[FloridaMan_G82]

they were index 7, did bmw start using decoupling elements later on or...... is this why my injectors are eff'd?

[msjt]

They are required for all injectors. Make sure your head isn't reamed out as a result.

[muncie21]

Pics

[Abax335]

Yeah always required. Sounds like when they pulled them for the recall they didn't install properly. There was a slew of people installing brackets upside down, not installing rings and not installing the Teflon seals ruining the heads and injectors.

If you can put them in and have alot of movement the head might be toast

[FloridaMan_G82]

Originally Posted by Abax335

Yeah always required. Sounds like when they pulled them for the recall they didn't install properly. There was a slew of people installing brackets upside down, not installing rings and not installing the Teflon seals ruining the heads and injectors.

If you can put them in and have alot of movement the head might be toast

god i love bmw techs

[Abax335]

Originally Posted by dlakatos

god i love bmw techs

We're not all bad. Just gotta find one you like and can trust. Only a select few at my dealer I'd trust working on my cars.

I try and train my guys accordingly.


But when you removed the injectors was there soot on them or did you notice which way the bend on the injectors hold down was facing ?

[FloridaMan_G82]

yeah i hear ya on that. 2 injectors had quite a bit of soot, especially cylinder 2, where i was getting the misfire. the clips were on with the apex up like an "n".

i think that is correct to give downward pressure on both injectors?

Originally Posted by Abax335

We're not all bad. Just gotta find one you like and can trust. Only a select few at my dealer I'd trust working on my cars.

I try and train my guys accordingly.


But when you removed the injectors was there soot on them or did you notice which way the bend on the injectors hold down was facing ?

[fmoua916]

Mines didnt have any either they were index 9 i replaced with index 12

[Abax335]

The decoupling elements are primarily for heat not really a gasket. But yes they will be arched up. It sounds like you may still be ok without seeing it

Maybe the excessive heat soak just destroyed them... hard to say

[msjt]

Originally Posted by Abax335

The decoupling elements are primarily for heat not really a gasket. But yes they will be arched up. It sounds like you may still be ok without seeing it

Maybe the excessive heat soak just destroyed them... hard to say

That is not true and it is nearly impossible for them to just disintegrate. They prevent excessive movement from the injector, which usually bores out the holes in the head.

[Jklad]

It's too bad you can't tow the car to the dealership and make them liable for this

[Abax335]

They don't disintegrate, they generally break apart in pieces.

People can put them in and tighten the bracket enough to hold the injectors down but there main purpose or at least what they (BMW) are telling us is thermal related...have had plenty of these come through the shop without rings that didn't do that, just caused injector failure. Both n63 and n54... the holes being out of round is always again in my experience from crossing the hold down bolt and not seating it correctly or having it installed upside down

I was referring to the injectors being destroyed from the lack of decoupling rings from heat soak not the rings themselves.

[FloridaMan_G82]

Originally Posted by Jklad

It's too bad you can't tow the car to the dealership and make them liable for this

I wish my car production date was a few months before the injector recall which is stupid because its the same part

[kaigoss69]

Originally Posted by Abax335

They don't disintegrate, they generally break apart in pieces.

People can put them in and tighten the bracket enough to hold the injectors down but there main purpose or at least what they (BMW) are telling us is thermal related...have had plenty of these come through the shop without rings that didn't do that, just caused injector failure. Both n63 and n54... the holes being out of round is always again in my experience from crossing the hold down bolt and not seating it correctly or having it installed upside down

I was referring to the injectors being destroyed from the lack of decoupling rings from heat soak not the rings themselves.

Having looked at the design of the injection system, my strong belief is that the decoupling element serves two critical functions. The first is to control the insertion depth of the injector into the cylinder head. If the decoupling element is not there, the injector is allowed to be pushed too far into the cylinder head, and the primary seal at the tip of the injector is exposed to combustion gases and fails. This in return is what would causes combustion gases to escape into the cylinder head bore and expose the internal injector mechanism to excessive heat. Second, the decoupling element fixes the axial position of the injector and prevents it from wobbling around under the vibrations of the engine. I believe it is the back and forth motion that the missing decoupling element would allow, that causes the injectors to potentially enlarge the cylinder bores.