DIY How To Fix Ovaled/Loose Injector Bore (No More N54 Misfires!)

suspenceful

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If you own a BMW with an N54 engine, you may have heard of the issue where the injector bores become loose. In this post, I'll explain what that means, why it happens, and how to fix it with the PPI injector bore repair kit.


If you didn't know, the injector bore is the hole in the head of the engine where the fuel injector sits. And if it becomes loose, that means the injector isn’t getting a proper seal to the engine. This can cause a number of problems including misfires, rough idling, and poor performance due to lost compression. And if left unfixed, it will continue to get worse and eventually make your BMW undrivable.

So why does it happen? Well, it's often due to improper injector installation or removal. With these cars being notorious for bad injectors, it’s not uncommon for them to be replaced (albeit improperly). If they were pulled side-to-side while being removed, instead of being pulled up with the proper tool, you can immediately oval out the bore. Fortunately, it can be fixed.

If you catch the damage early like I did, you can fix the bore without replacing the entire head, which can be a very expensive repair upwards of $12,000! The fix I showed in the video above requires a $500 kit from PPI and some patience. It involves rethreading the injector bore and installing a new insert to securely hold the injector in place.

52905625019_7e2f886b16_c.jpg


I show every step you'll need to do in the video above, and in my experience, it worked flawlessly. The bores were actually tighter than they were from the factory, the injectors fit so snug I had to use a bit of force... but no more issues!

52905854465_102ef51b8d_c.jpg


I've tried the teflon tape and copper washer, but neither worked for me long-term. This is the only proper way to fix this issue.
 

SlowE93

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E93
If you own a BMW with an N54 engine, you may have heard of the issue where the injector bores become loose. In this post, I'll explain what that means, why it happens, and how to fix it with the PPI injector bore repair kit.


If you didn't know, the injector bore is the hole in the head of the engine where the fuel injector sits. And if it becomes loose, that means the injector isn’t getting a proper seal to the engine. This can cause a number of problems including misfires, rough idling, and poor performance due to lost compression. And if left unfixed, it will continue to get worse and eventually make your BMW undrivable.

So why does it happen? Well, it's often due to improper injector installation or removal. With these cars being notorious for bad injectors, it’s not uncommon for them to be replaced (albeit improperly). If they were pulled side-to-side while being removed, instead of being pulled up with the proper tool, you can immediately oval out the bore. Fortunately, it can be fixed.

If you catch the damage early like I did, you can fix the bore without replacing the entire head, which can be a very expensive repair upwards of $12,000! The fix I showed in the video above requires a $500 kit from PPI and some patience. It involves rethreading the injector bore and installing a new insert to securely hold the injector in place.

View attachment 81022

I show every step you'll need to do in the video above, and in my experience, it worked flawlessly. The bores were actually tighter than they were from the factory, the injectors fit so snug I had to use a bit of force... but no more issues!

View attachment 81023

I've tried the teflon tape and copper washer, but neither worked for me long-term. This is the only proper way to fix this issue.
You really think the head is that weak ?
That the bore will oval upon removal if injector is "wiggled" out ?
I would think if the head was that weak, it would crack from cylinder pressures we have created from hybrids and singles.
Or spark plugs would have shot out of the head stripping threads for the same reason.
On another note...
Is patent still pending ?
Are we even allowed to talk about this product ?
Those that know....know😉
 

wheela

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Thanks for posting this video! The metal shavings worry me though. I like the idea of using thick grease to catch shavings, but it seems like shavings coated with thick grease would be harder to blow out of the chamber🤷‍♂️?. Did you run a scope down there after blow-out to see if any shavings remained? Not using grease would drop more shavings in, but I wonder if they'd be easier to blow out if not covered with grease?

For those who don't know what slowe93 is talking about, here's the thread:

 

suspenceful

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You really think the head is that weak ?
That the bore will oval upon removal if injector is "wiggled" out ?
I would think if the head was that weak, it would crack from cylinder pressures we have created from hybrids and singles.
Or spark plugs would have shot out of the head stripping threads for the same reason.
On another note...
Is patent still pending ?
Are we even allowed to talk about this product ?
Those that know....know😉

Yes, I do because I've experienced it... and so have others based on what I've seen online. Metal-on-metal force is different than cylinder pressure.

That being said, I don't have any affiliation to this product or brand. I'm simply sharing my experience with it and a step-by-step guide in hopes to help others that may have the same issue.
 
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suspenceful

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Aug 1, 2017
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2015 M3, 2008 135i, 2009 335i
Thanks for posting this video! The metal shavings worry me though. I like the idea of using thick grease to catch shavings, but it seems like shavings coated with thick grease would be harder to blow out of the chamber🤷‍♂️?. Did you run a scope down there after blow-out to see if any shavings remained? Not using grease would drop more shavings in, but I wonder if they'd be easier to blow out if not covered with grease?

For those who don't know what slowe93 is talking about, here's the thread:


Thanks for sharing that other thread, I haven't been on the forums in a while and haven't seen that.

I definitely thought the same things about the metal shavings. It's kind of a double-edged sword to use grease or not. I spent a lot of time blowing shavings out, multiple different times on each cylinder, and am confident that I got everything out. But you could boroscope down in there if you're worried.
 
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suspenceful

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@suspenceful curious how you managed to get your kit? From the looks of it many have had issues where they paid and received nothing.
I emailed them before buying to make sure they were available, got a response, ordered, went a few days without hearing anything, followed up, then got my kit a few days later.
 
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SlowE93

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Yes, I do because I've experienced it... and so have others based on what I've seen online. Metal-on-metal force is different than cylinder pressure.

That being said, I don't have any affiliation to this product or brand. I'm simply sharing my experience with it and a step-by-step guide in hopes to help others that may have the same issue.
I understand what you are saying, but I would think to oval it out , it would have to be quite a bit of force, along with a substantial angle at that,to cause damage.
Most failures I have read about ......nevermind I'll get banned for no reason again 🙄
 
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