Bosch Sparkplugs....experienced guru's help

[GoldenOne]

About a month ago is when my engine pooped out and after tearing down the engine I found that the electrode on one spark plug had broke off and pretty much destroyed the cylinder and the plug is pretty much smashed/stuck in the housing. Have any you experienced veterans ever heard, seen, repaired an engine where the electrode broke and caused significant damage? My buddy has seen three incidents of it, all bmws (though different engines), and all used Bosch plugs...

[winfred]

just about all of the trashed plugs i've found that something in the cylinder damaged the plug once i've torn it down to see the real story, the most common bosch plug failure i come across (besides the general shittyness of the platinums) is where the threaded bung is welded to the nut breaking along the weld and leaving half of the plug in the head, this is easy to fix as theres now a nice clean 1/4" or so hole to stick a extractor in and unscrew it

[misfortune]

winfred, what plug/wire combo for a 535i? I dun wanna start another new thread asking something that ha sproly been answered

[winfred]

W8LCR / 7509 bosch supers and oem wires, they are solid core wire and are about as good as it gets


winfred, what plug/wire combo for a 535i? I dun wanna start another new thread asking something that ha sproly been answered

[632 Regal]

busted electrodes and ceramic failure is usually caused by detonation/preignition (spark knock). Overheating and other problems lead to this catastrophic failure.

[wingman]

Yeah there are a million threads on plugs but going through them to find out exactly what you are after takes ages! I saw on ebay recently a bloke selling 'genuine' plugs. The plugs came in little 'BMW Original Equipment' boxes and clearly had NGK stamped on them! So I don't know. They use Bosch for everything but NGK for plugs? Doesn't make sense to me. OR it might prove my theory of ebay = fake

[ThoreauHD]

The NGK plugs and Bosch super's are comparable plugs. Bruno uses NGK in leiu of Bosch on his racingking.net site. Either going Bosch supers(1.50 per) or NGK(5.00 per) will fit the bill. I prefer to go bosch throughout where possible.

In the end, all I really know is don't use the platinums.

[Ausmpower]

Yeah there are a million threads on plugs but going through them to find out exactly what you are after takes ages! I saw on ebay recently a bloke selling 'genuine' plugs. The plugs came in little 'BMW Original Equipment' boxes and clearly had NGK stamped on them! So I don't know. They use Bosch for everything but NGK for plugs? Doesn't make sense to me. OR it might prove my theory of ebay = fake

BMW use EITHER NGK or BOSCH depending on the year model of the car.
I personally prefer NGK to Bosch through my racing/ turbo mod experience.

[genphreak]

The NGK plugs and Bosch super's are comparable plugs. Bruno uses NGK in leiu of Bosch on his racingking.net site. Either going Bosch supers(1.50 per) or NGK(5.00 per) will fit the bill. I prefer to go bosch throughout where possible.

In the end, all I really know is don't use the platinums.My 4-anode Plats are still running well- I'll be posting pics of them all soon so you can check em out after 18 months and 20,000km... :) Nick

[ThoreauHD]

It'll be nice to see what kind of buildup they have after 20K. On other engines, I found white powder on the electrodes. It also made the engine run a bit hot. I haven't ventured that route with my bimmer.

[Bill R.]

bosch produced the better plug but in the last 10 years or Ngk and denso have produced a much better plug and the quality on the bosch's seems to be far worse. I never seen the ceramic insulator crack and fall into the motor except on bosch. I have seen a couple of damage claims at the autozone commercial counter over engine damage caused by broken insulators eating up a cylinder. AT the time i just thought that the installers were meatheads and damaged the plug putting them in. But lately i've been seeing more and more posts on the internet regarding this on the bosch plugs and i have stopped using them unless the customer stipulates bosch.





BMW use EITHER NGK or BOSCH depending on the year model of the car.
I personally prefer NGK to Bosch through my racing/ turbo mod experience.

