Went to buy plugs today............

[Craig Wright]

.............at Advance Auto Parts.

"We don't stock the Bosch Super. I can order them for you..........I'll have two on Tuesday and the other four by next Friday."

He said this with a straignt face and then added that I could upgrade to the platinum +4.

Said thanks, but no thanks, and walked out the door.

[BMWCCA1]

Well, if his price was good, I'd order them as spares and not care when they came in.

[Jehu]

BMW has switched to NGK Plugs....

[BMWCCA1]

BMW has switched to NGK Plugs....That's a pretty broad statement, particularly when we're talking M30 engines, not V8s. AFAIK, on later engines BMW still uses two suppliers for plugs, as they do for many parts so they don't get hung-up during strikes or shortages. In the days of the M30, they only used Bosch and I believe that's still the only plug recommended.

[Craig Wright]

I'll just order the "tune up" kit from BMA. I did not think I'd have to order from a local shop.

[Jehu]

That's a pretty broad statement, particularly when we're talking M30 engines, not V8s. AFAIK, on later engines BMW still uses two suppliers for plugs, as they do for many parts so they don't get hung-up during strikes or shortages. In the days of the M30, they only used Bosch and I believe that's still the only plug recommended.


Yah I just meant I called a Local dealership to see what plugs they'd supply for my 540 and they quoted an NGK plug. When I asked why they said BMW had made the change to NGK so I assumed it was across the board.

[BMWCCA1]

I think you'll find BMW has a part number for both Bosch and NGK for your car. Perhaps your dealer only stocks one of them. Make sure if you're paying BMW-Dealer prices for spark plugs that you're getting plugs that say "BMW" on the plug. I remember a recall on Bosch plugs many years ago that applied only to specific plugs but not to the ones made for BMW with their name on them even though they were supposedly the same type and heat range. Maybe you do get your money's worth when you buy at the BMW dealer.

[attack eagle]

it is ridiculous that the dealer wants $8 a plug for coppers, an d local places only have platinum multiprong garbage.

[BMWCCA1]

Well actually, at my local dealer they're at $6 for the silver Boschs for my E28 535is and about the same for the NGKs or the Bosch for the '95 M50TU 525i. Not that that's cheap but it is the correct plug and I don't pay shipping (tax, yes).

Autolites shouldn't cost more than $3 each. ;)

[Jon K]

NGK makes a superior plug. There are NGK replacements for that plug.

[BMWCCA1]

NGK makes a superior plug. There are NGK replacements for that plug.For what plug? Heck, Autolite makes what they call a replacement for any plug, and I'm sure NGK lists a cross-reference for just about anything, too. But there are some cases where a Bosch just works better. I use nothing but NGK BP5ES in my 2002tii's and my 2.3L 2002, but nothing seems to work as well as the OE Bosch in my '87 535is or any of my BMW air-head motorcycles. YMMV

[Gene in NC]

In Raleigh Leith BMW wanted $11.xx for Bosch W8LCR. Had called all the local and chain parts houses and not one had W8LCR in stock, most didn't even have in their computers and only one would order for $4.xx and a four day delivery.

Advance has a mystery Bosch "standard" listing not stocked for $2.xx, suspect this may be W8LCR. Will try this and report. Have three M20s and one M30 that need plugs, including two '89 525. Will try Bosch in one and NGK in the other.

I went for the NGK ZGR5A for $1.98 from Advance this time, shipped in overnight by 7:30 am next day, and did the whole thing over the phone. Advance is most convenient for me, and seems to be really sharpening up their overnight order process. Always seems to have one Spanish speaking female who may know Spanish but doesn't know s... about parts.

[Jon K]

For what plug? Heck, Autolite makes what they call a replacement for any plug, and I'm sure NGK lists a cross-reference for just about anything, too. But there are some cases where a Bosch just works better. I use nothing but NGK BP5ES in my 2002tii's and my 2.3L 2002, but nothing seems to work as well as the OE Bosch in my '87 535is or any of my BMW air-head motorcycles. YMMV

Autolite makes a crappy plug - I've used them for a bit. NGK makes a superior plug across their entire product range. I dunno whats hard to understand - I would take any NGK plug over any Bosch plug and that's from experience.

[Gene in NC]

M20 plug test Bosch W8LCR vs NGK ZGR5A?

Would in make any sense to run both in same engine as a test. 1,2,3 vs 4,5 6, or 1,3,5 vs 2,4,6? Should at least rule out other variables between two different engines?

[BMWCCA1]

Autolite makes a crappy plug - I've used them for a bit. NGK makes a superior plug across their entire product range. I dunno whats hard to understand - I would take any NGK plug over any Bosch plug and that's from experience.
I used Autolite only as an example of how cheaply one could buy plugs if one just didn't care about anything else. But actually many oil-head BMW motorcycle owners swear by the cheap Autolites for smoothing out the peakiness of the BMW DME ignition. They're often recommended for bikes with bad surge tendencies. I've also pulled lowly Autolites out of M50-engined cars I've bought and found they actually perform well and seem to even get better fuel economy. I still don't use them because I always felt my customers were expecting BMW OE parts. It is possible that Autolites share a similar characteristic as much-loved NGKs in that they seem to operate over a broader heat-range than Bosch in some cases, making them more forgiving against sooting-up in certain applications. There are still certain BMW models I won't run on anything but Bosch, and some in which I won't consider anything but NGK. But then my BMW experience may be a bit broader and over a longer-term than yours! ;)

[BMWCCA1]

M20 plug test Bosch W8LCR vs NGK ZGR5A?

Would in make any sense to run both in same engine as a test. 1,2,3 vs 4,5 6, or 1,3,5 vs 2,4,6? Should at least rule out other variables between two different engines?Great idea, and be sure to run different tires on the same axle just to test those, too. Perhaps different brake pads on each side, and always mix brands of oil in the crankcase, too. Oh yeah, try one brass-base bulb in one of your E28 brake lights, too. Different wheels maybe? And I'd paint half the hood with different paint, too, while you're at it. Sheesh, Gene, I hope you were kidding.

[Jon K]

But then my BMW experience may be a bit broader and over a longer-term than yours! ;)

Longer-term perhaps, but I am not sure I'd consider it broader given the nature of what myself and my friend do with our BMWs.

Autolites aren't that cheap in the grand scheme of things - they cost about $2.49 - $2.79 each here in PA locally. In the same store (advanced), the NGK BKR6ES and BKR7E cost $1.77 ea and we've run over 600 hp and 600 ft lb of torque on that plug. Over that, we use an 8 temp NGK plug.

When you're running 30 psi of high-volume boost in an engine you tend to learn real quick which spark plugs cut the mustard or not. Bosch plugs are misfire Kings.

[BMWCCA1]

Well, Jon, you wrote:
I would take any NGK plug over any Bosch plug and that's from experience.I'm simply saying your experience may not correlate with others on this site or with all other BMW owners. What you've found in your boosted-use isn't sufficient to say in all applications an NKG is superior to Bosch. Your experience may be with boosted E34s but mine also includes 12hp 1-cylinder BMWs, 36hp twin-cylinder BMW bikes, and other BMWs, stock and modified, spanning over fifty years of production and 35-years of driving. I'm not saying that in your limited application you've highlighted for us that you're wrong, but you're saying that in any application in which anyone finds that Bosch works better that they're wrong. You spoke in the absolute and yet your empirical proof is far from that. I like, and use, NGKs, too, but I don't use them in all applications or even in every BMW I own.

[Jon K]

I am talking gasoline fueled BMW automotive engines that are commonly driven today as well as yesterday. I have worked on everything from stock M10s to turbo M10s to stock S38s to turbo S38s, M50s of both natures, M52s, S52, M30's, M20's, even some M106 cars and I had the joy of working on M88's as well. M60B30s, B40's, S54's, etc. The motors all range from low compression turbo builds to high compression NA builds to daily driving commuters in between. A motorcycle engine is different from a car engine on many fronts and spark plug application is not the chief difference - heads, pistons, etc., are all much different.

In automotive use spark plugs, I will use an NGK plug any day over a Bosch plug - I have personally bought over thousands of dollars of spark plugs for my and the cars I've tuned/worked on and wouldn't put a single other plug in our engines. I've had Bosch suck the gap down, over heat, porcelain crack, ground strap break off, etc. I have not had one single issue with NGK. Bosch manufacturing is not what it once was, and I don't believe it has been for a very long time. I am a fan of NGK V groove race plugs (BKR6E, BKR7E, BKR8ES...etc) in standard copper electrode with single ground strap. Gappable, reliable, and lasts longer than a spark plug should be in a performance engine.

And on top of it all, theyre cheap as ****. $1.77 ea to plug my car 1 or 2 steps colder with a V groove race plug? Sold!

I am not a fan of iridiums either.

[ryan roopnarine]

going to chime in here with an autolite success story for the m50. comparable performance to the oem bosch 2 ground plug for the car. no improvement in idle, so to speak. long story short, needed plugs, were owed plugs by advance, got the autolite because no one else could get the bosch without ordering them. no, i didn't go out of my way to try to put autolites in my car, but they are serviceable replacements. here in flor-ada they are about 1.77 each and available everywhere. you just have to adjust the gaps....

jon, how do you get advance to get you specific ngk plugs? do you just go in and ask for the model number? I know that asking them for the model specific plug won't work in that regard.

