[VinnyBay]

Hello Everyone,

Hope you all are doing well, I'm currently experiencing some engine misfires/stuttering from my n52. I was wondering if you all might have an idea on what is causing these stutters?
i apologize ahead of time just in case this is an easy google search away (i'm new here soo )

When the car is first started up and in park, idle doesn't seem like a problem, but when rpms settle, idle starts to jump a bit, and you can feel the engine shake. It's further worsen if AC is on, no matter how high or low, the shakes get more frequent and more harsh. When in drive, it stutters as well as in neutral.

Ive been monitoring the short term fuel percentages and bank 2 has a significantly higher negative (-8%) value compared to bank 1 (-3%). When rev-ed up to 3K rpm, Bank 2 short term percentages are still in the negatives (-6%). Where as Bank 1 percentages are positive (3%)
The car running lean is also further confirmed my the car sounding like a diesel engine from the back half of the engine (bank 2).

I'm going to get a bunch of flack for it but, using a generic code scanner (veepeak obd2, and app: "car scanner", since Bimmercode said my 06 325xi was too old) a common code coming up for me is the P114D code. which is either O2 sensor going bad or N52 Running lean

Excuse the failing blower motor, Im getting around to fix it!!

Park / neutral usually has more fluctuations

So far i've cleaned out the Vanos solenoids, I've ran through a bottle of techion (stutters less prominent) , replaced all spark plugs with OEMs, clean up maf sensor, and gotten a oil change and filter from the dealership.
I've inspected all the coils and i don't think they are the problem, But cylinder 2 has a tear in its insulation and is a different brand than the rest. but it's working, and doesn't seem likes it's failing.

Thanks y'all for taking time out to read these paragraphs and offer feedback! i just didn't know where else to turn and i ran out of hope trying to fix it. As much as this thing stutters and squeaks at me, i'll still love my n52, Stay safe out there y'all!

[b1aze]

Have you checked the plug for the eccentric shaft sensor for oil?

[W37V]

Originally Posted by VinnyBay

Your car has 200k miles and is almost 16 years old... so few things could be wrong...

Have you checked for vacuum leaks? What you are describing might be tied with vacuum leaks. Have you done any repairs lately? Hoses become brittle and crack.

Also, how's your maf? is this behavior same with maf disconnected? Disconnect the maf and see how it is behaving.

What brand of plugs did you use? Tbh, I don't think coils have anything to do with this, but replace them anyways. At 200k miles, they are most likely to fail.

[VinnyBay]

Originally Posted by b1aze

Have you checked the plug for the eccentric shaft sensor for oil?

Nope, but i'll definitely look into it, i'd assume if there's oil in it, that's not a good thing

[VinnyBay]

Originally Posted by W37V

Your car has 200k miles and is almost 16 years old... so few things could be wrong...

Have you checked for vacuum leaks? What you are describing might be tied with vacuum leaks. Have you done any repairs lately? Hoses become brittle and crack.

Also, how's your maf? is this behavior same with maf disconnected? Disconnect the maf and see how it is behaving.

What brand of plugs did you use? Tbh, I don't think coils have anything to do with this, but replace them anyways. At 200k miles, they are most likely to fail.

Nada, Although watched some youtube videos on the subject, and i might take a look near the maf and surrounding hoses. I suspect it has to do with the hose between the maf and the throttle body, Heard it can crack easily.

So far i haven't dug too far into the car, only what's on the surface, i just didn't know where to start. I hope it's nothing too big, like my starter because that's definitely going out.
Broke college student and old bimmers don't mix that well, maybe i should just got a civic

Also i used the NGK Laser plugs, if i recall

[E92William]

The driving experience between my old civic and my e92 are light years apart even though the civic was great. So I think you made the right choice.

You most likely have some kind of small vacuum leak which is why you're getting that code too. What scanner do you have? If you got an obd2 Bluetooth one you might be able to use "bmw deep obd" app to get bmw specific codes to help pin point this better. Or use a laptop and get bmw tools from bimmergeeks for free and scan with inpa with the bimmergeeks kdcan cable.

