[F31B48]

Originally Posted by rkwdev

Hey, my N53 sometimes provides me with codes of misfiring on 5/6 cylinder and uneven run of 3rd cylinder. Is it possible that 3rd injector is bad and 1 one too instead of injectors in cylinders 5/6?

Yes definitely possible. It is a known issue with n43/53 misfire detection. Bimmerprofs.com have some very detailed analysis of the issues with these engines.
https://bimmerprofs.com/misfire-counters/
https://bimmerprofs.com/

[rkwdev]

Thanks, I'll be updating.
My car is going to bmw workshop so I hope for some good dignostic. For now it just have rough run in the morning, the codes from misfiring poped up once.
Financially im prepared but the shortage of injectors is a nightmare for me, like what if I can't get all six.

[Phil325i]

Originally Posted by rkwdev

Financially im prepared but the shortage of injectors is a nightmare for me, like what if I can't get all six.

If you can't get N53 injectors, fit six N54 injectors (index 12, part number 13538616079). Provided they are coded in and all adaptations cleared, they will run just fine.

[rkwdev]

Okay, so the guys from the workshop findout that on cold start injector in cylinder 2 and 6 leaks. Do you think is it possible to replace three injectors (index 11) in bank one to not mix them and in another bank change the one that leaks with leftovers from the replaced bank ( I assume that in both banks injectors were not changed since the car went out from factory) ?
Or should I stick to the full set for N54 injectors?
One N53 injector is like 377 pounds, while the N54 323 pounds.

[martinfc]

Originally Posted by rkwdev

Okay, so the guys from the workshop findout that on cold start injector in cylinder 2 and 6 leaks. Do you think is it possible to replace three injectors (index 11) in bank one to not mix them and in another bank change the one that leaks with leftovers from the replaced bank ( I assume that in both banks injectors were not changed since the car went out from factory) ?
Or should I stick to the full set for N54 injectors?
One N53 injector is like 377 pounds, while the N54 323 pounds.

You only need to change the bad injectors, the theory that you have to match the same index numbers per bank appears not to be true. see:

https://bimmerprofs.com/compatibility-of-injectors/

I followed this advice following getting my N53 diagnosed by Bimmerprofs last year, I have a mix of Index 9 and Index 11 in both banks and it runs perfectly.

More important is to ensure the diagnosis is correct. Personally I would only trust Kaspars at Bimmerprofs to diagnose N43/N53 engines, using INPA live data. If you really only have two bad injectors, then that's all you need to replace.

I hope it goes well for you.

[Tical]

Hi Guys,

I just registered here and I am not sure how to create a post.

I bought a 325xi with the N53 and have been trying to fix it for the last 2 months or so.

The issue I am facing is a cold start rough idle and combustion misfires in cylinder 4(this is the current issue. It had others prior to this one)

What I have replaced so far in order:

- 6 new OE spark plugs
- 3 new injectors 11 (cylinder 1, 2 and 4). All Injectors were Index 11. Only the one in Cylinder 2 was index 2.
- 2 new Vanos Solenoids
- new NOX OE and all 4 Lambda Probes/ O2 sensors with brand new Bosch ones
- 6 new Bosch coils

The car runs much better now, but when I start it early in the morning it is fine for like 30 seconds and then the RPM needle starts to bounce between 550 and 700 and the car shakes. After that the engine light comes on and it is always cylinder 4, where the injector, coil and plug were replaced. Sometimes if I start it for the first time in the afternoon in a warmer weather, it doesn't misfire and I feel just a slight rough idle. If i drive it for 30+ minutes though, I get a cylinder 4 misfire again. I saw in the BMW history that all 6 injectors(index 11), the HPFP and the NOX were replaced at 88k KM. They scanned my key and said the car is at 233k at the moment.

Any advice will be of great help. Both me and my mechanic are not sure what to do now...

Thank you in advance!

[Phil325i]

I assume you've had the DME read for fault codes? At your mileage I would definitely clean/replace your VANOS filters/non-return valves (part number 11367541692). Also worth cleaning the MAF sensor and throttle butterfly. Otherwise you seem to have done all the right things...other than replace all the injectors.

[Tical]

Hey Phil,

Thank you for the swift reply!

I am not sure about the DME... Could you share some more details? Do you suggest it might be a software issue?

It's my first time hearing of Vanos filters so I will definitely have that checked. We have cleaned the MAF and throttle.

The thing I don't get is how is it always cylinder 4... We first replaced the spark plug, then the injector and finally the coil in that cylinder, but yet it keeps misfiring. Could it be due to old injectors in 5 and 6, although they are index 11? They do have 150k km on them, which is quite a lot. Could it be number 4 compensating for both of them, and thus, causing the misfires and rough cold starts always in cylinder 4?

