1/2 of my new OEM Bosch coils were bad

Atx328 · 10-24-2017, 01:11 PM

So I recently had to change out my Valvetronic position sensor which of course necessitated removal of the Valve Cover.

I had already ordered a 6 pack of new OEM Bosch coils before I was able to determine that the sensor was the issue. BTW - thanks for the fine folks on this forum who contributed to helping me get to that correct conclusion. : )

I was planning to return the coils but then I thought - "Why not just put the new ones on and avoid a coil issue a bit further down the road?". Especially since I had to pull them out either way. I replaced the spark plugs about 2-3 months ago.

So when i buttoned everything back up, the car ran so rough it was like a bag of rocks and my cat started to glow red! I shut it down quickly and pull the codes using a Carly adapter/App. Sure enough I had Cylinders 3, 4 & 5 misfires. I checked the connections on the coil leads and the positive seat on a the spark plugs. I ended up putting back the old coils in those cylinders and now it runs like a champ again.

So what is the best alternative Coil to the Bosch? I have lost faith in that product for the immediate and more distant future. Although I suspect that if they work out of the box they will continue to have a normal lifespan.

Or should I just skip it altogether and put the old coils back in all of the cylinders until i have an issue? My 328i is a 2011 with 55K miles, N52 with Auto. I also tend to get fairly poor mileage 20-22 overall with a good amount of highway/freeway driving. I was hoping that the new sensor might help improve that.

El Cheapo Loco · 10-24-2017, 01:48 PM

I've found that the connectors on the Bosch coils are a lot tighter than the OEM ones. Sometimes the connector is not really seated properly even though the clip has been pressed down. 1 out of 6 misfired right after my install and I had to reseat the connector to correct the problem. I've used Delphi coils and they don't have this issue.

Atx328 · 10-24-2017, 02:11 PM

The first thing I checked was if they were seated properly. I pulled them out and put them back in firmly and there was still a misfire.

Then a swapped each of the bad coils position with one that was working and the misfire followed the coil.

Is there a specific Delphi part# that I should look for our just choose one of the site sponsors and order off their page?

10-24-2017, 01:11 PM	#1
Atx328 Private First Class 30 Rep 142 Posts Drives: 2011 328i sport Join Date: Aug 2016 Location: Austin tx iTrader: (0) Garage List 2013 BMW 328i [0.00] 2011 BMW 328 [0.00]	1/2 of my new OEM Bosch coils were bad - best recommendation for an alterative So I recently had to change out my Valvetronic position sensor which of course necessitated removal of the Valve Cover. I had already ordered a 6 pack of new OEM Bosch coils before I was able to determine that the sensor was the issue. BTW - thanks for the fine folks on this forum who contributed to helping me get to that correct conclusion. : ) I was planning to return the coils but then I thought - "Why not just put the new ones on and avoid a coil issue a bit further down the road?". Especially since I had to pull them out either way. I replaced the spark plugs about 2-3 months ago. So when i buttoned everything back up, the car ran so rough it was like a bag of rocks and my cat started to glow red! I shut it down quickly and pull the codes using a Carly adapter/App. Sure enough I had Cylinders 3, 4 & 5 misfires. I checked the connections on the coil leads and the positive seat on a the spark plugs. I ended up putting back the old coils in those cylinders and now it runs like a champ again. So what is the best alternative Coil to the Bosch? I have lost faith in that product for the immediate and more distant future. Although I suspect that if they work out of the box they will continue to have a normal lifespan. Or should I just skip it altogether and put the old coils back in all of the cylinders until i have an issue? My 328i is a 2011 with 55K miles, N52 with Auto. I also tend to get fairly poor mileage 20-22 overall with a good amount of highway/freeway driving. I was hoping that the new sensor might help improve that.
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10-24-2017, 01:48 PM	#2
El Cheapo Loco douchebaggo 186 Rep 972 Posts Drives: stick Join Date: Oct 2009 Location: CA iTrader: (1)	I've found that the connectors on the Bosch coils are a lot tighter than the OEM ones. Sometimes the connector is not really seated properly even though the clip has been pressed down. 1 out of 6 misfired right after my install and I had to reseat the connector to correct the problem. I've used Delphi coils and they don't have this issue.
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10-24-2017, 02:11 PM	#3
Atx328 Private First Class 30 Rep 142 Posts Drives: 2011 328i sport Join Date: Aug 2016 Location: Austin tx iTrader: (0) Garage List 2013 BMW 328i [0.00] 2011 BMW 328 [0.00]	The first thing I checked was if they were seated properly. I pulled them out and put them back in firmly and there was still a misfire. Then a swapped each of the bad coils position with one that was working and the misfire followed the coil. Is there a specific Delphi part# that I should look for our just choose one of the site sponsors and order off their page?
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