[Bill R.]

As Phil stated and i agree I've had no problems with the Bosch Supers but plenty of problems with bosch platinums aftermarket.

My current favorite plug is the NGK iridiums, simply the best plug i've used yet in mine and customers cars. Overall i do have better results with ngk plug over bosch, so i went from being a diehard bosch fan in the early 70's, Back in 72 when we first started seeing ngk plugs in datsuns and toyota the common story was that NGK stood for No Good Kind... we started using them in the aircooled VW's and Porsches at our shop because the price was right back then. Gradually we noticed that the quality was getting better and better.

Hardly ever saw a bad plug out of the box like we did with some of the Bosch Supers and even the Silber plugs, so over the last 35 years or so I've weaned myself off of Bosch plugs and pretty much use NGK on my own stuff. The iridiums are turning out the be the best thing since sliced bread for me. Anytime i don't have comebacks I'm happy.

As a side note blending in the spark plug thread and the engine cleaner thread... I have a customer with a 99 e39 528i and it kept misfiring on cold startup and throwing a multiple cylinder misfire code cyl2 and 3 occasionally, typically cyl 2 though. I went through all the usual m52TU stuff. Replace the tube from the pcv hose, replace hose ,replace crankcase ventilation valve, replace dipstick hose etc etc.. Nothing helped, checked coils , insulators, moved coil to a different cylinder, checked injector pulse width, checked injector pressure drop on each cylinder and so on. Checked everything. Only thing is i could not get the spark plugs out , they were seized in... I scanned system repeatedly and long term fuel and short term fuel were coming up fine for each bank. Finally i had the customer take it to the dealer to diagnose on the GT1 or whatever they're using now.

He brings it back and they sold him a new coil, then pulled it off when they found it made no difference basically came up with nothing that i hadn't seen already. They tried to pull some plugs and found all of them seized like i had. Customer was quoted 4k dollars to Rand R the head, not including repairing spark plug threads, just head gasket and materials. Needless to say he brought it back to me and said to go ahead and remove the plugs if i can, he's willing to pay for removing the head if i have to . I didn't think i'd have to , figure i could use a sav-a-thread and a small vacum and borescope to remove and chips that fell inside

As a last ditch resort i had seen some posts regarding pumped up lifters on the m52TU and some people on iatn had good results using engine flush and this got rid of the multiple cylinder misfire.... So i bought some of the KW flush which is a crc product. I've always had good results form crc stuff....So i use this flush on his motor which has had synthetic for the life of the car changed at bmw's outrageous milage specs for most of its life. In the past i noticed on an oil change his oil usually turned black right away

. I used this KW flush and when i opened the oil filter housing to change the element there was about 2 inches of muck in the bottom of the filter housing.....I'd never seen this before on his car and was suprised the flush moved this gunk into the filter... Did the flush , put fresh synthetic and a filter in and ran it, same results , it wasn't a pump up lifter sticking.... So then i started to attempt to get the plugs out, and they had that sickening feel to them , where you start to remove them and they come about 3/4 of a turn and then get real tight and won't budge under normal pressure....I thought about it and then squirted about 3 ounces of PB blaster in each plug hole with the plug turned about 3/4 to 1 1/2 turns out in each hole and let it sit for 8 hours, then came back and ran then in a little then back out , eventually by running the in and out and spraying more pb blaster i got them all out without stripping any of them. They were the bosch factory 4 electrode plugs and they looked to be in good condition, but just for the heck of it , and since i could get the NKG iridium cheaper than the OE, Bosch plugs, I put the iridiums in, with a little antiseize even though i don't like antiseize generally... on this motor i wanted no more seized plugs. It started and idled beautifully , no more misfire codes , no more misfire and no more DME shutting off the injector.. Also i use a number of Autolite double platinums on many cars where the customer wants a double platinum plug. For 3.99 i've had good results with them and not a failure yet Anyway after using the KW engine flush and following the directions his oil has stayed clean for a couple of weeks, looking at the dipstick... It never did this before , used to get dark on the dipstick within a day or so.

[Jon K]

Interesting story Bill and when I first got into this stuff I had been using bosch too - but when I had some issue with bosch plugs I tried autolites in a pinch and they worked and worked better than the Bosch. Then I went to NGK in my and a few cars... then looked at what other people were running...NGK...hm... Ok - so we dyno cars with gobs of power, throw the NGK coppers in there and never flinch!