[winfred]

i think bosch in general has seriously fallen in quality since they started out sorcing manufacturing to other countrys


bosch produced the better plug but in the last 10 years or Ngk and denso have produced a much better plug and the quality on the bosch's seems to be far worse. I never seen the ceramic insulator crack and fall into the motor except on bosch. I have seen a couple of damage claims at the autozone commercial counter over engine damage caused by broken insulators eating up a cylinder. AT the time i just thought that the installers were meatheads and damaged the plug putting them in. But lately i've been seeing more and more posts on the internet regarding this on the bosch plugs and i have stopped using them unless the customer stipulates bosch.

[bfd]

For my 90 535i, 5spd, 107K miles, I use NGK ZGR5A, $1.99 each at Kragen/Checker/www.partsamerica.com

http://www.partsamerica.com/ProductDetail.aspx?mfrcode=NGK&mfrpartnumber=5839&parttype=960&ptset=A

[AngryPopTart]

I wish I would have known about this place when I first got my 525i. I have now read several experiences where people using the same plug (W8LCR) had the porcelin crack around the hot electrode and jack up the cylinder wall. It happened to me. :( The porcelin did break on #6 and now the plug in #6 always gets covered in thick, black gunk. But when I got the car, it had a burnt valve on #6 that I had to have fixed, so I'm afraid that it's due to a faulty injector that #6 busted a plug. Either way, I have 40% leakdown on #6, even though the compression is great and within a few percent from #1 to #6.

I also see alot of people talk about how cruddy the platinum plugs are in these engines. I wonder if they would work well if you used a non-resistor ignition wire setup. IIRC the plug ends on the factory harness are 5000 Ohms.

The thing about those platinums though, since electricity will always choose the easiest path to ground, it's really only going to be using one of the electrodes. If you look at the way the electrodes are designed, it's exactly like running a side-gapped plug. Since they act like it's supposed to create greater spark, I'm guessing they are relying on the design to act like a side-gapped plug, where the arc propogates up the face of the electrode. I mean really, look at the plug, remove 3 of the ground electrodes and you have a side-gapped plug with a very tall face. LoL!

[GoldenOne]

wow...this just brought back bad memories...


and angry pop tart??? wheres angry waffle at? or what did you do with angry pancake...

[John B.]

I've been running NGKs in my 535i for the last 3 years & just put them in our "new" 525i Touring. I will say the p/o of our Touring always ran the Bosch F7LDRC (Not F8?) & seemed happy with them. They still looked good after 36k when I tossed them but I've always had good luck with NGKs & have used them in my all my 2 & 4 wheeled vehicles since 1977.

[KenB]

Only spark plug failure I ever had was a Bosch in my VW over 30 years ago, insulating tip broke...never used them since.

[Jon K]

Not to beat a dead horse but I too have had experience with the modding aspect of these engines and prefer NGKs as well.

[ryan roopnarine]

I've been running NGKs in my 535i for the last 3 years & just put them in our "new" 525i Touring. I will say the p/o of our Touring always ran the Bosch F7LDRC (Not F8?) & seemed happy with them. They still looked good after 36k when I tossed them but I've always had good luck with NGKs & have used them in my all my 2 & 4 wheeled vehicles since 1977.

the number is f7ldcr, not f8. i have one sitting on my desk here. by 30k, my plugs are causing mild misfires.

[Yaninnya]

From my experience Denso are the best and NGK are quite close. I'm not touching Bosch spark plugs at all. In the past I had a lot strange problems with them (misfire, problems with cold start and overall quality problems mentioned by other users above). I'm not saying that it is bad company - most other products are superb.
Jan

[Jon K]

I can't imagine using spark plugs for 30k. I know they work, etc., but there is just something I cannot get past involving arcing electrodes for that long - $10 every 10k miles is fine with me.

[John B.]

I can't imagine using spark plugs for 30k. I know they work, etc., but there is just something I cannot get past involving arcing electrodes for that long - $10 every 10k miles is fine with me.

I change them every 15k on my 535i when I adjust the valves. No point in reinstalling a used plug. Our 02 Nissan Crewcab came with NGKs that were supposed to stay in for 100k but I changed them at 50k. Glad I did as they were a bitch to get out & every washer stuck to the head. Since 3 plugs are buried under the intake manifold in a noseeum position digging the old washers out of there was lots of fun!