E30 M42 Fuel Rail/Injector Removal

[roguetoaster]

When I first got my car the valves were clean, but the manifold was very cruddy. Now, between driving it hard and synthetic oil (not sure if this part matters) the intake tract stays fairly clean, although there is some oil film.

[othatseric]

When you guys had the manifold off how much crud build up was there inside it and on the backs of the valves. Planning this job over the winter, car has 130k miles.

When i did mine at 280k km, back of the valves were OK clean, both intake manifolds were pretty gunked up. But it kinda varies depending how well its been maintained in the past.

[unixnerd]

When you guys had the manifold off how much crud build up was there inside it and on the backs of the valves. Planning this job over the winter, car has 130k miles.

[MouseRat]

Definitely easier to get the injectors off when the lower manifold is off the car. Mine took some careful encouragement with a screw driver, but after replacing the o-rings, reassembly was a breeze!

Yeah, same here. I used a small pry bar between the fuel rail mounting tab and the fuel rail mounting surface on the intake manifold. At first, I wasn't even sure they were going to separate. I let some penetrating oil soak in for a bit and eventually the injectors came out of the intake manifold.

They were a right pain! They took some persuasion from a big big screwdriver. The lower o-rings were really hard and nearly cracked.


I haven't actually put it back together yet because I'm still waiting for my injectors to get shipped back from their service.
Reassembling outside the car definitely looks way easier.
Thanks for the tips lads

[mike.bmw]

Definitely easier to get the injectors off when the lower manifold is off the car. Mine took some careful encouragement with a screw driver, but after replacing the o-rings, reassembly was a breeze!

Yeah, same here. I used a small pry bar between the fuel rail mounting tab and the fuel rail mounting surface on the intake manifold. At first, I wasn't even sure they were going to separate. I let some penetrating oil soak in for a bit and eventually the injectors came out of the intake manifold.

[hamann318is]

Definitely easier to get the injectors off when the lower manifold is off the car. Mine took some careful encouragement with a screw driver, but after replacing the o-rings, reassembly was a breeze!

[mike.bmw]

Looks like you already got this sorted, but when I recently replaced my "mess under the intake", I just pulled the entire lower intake manifold assembly (rails, injectors, hard fuel lines, wiring harness, etc) and then separated/reassembled it on the work bench. Much easier to deal with that assembly off the car.

Here it is with new injectors, fuel hoses, and clamps:

[MouseRat]

Might want to attempt the "under intake mess removal" while you're in there! That is, if it won't make you fail your MOT!

I Passed my MOT a week ago ;D

All that stuff is coming out! The previous owner has basically done it for me.

He did all the new vacuum lines and coolant lines, he just couldn't be bothered to take the manifolds off to get the unused clump of rubber out

I don't think removing this should effect anything in the eyes of the law...I'll find out when my next MOT is due!

[varg]

Might want to attempt the "under intake mess removal" while you're in there! That is, if it won't make you fail your MOT!

[MouseRat]

All Sorted. Thanks Gents :up::up:



(I plugged the intake ports right after this)

[MouseRat]

Like I said in the previous post, just pull the plastic wiring holder off the injectors. With a light to moderate amount of force it should just pop off all 4 injectors.

That will give you plenty of room to pry up against the valve cover without prying against the plastic wiring holder.

Oh I see what you mean now, the plastic wiring holder separates BEFORE you pull the rail & injector assembly out.

Thanks for the help man. Really appreciate it.

[Balleristic31]

Ahh this seems to be my problem.

So then the plastic wiring holder just comes up with the rail, and I take the injectors out the rail?

Like I said in the previous post, just pull the plastic wiring holder off the injectors. With a light to moderate amount of force it should just pop off all 4 injectors.

That will give you plenty of room to pry up against the valve cover without prying against the plastic wiring holder.

[MouseRat]

The injectors often are stuck in the lower manifold and usually need some careful convincing (prying) with a tool against the valve cover to pop up and out.

Ahh this seems to be my problem.

So then the plastic wiring holder just comes up with the rail, and I take the injectors out the rail?

[Balleristic31]

Remove both fuel feed and return lines. Then just snap the wiring cover off the injectors (no need to pull those tiny metal clips on them they are ment to just break away). Then pull the two 10mm nuts attaching the rail to the lower manifold.

The injectors often are stuck in the lower manifold and usually need some careful convincing (prying) with a tool against the valve cover to pop up and out.

[MouseRat]

I've managed to take the throttle body off the intake and the upper manifold off the lower manifold.

I basically can't seem to pull the injectors out the head. I think I can just leave all the wiring attached, pull out the injectors and undo the wiring clips on the underside after?

The guide I found says 'carefully' pull them out (doesn't elaborate), but there's nothing careful about the amount of force needed

Pic of where I'm at: