[schriss]

Looks like I still have 2 injectors dragging everything down. Another new Index 11 just arrived, it's going in today.

[Dormermike]

I'd replace the entire bank at least

[schriss]

Originally Posted by Dormermike

I'd replace the entire bank at least

I will replace them all eventually. Don't have the money to do it all today.

[schriss]

Number 4 is in. Old one was Index 9, very crusty. It had a marker written "4" on the back which makes me think it was a replacement possibly a used one (knowing the previous owner).
So I have Index 11 in cylinder 4 and 5 now.

[Andystobbs]

You'll get there in the end. Not easy to fund a whole set of index 11 in one go.

[aaronblack]

Wouldn't it be ideal to source all first then swap or at least one bank at a time?

I appreciate it's about a grand worth for 6! But I thought changing only 1 or 2 in a bank would mean the new injectors would have to over compensate hence higher chance to start leaking in future?

[schriss]

Originally Posted by aaronblack

Wouldn't it be ideal to source all first then swap or at least one bank at a time?

I appreciate it's about a grand worth for 6! But I thought changing only 1 or 2 in a bank would mean the new injectors would have to over compensate hence higher chance to start leaking in future?

Yes it would be ideal, but no money for that. I did follow one guy who has been changing his Index 9 into Index 11 one at a time as the 9's failed one every year or so. He had zero issues.

I don't think what you describe can happen. For example when Injector leaks, the other two in same bank are "compensating" by actually opening for shorter period of time. I don't think that has any effect on Injectors, they are just driven by DME and it's all within their reference ranges. If you look at Inpa rough run menu you will see they are always compensating even brand new and 100% functional, their power and opening times are always changing to balance the engine.

That said, I now have replaced two injectors that were confirmed leaking, both in bank 2. That was easy to diagnose.
But I do think something is going on in Bank 1 too and yet there is no leak there. They can be putting less fuel, not opening fully, having bad spray pattern (no mist), so I will have to look at the data and decide which one to replace next as I might have the money for one more (until next month). This has been very helpful: https://bimmerprofs.com/cold-engine-problems-injectors/

[schriss]

I did Lambda probes test in INPA, cool to see expected min/max values for all probes.

[schriss]

Has anyone experienced low voltage on an injector? Injectors 4 and 5 there are marked with ! and have value lower than expected minimum 130V.

[Andystobbs]

The voltage appears to be proportional to the duration for each injector. If they were solenoid I'd be inclined to suggest it's because the shorter duration doesn't allow the coil to saturate, meaning a lower EMF when the field collapses after closing.

As they're piezo though, maybe the stack doesn't get to its fully extended length and such creates a lower voltage when being driven closed.

Thats purely my thoughts backed up by no special knowledge of peizo injectors beyond their basic function and construction.

[schriss]

I see, it's like that one is being opened for shorter time. Looking at bank 2, those 3 on the right side, if we assume they are in firing order then the actual physical order is 5, 6, 4, then 5 and 4 are already replaced but the middle one (showing under 130V) is old Index 9. Interesting observation. I think it will be the next one I will replace.

[schriss]

From here: https://bimmerprofs.com/inpa-upgrade/
"peak voltage while opening the injector.
Readings of energy and voltage can be used to discover damages for piezoelectric elements (micro-flaws, power leakage to injector’s body. The U range in voltage section is not chosen correctly: if the opening time is slightly prolonged (in idle run), all injectors “fall” below minimum voltage of 130V (actual minimum voltage is a bit different number…)"

Anyway, I will be looking at injector adaptations again, the values I see there seem to be relatively large compared to those seen there: https://bimmerprofs.com/injectors-replace-not/
Those are all nice (apart from one) below 0.15mg/stk, mine are all over the place.

But on the bright side I do see Rough Run menu showing much less deviations now after replacing just 2 injectors.

[schriss]

Originally Posted by Andystobbs

The voltage appears to be proportional to the duration for each injector. If they were solenoid I'd be inclined to suggest it's because the shorter duration doesn't allow the coil to saturate, meaning a lower EMF when the field collapses after closing.

As they're piezo though, maybe the stack doesn't get to its fully extended length and such creates a lower voltage when being driven closed.

Thats purely my thoughts backed up by no special knowledge of peizo injectors beyond their basic function and construction.

Guys from Bimmerprofs commented on that: "there are incorrect min/max values selected. 100..140V would be a more corresponding range. So, everything is fine with injectors."
So I assume INPA has incorrect min/max.

I will continue to look at Rough Run menu and injector adaptations to look for the faulty ones.

[schriss]

On cold morning I decided to start the car only for few seconds then shut off and pull plugs 1, 2, 3. This one looks the worst, it's No.2
Spark Plugs 4, 5, 6 are already replaced.
And noticed Spark Plug 3 smelled fuel. Not as much as 4 and 5 which already have Injectors replaced, but I could definitely smell it. So I guess Injector 3 is next up for replacement.
I will probably put new spark plugs in and re-do this test just to be sure it wasn't just bad spark plug.

