[WOT Bimmer]

I am going to be replacing my valve cover gasket over New Years, and I am contemplating replacing spark plugs and coils then:

http://www.ecstuning.com/News/BMW_E9...mpaign=newpost

I replace plugs about 50,000 ago, so I am probably due. Not sure about coils though. Should I go ahead and replace since I will have it all stripped down? Need someone to make this decision for me. :-)

[gryphun]

Depends on how many miles on the coils and if your vehicle has any problems? I replaced both plugs/coils when my bmw hit 94,000 miles, also cleaned the vanos solenoids while I was in there as well.

[Phil325i]

Originally Posted by gryphun

Depends on how many miles on the coils and if your vehicle has any problems?

+1

There are at least three schools of thought on this:

1. Replace all coils at a given mileage as a preventative measure
2. Replace a coil only when it fails
3. Once one coil has failed, it probably means more will follow, so replace them all.

I've just had a coil fail, and though there were no other fault codes, I decided to replace them all. I was amazed. Car runs so much better - smooth and with none of the minor hesitation issues I had previously suffered from.

Just my five cents...

[Wolf 335]

You got money to blow?...replace all why not.

[WOT Bimmer]

Originally Posted by Phil325i

+1

There are at least three schools of thought on this:

1. Replace all coils at a given mileage as a preventative measure
2. Replace a coil only when it fails
3. Once one coil has failed, it probably means more will follow, so replace them all.

I've just had a coil fail, and though there were no other fault codes, I decided to replace them all. I was amazed. Car runs so much better - smooth and with none of the minor hesitation issues I had previously suffered from.

Just my five cents...

I definitely have some hesitation issues. No misfires or rough idling, just some lag. Sounds like I should do it.

[TheSt|G]

With coils, just replace them as they fail. Modern BMW coils have a pretty long lifespan.

[Phil325i]

Originally Posted by TheSt|G

With coils, just replace them as they fail. Modern BMW coils have a pretty long lifespan.

Generally I'd agree with you. But I replaced only the failed coil and the minor, occasional hesitation issues remained. These only disappeared when the other five coils were changed...

And no, I don't have money to blow...but coils are only $25 each in the UK.

[roundle]

If you are over 90K miles, I'd replace plugs and coils while you have the cover off.

[TheSt|G]

Originally Posted by Phil325i

Generally I'd agree with you. But I replaced only the failed coil and the minor, occasional hesitation issues remained. These only disappeared when the other five coils were changed...

And no, I don't have money to blow...but coils are only $25 each in the UK.

They should be ~$50. I suspect you bought OEM, which I definitely would not.

[Phil325i]

Originally Posted by TheSt|G

They should be ~$50. I suspect you bought OEM, which I definitely would not.

Oh why? And if so, what would you buy? I'm glad I went OEM because BMW have upgraded the design to one incorporating an integral heat shield. Non-OEMs I looked at did not have this.

[TheSt|G]

Originally Posted by Phil325i

Oh why? And if so, what would you buy? I'm glad I went OEM because BMW have upgraded the design to one incorporating an integral heat shield. Non-OEMs I looked at did not have this.

OEM=Not BMW

OE=BMW

Post a link to where you found them. If we can get OE coils for $25 per I'm changing them with every spark plug job.

[Phil325i]

Originally Posted by TheSt|G

OEM=Not BMW

OE=BMW

Post a link to where you found them. If we can get OE coils for $25 per I'm changing them with every spark plug job.

They were OE (manufactured by Delphi in a BMW box). Any UK BMW dealer will charge that price...

[TheSt|G]

Originally Posted by Phil325i

They were OE (manufactured by Delphi in a BMW box). Any UK BMW dealer will charge that price...

Link?

[Phil325i]

Originally Posted by TheSt|G

Link?

In the UK it doesn't work like that. You have to contact a dealer nearest you and visit thier parts department. Some give discounts to forum members. I doubt they would supply mail order to the US, and in any case the cost of shipping etc would probably offset any price saving.

[DickBlisken]

Originally Posted by TheSt|G

OEM=Not BMW

OE=BMW

Post a link to where you found them. If we can get OE coils for $25 per I'm changing them with every spark plug job.

What's the difference between OE BMW coils and OEM Bosch coils?

[TheSt|G]

Originally Posted by Nico87

What's the difference between OE BMW coils and OEM Bosch coils?

Well, for starters, Bosch doesn't make the BMW coils. But as always, the difference is that OEM parts are built to the supplier's standards, while the OE parts are built to BMW's standards. It's rare they match.

[DickBlisken]

Originally Posted by TheSt|G

Well, for starters, Bosch doesn't make the BMW coils. But as always, the difference is that OEM parts are built to the supplier's standards, while the OE parts are built to BMW's standards. It's rare they match.

Right, got it.