The next step I was considering is replacing the other 3 injectors and/ or the valve cover.

[Tical]

Originally Posted by Phil325i

I assume you've had the DME read for fault codes? At your mileage I would definitely clean/replace your VANOS filters/non-return valves (part number 11367541692). Also worth cleaning the MAF sensor and throttle butterfly. Otherwise you seem to have done all the right things...other than replace all the injectors.

Hey Phil,

I am not sure about the DME... Could you share some more details? Do you suggest it might be a software issue?

It's my first time hearing of Vanos filters so I will definitely have that checked.

We have cleaned the MAF and throttle.

The thing I don't get is how is it always cylinder 4... We first replaced the spark plug, then the injector and finally the coil in that cylinder, but yet it keeps misfiring. Could it be due to old injectors in 5 and 6, although hey are index 11. I guess they do have 150k on them, which is quite a lot. Could it be number 4 compensating for both of them, and thus, causing the misfires and rough cold starts always in cylinder 4?

The next step I was considering is replacing the other 3 injectors and/ or the valve cover.

[Tical]

Recorded this morning - This is what is usually looks like. If I start it for the first time in warmer weather, it's a bit better.

[Phil325i]

Even when stable your idle is low. It should be about 750rpm. Yes, if it were me, I would replace all the injectors, especially after that high mileage. My index 11s lasted about 60K miles. By reading the DME I meant using a diagnostic programme to read any fault codes. See if you can find an indy who has the BMW diagnostic software that can test the engine while running.

[Tical]

Originally Posted by Phil325i

Even when stable your idle is low. It should be about 750rpm. Yes, if it were me, I would replace all the injectors, especially after that high mileage. My index 11s lasted about 60K miles. By reading the DME I meant using a diagnostic programme to read any fault codes. See if you can find an indy who has the BMW diagnostic software that can test the engine while running.

Oh, my bad. Yeah, my indy does check them with his scan tool. It is not INPA, however. He got INPA once to test injectors and he said that all of them have spray rates close to 0, which indicates they work well. He usually uses some software that is suitable for other brands as well. Unfortunately I live in a small town so this is the only troubleshooting I can get. Every morning when I start it idles like this and logs "Cylinder 4 combustion misfire" when he checks it. We discussed the possibility today of replacing the other 3 injectors. We pulled out the spark plug in cylinder 4 and it wasn't dirty. We couldn't find any oil leaks from the valve cover, nor are there fault codes related to that like air supply to both banks. Yesterday, however, for like 2-3 minutes I was hearing a whistling noise from the engine (not 100% sure). It stopped when I got a chance to stop and open the hood. I didn't hear it after that or today. So I guess the next and probably final step before I take it to BMW is to replace the other 3 injectors. We really don't know what else could be causing the issue. He said he had checked for vacuum leaks and found none. We replaced all O2 sensors just to be sure it's not from them. I bought the car for 6k Euros and after purchasing the 3 new injectors it will be close to another 6k for repairs alone, which is quite frustrating. I just hope this finally fixes the issue because it has been 2 months of frustration and disappointments...
PS: Thank you for the swift reply again!

[Phil325i]

I feel your pain! Having just replaced my injectors (again) and HPFP, I know about big bills!

Just be aware the valve cover can develop hairline cracks due to heat cycles. Also, a whistling noise might indicate problems with the PCV system. My indy advises if you're removing the valve cover for leaking gasket then replace the whole cover as a precaution.

If you try to remove the oil filler cap with the engine running, do you experience excessive vacuum resistance?

[Tical]

Originally Posted by Phil325i

I feel your pain! Having just replaced my injectors (again) and HPFP, I know about big bills!

Just be aware the valve cover can develop hairline cracks due to heat cycles. Also, a whistling noise might indicate problems with the PCV system. My indy advises if you're removing the valve cover for leaking gasket then replace the whole cover as a precaution.

If you try to remove the oil filler cap with the engine running, do you experience excessive vacuum resistance?

My indy tested it 2 weeks ago and said he felt a strong suction. I think the cover has never been replaced. I guess it is possible that a crack near cylinder 4 might also be a cause of the misfires? We haven't noticed oil leaks anywhere though. Oh the thing I forgot to mention is all 6 injectors were replaced at 80k, but I bought the car with a Index 2 injector in cylinder 2, which is a bit shady. I took it to BMW for an initial diagnosis and they said there were issues in cylinder 2 and 4. We have replaced that one and haven't heard from cylinder 2 since.

[Phil325i]

Originally Posted by Tical

My indy tested it 2 weeks ago and said he felt a strong suction. I think the cover has never been replaced.

There shouldn't be strong suction, just a light resistance. Maybe your PCV system is shot (it's combined in the valve cover on the 330i I believe, so replacing the cover would sort that issue...

[Tical]

That's the membrane inside the cap that can't be unscrewed, but has to be cut off instead, right?
I've seen a lot of people in german forums complaining about that.

[0l0dom0l0]

If you have a whistling CCV then I'd reccomend replacing the valve cover before you go any further. Given how fussy the cars are it is probably best to spend the extra and get the genuine BMW cover too. A faulty CCV causes havoc.

Before you go any further sort the CCV issue and ensure you have no NOX faults present. Once that is done I'd reccomend clearing all adaptions and following the re learning process on bimmerprofs.

If you still have issues after that you could look at walnut blasting (which I reccomend) as the N53 uses EGR and the inner 2 cylinders especially seem to suffer with carbon build up on the inlet valves as the EGR joins the inlet between cylinders 3 and 4.

I can't quite understand which injectors you have where and which ones you've replaced but if you have been removing them to test make sure you fit new seals and decouplers. It may also be worth checking that the codes on your injectors match what is stored in the DME - or simply re doing this step all together and move all the injectors around and re coding.

[Tical]

Originally Posted by 0l0dom0l0

If you have a whistling CCV then I'd reccomend replacing the valve cover before you go any further. Given how fussy the cars are it is probably best to spend the extra and get the genuine BMW cover too. A faulty CCV causes havoc.

Before you go any further sort the CCV issue and ensure you have no NOX faults present. Once that is done I'd reccomend clearing all adaptions and following the re learning process on bimmerprofs.

If you still have issues after that you could look at walnut blasting (which I reccomend) as the N53 uses EGR and the inner 2 cylinders especially seem to suffer with carbon build up on the inlet valves as the EGR joins the inlet between cylinders 3 and 4.

I can't quite understand which injectors you have where and which ones you've replaced but if you have been removing them to test make sure you fit new seals and decouplers. It may also be worth checking that the codes on your injectors match what is stored in the DME - or simply re doing this step all together and move all the injectors around and re coding.

I think the whistling I heard was the injectors + my mind playing tricks on me .

I am currently driving without the decorative bmw plastic cover so the injectors are more noisy. I replaced the NOX with a brand new one and there are no NOX errors anymore.

I have heard of he possibility that the cylinder head and valves might get carbon build up, hence causing that cylinder to misfire. I have no idea what should be done in that scenario though. Does walnut blasting and carbon clean resolve the issue or is it something else?

[Dormermike]

I'd swap injector, plug and coil from cylinder 4 and cylinder 1 and see if fault moves. If still cylinder 4 playing up perhaps walnut blast or mosfet playing up rare but can happen.

Ccv easy test check bimmerprofs website.

[Tical]

Hi gents,

So quick update from this morning:

We checked the scan tool and although the RPM needle showed 550, it was actually 650 in the tool.

We also checked the injector spray rates and cylinder 4 and 6 logged differences up to +1.3 from time to time. I guess it's possible that my indy put the 3 new injectors in other cylinders when doing tests. We hadn't replaced coils during these tests. I will purchase a new injector and start swapping around 4 and 6.

Thank you all for your replies and tips!

[rkwdev]

Originally Posted by Tical

Hi gents,

So quick update from this morning:

We checked the scan tool and although the RPM needle showed 550, it was actually 650 in the tool.

We also checked the injector spray rates and cylinder 4 and 6 logged differences up to +1.3 from time to time. I guess it's possible that my indy put the 3 new injectors in other cylinders when doing tests. We hadn't replaced coils during these tests. I will purchase a new injector and start swapping around 4 and 6.

Thank you all for your replies and tips!

Hey man,
the best way to check if it is caused by coil, injector or spark plug is to exchange between cylinders in the same bank. So if you have misfire in 4th cylinder then exchange 4th cylinder spark plug with 5 cylinder spark plug, next exchange 4th cylinder coil with 6 cylinder coil. In the morning checks logs again, if it misfire in 5 its spark plug, if 6 then its coil, if 4 then injector could be bad.

[Tical]

Hey guys, so we replaced the 3 other injectors on Friday.
The thing is we took all 6 out and we weren't 100% sure which were the old 3 injectors and which were the 3 we had already replaced. They were all dirty at the bottom and had carbon buildup... Is this normal for the new ones to look like this?. We checked the year that they were manufactured and we replaced 2 old ones for sure. We were not sure about the third one but I think we got it right.

So I started the car the next day at noon and the idle looked like this. I felt a rough idle only for like a second.

https://youtu.be/4l9y7altn6w

While I was driving I got a check engine light but I think it is for the cat again as a cylinder did not shutdown like it would in case of a misfire. I will check the code on Monday with my indy. Any tips if it is indeed a cat error? Also does the idle look fine to you now? I think it might be fixed but I don't want to jinx it

Thank you in advance!