy I find if very curious that BMW in Europe recommends a sparkplug change every 30,000 KM where as in the US the recommendation is every 30,000 miles which is closer to every 50,000 KM. Does anyone have an idea as to why this difference exists?
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Today, 12:04 AM	#16
swellengear Private 137 Rep 75 Posts Drives: 2008 135i Join Date: Feb 2023 Location: Swellendam, South Aftica iTrader: (0)	15 years late to the party. lol
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