2003 X5 6cyl > Why would I change the coil packs

[Meestahbig]

Hi - I have new spark plugs and am getting ready to replace them... my question is why would I also change the coil packs? Car runs good... has 143k miles. I am just changing the spark plugs bc they are the original plugs and I just felt like it was a good idea.

[Attacking Mid]

I don't change coils preemptively because they are long-lived and failure generally isn't something that will leave me stranded. The coils on my E46's M52TU are original from 1998 and have over 250K miles. However.... I don't let my plugs go 143K miles either, and old plugs put more stress on coils.

AM.

[Meestahbig]

Thanks... that was conveniently the answer I was looking for... coils either work or don't. I will change the plugs in a short while.

[andrewwynn]

Our two M54 x5 have about 170,000m iles each.

Started getting single cylinder misfires with fuel shutoff repeatedly. When it puts the car into limp home you can clear the error and still usually drive an hour or two before it repeats.

On wife's, two cylinders came back repeatedly I swapped those two coils out with donor coils from a different X5 and at the same time used some Lucas injector cleaner no related codes since.

Usually when a coil gets weak it will cause misfire on that cylinder and the car will set a cylinder specific code. I'll replace just that one coil as the rest may have 50 or 100,000 more miles in them.

I always have at least a wifi obd plug I can use with iPhone to reset a code and as mentioned usually a bad coil will still work once code is cleared to drive the car you can. "self tow" to get home.

Use only OEM grade plugs. I made the mistake of using otherwise and they lasted less than 1/4 the miles of the first set.

[Meestahbig]

thanks. yes, I have a code reader in one of the trunk side pods... I can read/clear the usual codes...

[andrewwynn]

I had spurious single cylinder misfire with fuel cut off on my car as well. Happened 3 times over almost a year. Changed plugs no misfires since. I was able to reset the MIL without even slowing down I already had the WiFi dongle within reach. It's kinda cool to have a herky jerky 5 cylinder engine come back to life like magic with a tap on the iPhone screen.

Someone on xoutpost was kind enough to donate some of their old coils when they did a preemptive replace of all. The donor coils are running strong.

Now I suspect at least one of mine is a little weak as a combo of dirty injectors and old plugs gave me misfires, so if I get a single cylinder misfire at this point I'll get a new coil for that cylinder. If the misfire is a one-off I won't throw away the coil as it will make a fine band aid for a completely failed unit so I'll probably keep with the spare tire.


Sent from my iPhone using Tapatalk Pro

[oldskewel]

On my 2001 3.0i,

shortly after getting it, with extensive, but incomplete (and overcomplete - i.e., stuff on receipts that was not actually done) records, I replaced the plugs.

I found what I believe to be the original plugs from the factory. Said BMW and NGK on them. From how they came out, I can believe it was 170k miles. Done very carefully, no problems, replaced with NGK BKR6EQUP bought at RMEuropean.com. Old ones looked just fine.

No change at all in performance. So I do generally believe that these platinum or iridium or whatever they are plugs last a very long time. But it did seem a little sketchy removing them, so I'd be a little worried about leaving them in there indefinitely.

My coils are all still original and going strong with no problems at all at 189k miles and 18 years. I will not replace any until at least one of them fails, and at that point, we'll see about doing more than one.

[Fifty150hs]

I got to a little over 200,000 miles before I had a coil crap out. Just one cylinder. Swapped it to confirm and the misfire traveled, so I knew that was it. Replaced all 6 because, at that mileage, I figured the rest couldn't be too far behind and I didn't want to deal with one at a time.

[bcredliner]

I agree. Unless the engine is highly modded it is fine to replace coils as they fail. When you do that it is a good idea to put the mileage on the coil. Since coils are so important I never use anything other than OEM coils.

[StephenVA]

+1 to all the responses on your keeping coils until failure....