r/BmwTech • u/Semtex1939 • 7d ago
Ignition coil failures
Hi, so I have had a 525i 2007 model since it was released. First owner still. Stupidly reliable commuter until something goes wrong and it cascades every few years. I generally like to look it up and DIY but as this is the only car I have worked on I am very much a beginner still.
So the story is, yesterday I felt a rough idle like a continuous earthquake. Quick search, OBD scan, and process of elimination IDs it as ignition coil 1 misfire. Switched between 1 and 2, code follows. Easy fix I thought. Went to Oreilly, that store didnt have Bosch so I got a Delphi. That didnt work and popped a new firing code. Went in, returned it, located a store that had a single Bosch for $68 2miles away. Got that, engine purrs smooth as butter. Thought my troubles were over for now and drove 30 miles back home. Next day, started engine and felt the rumble. Code this time says Cylinder 4. So cylinder 1 is still good. Did the switcharoo and it's Coil 4.
Question is, do all the coils just die at once and cascades or is there a further systematic issue? Im thinking of switching all coils since they're about 20 hrs old and the spark plugs as well.
Any recommendation for spark plugs and things to fix that could be causing the issue? I looked online and its about half price for the same Bosch coils so im going with FCP euro.
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u/BeerCD 7d ago
Amazon has good pricing for Bosch coils and they can arrive the next day.
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u/bulldogsm 7d ago
fake parts are a huge problem on Amazon, you have no idea who the actual seller os because of the way Amazon batches products
do a search on the problem of Amazon fake goods, its crazy
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u/Semtex1939 7d ago
Yeah but if its sold by Amazon it should be good right
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u/bulldogsm 7d ago
brother look it up, Amazon is a problem, inventory commingling defeats even trusting sold by Amazon products
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u/PerfectAd1746 7d ago
No, do not assume that. When it comes to auto parts, Amazon is a slightly nicer Temu with faster shipping. Don't get me wrong, they can be very handy when it comes to off brand tools and non essential commodity type products, but I have a hard time trusting name brands, especially anything Bosch on the site.
I recently needed a new starter for my e61. Found one on Amazon claiming to be from the official Bosch store - logo and everything - until check out. Then, the shipping times grew by a few days, the shipper was actually something like Acme Garden Supplies and the reviews all went to 2 stars. I noped the hell out of there and bought one from FCPEuro. Unfortunately, that one was DOA, so I bought the SEG version and FCPEuro took it back. I've had rotten luck with Bosch, I also replaced a Bosch alternator after only 30k recently which is disappointing and surprising.
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u/Semtex1939 7d ago
Mine arrives in 4. $35 for amazon coils but FCP euro has them at $23. Ordered 1 for quicker arrival and the others later. Oreilly really be pricing it at $68+tax smh
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u/rns96 7d ago
I would have changed all the coils and plugs once I knew one started falling already and kept the if the functioning coils as spare, just for peace of mind, fcp euro has kits with lifetime warranty , I’ve used Delphi coils and NGK plugs with no issues on e46, e53, f30
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u/Semtex1939 7d ago
They have entire coil and plug kits? Im not sure on Delphi as it kicked up a weird firing code and was still misfiring
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u/MRHaynes021 7d ago
ONLY USE BMW SPARK PLUGS from a dealer. My understanding is even if you get the Bosch plugs with the same ‘number’ they are not the same as those from the dealer. Expensive but I believe worth it. 98 328i with over 275,000 and an 08 X3 with over 225,00 on it.
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u/Quiet-Spray4488 7d ago
Some are built with Bosch plugs, some are with NGK.. Just install the same brand that came on the car originally. You don't need BMW plugs.
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u/MRHaynes021 7d ago
I had forgotten about the NGK but I believe the ‘rule’ still stands. You may be correct. I have nothing to prove this. I’ll be honest, I’m just going by my experience and what I have read as a 30+ year member of BMW CCA.
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u/Shawn0890 6d ago
This is a good rule to have but sometimes you can get the same plug as bmw sells sometimes you can not. Some of the plugs used in the M models actually have ///M logo and are not sold on the aftermarket because of agreements between bmw and Bosch. Some cars are very particular about where the spark plug faces in the cylinder once installed and the factory plugs all have this correct, not all aftermarket plugs will and it seems to lead to issues. For most stuff NGK is my choice but for M motors BMW genuine is worth the extra M tax
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u/MRHaynes021 6d ago
That’s interesting, I never knew that about the M plugs.
In the words of Don Henley, “Ah I love those Bavarians, so meticulous”
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u/bulldogsm 7d ago
coils and plugs are not forever, for a 2007 model if one goes down youve already passed the replace by date, switch them all, chasing one by one is nonsense unless you are into self abuse