Ryan - I get the Advanced part number for instance the plug I use is 6097 advance stocking number, its a 1 step colder plug resistor w/ v-groove. Some plugs you can't get but they usually have all of them in stock.

[Ross]

It warms my heart to hear that even the pros go around banging their heads on the wall sometimes. Any thoughts on my 530 Bill? I'm running out of ideas and wincing at the thought of a compression check on a 100k nik. motor.
Congrats on the patience to get the plugs out. Anything that smells as bad as PB Blaster has to work well.

[Jon K]

.... I <3 PB Blaster smell.... is that wrong?

[philbyil]

I just replaced the Bosch P+4's on the GQ. They had 10k on them without a problem...nice colour too :) !!
I replaced them with Bosch Stock #4303's (2 electrode) which I got from Autozone along with a new battery. With 400 miles on them now I can say they work just great....the car idles perfectly and revs easily upto redline (and beyond - I have a JC chip!) without a hiccup. Weather is VERY hot down here and even when running in 100F temps, no problems at all. Mileage showed 26.4 in, around, up and down the hills and twisties :)

I only speak as I find...



.............at Advance Auto Parts.

"We don't stock the Bosch Super. I can order them for you..........I'll have two on Tuesday and the other four by next Friday."

He said this with a straignt face and then added that I could upgrade to the platinum +4.

Said thanks, but no thanks, and walked out the door.

[Bill R.]

climate as you , plus 110F frequently.... You have a pretty steady record of 26.4 for your mileage with the bosch's, You can get the ngk iridiums for less than 7.00 each, Just for grins why don't you try them next time you change plugs, Under my temps here i can verify a noticeable mileage increase and every car i've put them in runs and idles better, even my previa which had new A/C delco rapidfires in it when i changed to NGK iridiums. I'm curious to see if you get the same results that i get. I only have customer feedback which isn't always accurate.




I just replaced the Bosch P+4's on the GQ. They had 10k on them without a problem...nice colour too :) !!
I replaced them with Bosch Stock #4303's (2 electrode) which I got from Autozone along with a new battery. With 400 miles on them now I can say they work just great....the car idles perfectly and revs easily upto redline (and beyond - I have a JC chip!) without a hiccup. Weather is VERY hot down here and even when running in 100F temps, no problems at all. Mileage showed 26.4 in, around, up and down the hills and twisties :)

I only speak as I find...

[philbyil]

Howdy Bill, nice to see you are still giving wisdom on the board mate :).
Hope all is well with you....

The mileage I gave you was for thrashing around the Hill Country with the new ones. The +4's gave me 29's on Interstates at 55/60ish but I do mostly thrashing around the twisties in the GQ and I get low 20's!!!

I'll give the NGK Iridiums a try at the next plug change for the GQ. I am about to change the plugs on my R1100R and the guys on the BMW motorcycle boards heavily recommend AC XP3923's as a replacement for the NGK's, so am trying them to see what, if anything, they have to offer :D

All the best




climate as you , plus 110F frequently.... You have a pretty steady record of 26.4 for your mileage with the bosch's, You can get the ngk iridiums for less than 7.00 each, Just for grins why don't you try them next time you change plugs, Under my temps here i can verify a noticeable mileage increase and every car i've put them in runs and idles better, even my previa which had new A/C delco rapidfires in it when i changed to NGK iridiums. I'm curious to see if you get the same results that i get. I only have customer feedback which isn't always accurate.

[BMWCCA1]

I am about to change the plugs on my R1100R and the guys on the BMW motorcycle boards heavily recommend AC XP3923's as a replacement for the NGK's, so am trying them to see what, if anything, they have to offerI believe you'll find that's an Autolite number, not an AC/Delco part. Probably the same one recommended for the M50TU 525i.

[Bill R.]

NGK lazer iridium plug. Except the NGK uses an iridium center electrode and the autolite uses a platinum iridium enhanced center electrode For the slight difference in price i'd stick with the NGK iridium instead. Typical life estimates on the iridium plug is around 100k miles. A number of the newer toyotas and lexus that i work on have them in them from the factory and iridium plugs are the only plugs used in the honda hybrids and the toyota hybrids.






I believe you'll find that's an Autolite number, not an AC/Delco part. Probably the same one recommended for the M50TU 525i.

[philbyil]

DUH! Yup! UR correct....I actually meant Autolite...had a brain fart but I am excused coz I'm over 60 :D


I believe you'll find that's an Autolite number, not an AC/Delco part. Probably the same one recommended for the M50TU 525i.

[BMWCCA1]

I am excused coz I'm over 60 :DAnd I'm closing in on you. In less than five years it will be your turn to remind me . . . of something . . . I forgot what it was though.