injectors leak after rebuild - M5

[4heid]

I have just finished rebuilding the intake manifold, throttle bodies, injectors and completed the valve job.
While attempting to restart for the first time, which didnt happen, the injectors started leaking. I performed 4 short 5 second starting sequences with a few pumps of the pedal to get fuel into the fuel rail and injectors again. It didnt get close to starting on any of the attempts and on the 4th, 3 of the injectors started to leak down from the fuel rail O ring area.
The injectors were just rebuilt so the O rings are new. I have seen this happen before but dont know if its due to too much pressure now built up in the rail from a few start attempts or its part of the non-start issue.

I can say that they did seem looser going back in the rail than getting them out, which took some muscle.

Any thoughts?

[demetk]

Maybe you tore some o-rings when you inserted the injectors? Did you lube them up with engine oil before installing?

[4heid]

i put a tiny amount lube and honestly they felt too lose to me but they were done by MEPEH who does only BMW injectors. It surprises me the rings wouldnt be right.
It took tremendous force to get them out but they went in like butter.

[5mall5nail5]

Double check the o-rings are the right ones. I know there are a few that "fit" but are not correct. They should require some force to get (not a lot, but some) even if lubricated. What lube did you use? Try to only use motor oil as some lubricants can swell or shrink the rubber. Might be best to order new OE o-rings just to be sure.

[4heid]

i think i have to go that route, ordering new factory rings just in case.
They seemed lose going in.
I used dielectric grease, with only a light covering on my finger that didnt add anything you could see, just shined the surface of the ring.

[4heid]

update...it was 1 the ring which didnt allow the rest to seat and slightly obscured the rail.
one of them had flat-sided and was the one causing the issue.


an odd issue. it wasnt torn but most likely was a qc problem on the ring as it looked like it formed that way.

[Waitedog]

you should put the injectors in the fuel rail before trying to seat the injectors in the engine that way you know if you have them all seated in all the way.