[Three_thirty_I]

Personally I think it all depends on whether you are willing to pay for a full new set. If you have one dodgy coil pack that is causing a misfire, then you can get away with just replacing that one coil pack, but typically this is a sign that the rest are soon to follow, as said above. The technology is getting better I suppose, but everything these days has a built in limited lifespan. My E46 had the older grey type Bosch coil pack which is susceptible to failure from possible valve cover gasket oil leaks, the newer Bosch (and BMW OE) part is the one piece black type which eliminates this problem. This is also the same part as the newer E90 N52 motors (from 04/06 iirc). Anyway, one of the original grey coil packs started to die on the E46, so had that one replaced and all was fine for about a year. The stumble at low revs returned and progressively got worse. I eventually just replaced all six (even the one that was replaced before was then replaced), and these were the newer improved design which is good. Comes down to peace of mind albeit at the cost of emptying your wallet a bit more. These were OEM Bosch parts, the dealer OE part was something like double the price, and that's probably double the typical US dealer price - where I am, the dealers seem to be intent on ripping us off, and that's also IF they have stock...

Originally Posted by TheSt|G

Well, for starters, Bosch doesn't make the BMW coils. But as always, the difference is that OEM parts are built to the supplier's standards, while the OE parts are built to BMW's standards. It's rare they match.

Can you elaborate (substantiate this)? BMW most certainly don't make the coil packs since quite clearly they have both the BMW and Bosch logos present, and the part numbers correspond (BMW has their part number and Bosch their own, these seem to be the same from what I have seen with OE and OEM parts). Other than the BMW logo being present, how is the OE and OEM part different? The general impression is that you are typically paying more for the added BMW logo for precisely the same part. Logically, if there are significant differences that would theoretically degrade operation and performance of a vehicle, then why are they being sold? Not arguing BTW, just trying to understand your statement.

[Phil325i]

In the UK at least, one advantage of buying OE rather than OEM is that BMW parts carry a two year warranty. Just had a NOx sensor fail for the second time in 18 months and BMW replaced it free of charge. Part alone was $450...

[TheSt|G]

Originally Posted by Three_thirty_I

Can you elaborate (substantiate this)? BMW most certainly don't make the coil packs since quite clearly they have both the BMW and Bosch logos present, and the part numbers correspond (BMW has their part number and Bosch their own, these seem to be the same from what I have seen with OE and OEM parts). Other than the BMW logo being present, how is the OE and OEM part different? The general impression is that you are typically paying more for the added BMW logo for precisely the same part. Logically, if there are significant differences that would theoretically degrade operation and performance of a vehicle, then why are they being sold? Not arguing BTW, just trying to understand your statement.

I was making a joke about Delphi being the primary supplier of coils.

The BMW logo on the parts isn't there to just add badge and cost, it is their seal that the parts meet their testing standards. From first hand expierence, it almost always plays out that the OEM part is inferior to the OE part. There are a number of shops that will refuse to use OEM parts as they don't want to be blamed for the failure.

Sometimes the variances are very apparent. OEM front half shafts on xi models generally last 5000 miles vs their 100,000 OE counterparts. Other times it is a more subtle degradation of performance, such has OE 135i plugs vs OEM 135i plugs.

The parts are being sold because they are cheaper and people will buy them solely for that reason. It doesn't help that 99% of the car community doesn't know the difference between OE and OEM thanks to shady marketing.

Originally Posted by Phil325i

In the UK at least, one advantage of buying OE rather than OEM is that BMW parts carry a two year warranty. Just had a NOx sensor fail for the second time in 18 months and BMW replaced it free of charge. Part alone was $450...

Also this. Though for post cat 02s I would use OEM Bosch as they don't contribute to performance either way and have free replacements as well.

[Three_thirty_I]

Originally Posted by TheSt|G

I was making a joke about Delphi being the primary supplier of coils.

The BMW logo on the parts isn't there to just add badge and cost, it is their seal that the parts meet their testing standards. From first hand expierence, it almost always plays out that the OEM part is inferior to the OE part. There are a number of shops that will refuse to use OEM parts as they don't want to be blamed for the failure.

Sometimes the variances are very apparent. OEM front half shafts on xi models generally last 5000 miles vs their 100,000 OE counterparts. Other times it is a more subtle degradation of performance, such has OE 135i plugs vs OEM 135i plugs.

The parts are being sold because they are cheaper and people will buy them solely for that reason. It doesn't help that 99% of the car community doesn't know the difference between OE and OEM thanks to shady marketing.



Also this. Though for post cat 02s I would use OEM Bosch as they don't contribute to performance either way and have free replacements as well.

Thanks, that is interesting. So in a nutshell, these OEM manufacturers are skimping on build quality but making the OE parts to a higher standard. That's very annoying! And again, just a pity that our local BMW agents pricing is basically focussed around extortion rather than being reasonable. And even the OEM parts supplier often try to follow this tactic, so one has to always check the pricing from both the agents and the OEM resellers.

We do also get a 2 year warranty on OE parts, but if DIY fitted there is a catch - they need to inspect the installation and diagnose the problem before they will replace the part if defective. So ultimately you are still out of pocket either way. It does often help to be friends with a particular dealer.

In general, it is amazing how things these days are made to last, by this I mean, last a limited amount of time. I have to take my watch in for a new battery typically less than a year, 10 months or less even, the batteries these days just don't last! I have an Isuzu double cab pickup, original Koito H3 halogen fog light bulbs lasted 7 years - fitted Hella Daymakers which just about managed to last a little more than a month, then fitted Osram Nightbreakers which lasted a few months before also failing! Only one of the original bulbs failed, whereas both of the new bulbs seem to fail almost at the same time. Again, the issue is that the OE part is crazy expensive compared to the other options available, anything from double the price to even more than 10 times the price! Crazy!

Food for thought...