[CheesecakeInjection]

Inspected all my injectors, a few had leaky seals and one had a busted tab. It's weld just popped off. See pic:

Whats this tab do? Do i

A weld it back?
B Ignore it, its useless
C Actually need a new one?

My engine has rod knock or piston slap. Could this busted tab or shot seals cause piston slap?

Side note, do you lose any noticeable compression with leaky injectors like this? Curious if this guy will be faster when my new seals are in.

[Cloverdale]

It's a centering tab that's broken off, but I think you'll be relatively centered without it, particularly if you attach fuel line before tightening hold down bracket. The burn / black markings on the injector bottom could well be the result of an oil leak and not necessarily leaking seals. A valve cover leak into my cylinder 5 fouled my injector. These injector seals don't seem to be quite as delicate as many describe as I've non problematically replaced injectors with used without replacing seal or coupling ring.

[CheesecakeInjection]

Originally Posted by Cloverdale

It's a centering tab that's broken off, but I think you'll be relatively centered without it, particularly if you attach fuel line before tightening hold down bracket. The burn / black markings on the injector bottom could well be the result of an oil leak and not necessarily leaking seals. A valve cover leak into my cylinder 5 fouled my injector. These injector seals don't seem to be quite as delicate as many describe as I've non problematically replaced injectors with used without replacing seal or coupling ring.

Originally Posted by Cloverdale

It's a centering tab that's broken off, but I think you'll be relatively centered without it, particularly if you attach fuel line before tightening hold down bracket. The burn / black markings on the injector bottom could well be the result of an oil leak and not necessarily leaking seals. A valve cover leak into my cylinder 5 fouled my injector. These injector seals don't seem to be quite as delicate as many describe as I've non problematically replaced injectors with used without replacing seal or coupling ring.

That bracket that holds the injector in place, does it hold it in by pushing down on the decoupler?

Some people on facebook seem to think this tab holds it down, but i think you sound correct

[CarAbuser]

I'm pretty confident those tabs are required to properly locate the injectors. The bent ones will also fall off as soon as you install them.

I don't know how well they can be welded back but I wouldn't run without them, you risk having a loose injector that can damage the head.

[Cloverdale]

Originally Posted by CheesecakeInjection

That bracket that holds the injector in place, does it hold it in by pushing down on the decoupler?

Some people on facebook seem to think this tab holds it down, but i think you sound correct

The hold down bracket sits on top of / wraps around the front of the non removable injector bracket located above the injector tab (above the tab you broke). The removable decoupler fastens below the tab and sits inside the hole in the head. With all of the fixed, firm contact points the injector can't help but be centered even without the broken tab.

[semper]

Hello, I have a same problem. Does it really work without the tab and tab is only centering piece?

[iqraceworks]

The tab is there just to locate the injector radially....to keep it from rotating. But if you have a metal fuel line hooked to the injector, it can't move anyways. It has nothing to do with holding the injector down, or clamping it in.

I wouldn't worry about it. I would be more worried about the oil on the bottom of that other injector in your pictures. Maybe your valve cover gasket is leaking?

Also...install all new seals before you put those injectors back in the head.

[SlowE92]

Originally Posted by CheesecakeInjection

Inspected all my injectors, a few had leaky seals and one had a busted tab. It's weld just popped off. See pic:

Whats this tab do? Do i

A weld it back?
B Ignore it, its useless
C Actually need a new one?

My engine has rod knock or piston slap. Could this busted tab or shot seals cause piston slap?

Side note, do you lose any noticeable compression with leaky injectors like this? Curious if this guy will be faster when my new seals are in.

Long story short. I had a misfire and what sounded like rod knock on my 535xi. Thought that my engine was toast, started pulling everything off and noticed that the hold down bracket on one of the injectors was slightly loose and the O-ring was burnt off and the decoupler was toast and basically the injector was bouncing up and down making it sound like rod knock. Don't know if this is the case for you. If it's a loose injector then it can sound like rod knock but it will usually follow up with a misfire code. If the car had that for a while the issue would be the injector basically boring out the hole and making it bigger.