[schriss]

This happened again: cold start - kind of fine, short drive, car off while shopping, started again after shopping - rpm jumps from 400 to 700 and car a bit shaky, gets better after longer driving. I think this sounds like a typical injector leak, right?

[schriss]

Replaced all bank 1 spark plugs. This is 2 hours after driving. None of those 3 spark plugs smelled fuel. But they were all very sooty, covered in black. I see copper washers are wet from oil and some oil on threads of two of those spark plugs. There is no oil in spark plug holes, but the very bottom does appear a bit wet. As if it was less than a drop smeared over the surface.
I think I might be looking at valve cover gasket replacement.
With this, since I have 1 more new injector, I might just put it into bank 2 to complete bank 2 replacement (4 and 5 are already replaced with new Index 11).

[schriss]

1 hour later I start the car and get the usual rpm jumps on idle. Something is either leaking or not spraying correctly... It goes away after some driving.
Since no fuel smell/leak on spark plugs anymore, this might be tricky to diagnose.
I guess I keep replacing those Injectors until all are new.

Anybody had experienced oil leak into spark plugs and how were the symptoms? Valve cover gasket replacement fixes that?

[Dormermike]

If the top of the head is absolutely spotless and clean of oil I can't see how the cam cover can be leaking oil into the plug wells.

What codes do you have ? Just basic misfire on individual cylinders ? Have you tried moving the coilpacks around to see if that changes anything..


Edit plugs black with soot after two hours of driving is definitely not right. Plugs sooty after a cold start maybe ok. Is your nox ok? My exhaust pipes are sooty since my nox failed sonic presume the plugs are not great either. I must decide what to do about nox as I don't want it fouling up the injectors.

[schriss]

No I meant the sooty plugs were the old ones which came with the car. I was replacing them with new ones, I was smelling them for fuel (none found this time).
The new ones are in now and I did not look at them yet as I barely driven since then.
There is no codes unfortunately. I only had codes and limp mode on two occasions, before I replaced 2 leaking injectors.
My Nox is fixed, replaced with NOXEM and probably thats why all my old plugs were sooty (because nox was broken) and so was the exhaust tips and there was even some unusual smell that is now gone.
Cover Gasket if you look at it has two pieces and there is smaller piece that goes around spark plugs and injectors, so in my case that one might leak a little.

[aaronblack]

Originally Posted by schriss

Replaced all bank 1 spark plugs. This is 2 hours after driving. None of those 3 spark plugs smelled fuel. But they were all very sooty, covered in black. I see copper washers are wet from oil and some oil on threads of two of those spark plugs. There is no oil in spark plug holes, but the very bottom does appear a bit wet. As if it was less than a drop smeared over the surface.
I think I might be looking at valve cover gasket replacement.
With this, since I have 1 more new injector, I might just put it into bank 2 to complete bank 2 replacement (4 and 5 are already replaced with new Index 11).

When I changed all 6 plugs, 2/3 of then were sooty and wet! I couldn't definitely tell if it was oil or fuel but they were wet.

Now all my injectors are old -9 and -3 I believe however I have no rpm jumps or misfires or anything wrong with the car apart from the NOx!

So that makes me think maybe I had oil leaking in as well. But given that the injectors are so old It's a little 'too good' for them not to be leaking.

My rpm starts at 1100 on cold start and gradually goes down to 800/700 and keeps steady

[schriss]

Originally Posted by aaronblack

When I changed all 6 plugs, 2/3 of then were sooty and wet! I couldn't definitely tell if it was oil or fuel but they were wet.

Now all my injectors are old -9 and -3 I believe however I have no rpm jumps or misfires or anything wrong with the car apart from the NOx!

So that makes me think maybe I had oil leaking in as well. But given that the injectors are so old It's a little 'too good' for them not to be leaking.

My rpm starts at 1100 on cold start and gradually goes down to 800/700 and keeps steady

My rpm does the same, but I can feel every now and then some little unevenness, like a jolt, mostly feel it through the seat.
The easily noticeable rpm jumps only happen in one scenario: cold start, all is fine, go drive, shut off, wait 15 mins or more, start up and there will be rpm jumps.
That unevenness I think someone once described it like driving on 5.5 cylinders instead of 6. No codes.
I think plain leaking is just one of many failures. Having a look here: https://bimmerprofs.com/cold-engine-problems-injectors/ tells many different scenarios: incorrect beam from injector, injector doesn't open properly, injector doesn't close in time, etc.
So definitely I will keep replacing my Index 9 with 11 whenever I get money.
I have one new injector here and debating which one to replace Probably will do #6 because it's more difficult AND I will have entire bank 2 replaced.
I will pull my new plugs after few days to see how is the oil thing, if I see oil on threads or them being sooty then I think I will go with gasket replacement, but I will only be inspecting those which are paired with new injectors.

[schriss]

#6 replaced, it looked nasty as all the other ones I replaced. It even has some white residue above the seal.
Now bank 2 is all new Index 11.
Did reset all adaptations and went for a highway drive. Will see how it drives next time on cold start and later on.