[topfuel67]

The car has 165k miles. I got it several years ago with 90k miles. All of a sudden it started running rough. I pulled the codes and it showed misfires in cyl 4, 5 and 6. I took it to a bmw shop to diagnose. They said to replace the injectors in 4-6, new plugs and coils and would cost 3300. So I did it myself instead. I noticed injectors 1-3 were previously replaced as they are -12s. Cyl 4 was a -07, cyl 5 was an -08 and cyl 6 -08. I ordered 3 -012s remanufactured off eBay. I ordered new Bosch OEM plugs and coils. I replaced everything and have an autel scanner to set the new injectors. I also replaced the rear O2 sensors as I had a code for one of the downstream injectors.
The car still runs rough. It is throwing a code for cyl 4 and 5 misfire now. I have come across threads saying a walnut blast needs to be done. Would this cause a rough running engine out of nowhere on only 3 cyl? I see that the direct injection caused the valve to get dirty, but don't see how it would be an all of a sudden thing. Any tips from experienced bmw guys is appreciated.

[whyzee125]

As far as I know, you can't really remanufacture these injectors. It would be better if they're simply used than if someone messed with them so I wouldn't necessarily assume that the new injectors are good, but if they are, a walnut blast is a possibility. You seem capable of wrenching so you could pull your intake manifold off and see how dirty the valves are. If it's never been done, or even if it hasn't been done since 90k they are going to be nasty.

Not a whole lot else it could be if your plugs, injectors, coils, and compression are good.

[topfuel67]

Is it common for the gummed up valves to just reach a tipping point where it runs fine one day and then rough and throwing codes the next? I'm sure it's ready for a blasting, but don't want to go through that and it still run rough. I've always doubted remanufactured injectors, but they claimed they were tested and sprayed properly.
I appreciate the reply.

[Shoooter_j]

If injectors may be indeed your issue, don’t bother with these remanufactured injectors, esp. on eBay. I went through the same thing trying to save a few bucks from an ebay seller directly through their online store. Ended up getting used units that may have been good fakes, and both the initial and “replacement” provided misfired when running, then at idle, respectively. Ended up buying once and crying once for a new one from FCP and haven’t had a misfire since.

[iqraceworks]

I would check compression on each cylinder......just to make sure you don't have a piston/ring/valve issue.

[Jklad]

The reman injectors are definately suspect. Nobody can actually do this well unfortunalty. I’d replace those to start to fix the issue and then get a walnut blast anyways cause if you put 65k moles on it and don’t know when it was done previously they are probobly pretty bad, though may not actually be the cause if a code.

[AWD Addict]

Billion threads on this one. Here's one of the longer-running ones.

https://www.e90post.com/forums/showt...stumbling+idle

Injectors, coil packs, fuel pump(s), and intake manifold are all potential and common culprits.

Good luck with the solution.

[topfuel67]

So I have been in denial that the #12 injectors I got were fake, but after seeing so many posts mention that there are I took it to a bmw shop that confirmed the eBay injectors are in fact fake. I even found a site that rebuilds these and they say not to send in ones from eBay as they are fake.
So I bought real ones from Pacific BMW. They looked them up by my vin. However, the real ones are slightly different and don't fit. The fake 12s look like the 7s that I took out. The real 12s have a longer and thicker tip. It also doesn't have a seal. The tip is metal. Is it a cover? I have tried taking it off, but don't want to force it. Does anyone have any experience with these? If they're wrong I don't want to damage the tip by trying to remove it if it is not supposed to.

[topfuel67]

I found a video. It is a cap. I'll install them tomorrow and hopefully it will finally run.

[TiAgAu]

Originally Posted by topfuel67

So I have been in denial that the #12 injectors I got were fake, but after seeing so many posts mention that there are I took it to a bmw shop that confirmed the eBay injectors are in fact fake. I even found a site that rebuilds these and they say not to send in ones from eBay as they are fake.
So I bought real ones from Pacific BMW. They looked them up by my vin. However, the real ones are slightly different and don't fit. The fake 12s look like the 7s that I took out. The real 12s have a longer and thicker tip. It also doesn't have a seal. The tip is metal. Is it a cover? I have tried taking it off, but don't want to force it. Does anyone have any experience with these? If they're wrong I don't want to damage the tip by trying to remove it if it is not supposed to.

https://www.youtube.com/watch?v=aASQ...RleCAxMg%3D%3D

[Jaronbwall]

The injector picture above is the fake? Does the index 12 not use seals anymore? I thought new injectors come with a plastic cap that compresses the seal? Just before installation you pull the plastic, drop them in, and the seal expands.