Do a look around for leaks though I think if you said it got a bit better with Techron you could swap the bank 2 injectors to bank 1 and see what happens. Injectors rarely fail on these engines but yours is also high mileage. Other thing that comes to mind is an intake gasket leak which again at that mileage could need attention or a pcv hose cracked. Get yourself a little smoke machine for parties to put smoke in the intake with the engine off.

[W37V]

Originally Posted by VinnyBay

Nope, but i'll definitely look into it, i'd assume if there's oil in it, that's not a good thing

no its not. it cases bunch of issues (low power, unable to rev to redline, poor fuel economy, etc) BUT, it's not that difficult to fix as diy. maybe 3 hours start to finish.

[VinnyBay]

Originally Posted by E92William

You most likely have some kind of small vacuum leak which is why you're getting that code too. What scanner do you have? If you got an obd2 Bluetooth one you might be able to use "bmw deep obd" app to get bmw specific codes to help pin point this better. Or use a laptop and get bmw tools from bimmergeeks for free and scan with inpa with the bimmergeeks kdcan cable.

Hmmmm interesting, might have to look into that, thanks a bunch! I assume there aren't many apps like "bmw deep obd" for apple devices huh?

Originally Posted by E92William

Do a look around for leaks though I think if you said it got a bit better with Techron you could swap the bank 2 injectors to bank 1 and see what happens. Injectors rarely fail on these engines but yours is also high mileage. Other thing that comes to mind is an intake gasket leak which again at that mileage could need attention or a pcv hose cracked. Get yourself a little smoke machine for parties to put smoke in the intake with the engine off.

Gotcha! I'll poke around tomorrow afternoon!
is there anything else i should be looking for specifically, while i'm down near the intakes?

Also, how would i know if injectors are bad? i know you can test if they squirt fuel, but i don't wanna get fuel all over my bay :

Again thanks for your time!

[VinnyBay]

Originally Posted by W37V

no its not. it cases bunch of issues (low power, unable to rev to redline, poor fuel economy, etc) BUT, it's not that difficult to fix as diy. maybe 3 hours start to finish.

Mmmm the only thing i really experience is the "low power" part. But this only really happens when A/C is on, and when i try and get up to highway speeds. I have to fight it for it to literally get going... it even has to kick down a gear because there's so much "strain"

I've watched a video on the eccentric shaft sensor, and im going to check tomorrow to see if there is oil on the connector. If there is then 3 hours for a sensor we go!

Thanks for the recommendation!

[E92William]

Idk what else you could look for while by the intake. You can go and look between the runners and see how the pcv hose which is gonna be right under looks. Also this very hose has like a rubber foam ish cover around it where it connects to the valve cover. If this hose is cracked and seeping pcv oil you can tell by lightly squeezing it if it's dry it's good if it has oil you need a new hose.

What I meant by the injectors was that if you swapped them around and the lean code went from bank 2 to bank 1 you'd already know what's bad. Get yourself an android phone and see if it wants to work with your obd scanner if so use the app because there might be a vanos or valvetronic shadow code hidden in there.

[VinnyBay]

Originally Posted by E92William

Idk what else you could look for while by the intake. You can go and look between the runners and see how the pcv hose which is gonna be right under looks. Also this very hose has like a rubber foam ish cover around it where it connects to the valve cover. If this hose is cracked and seeping pcv oil you can tell by lightly squeezing it if it's dry it's good if it has oil you need a new hose.

What I meant by the injectors was that if you swapped them around and the lean code went from bank 2 to bank 1 you'd already know what's bad. Get yourself an android phone and see if it wants to work with your obd scanner if so use the app because there might be a vanos or valvetronic shadow code hidden in there.

Update, so i didn't realize this at first but the eccentric sensor is, what i assume is, oil leaking out from it. Also there is new oil pooling up near cylinder 3. I assume that is the eccentric motor seal already bad.
Second, all the coils are bosch, but they are different when it comes to the material and end plug pattern. the four of the six "bosch" coils have what looks like holes in the inside of the coils where it meets the spark plug.

As far as damage goes, i don't see any oil in the coils / spark plugs.
Could those two things going bad indicate still indicate idle situation? instead of the injectors?

[E92William]

My fuel trims were never perfect until I replaced that seal which was leaking oil though only into around cylinder 1. I I doubt it's just that but the seal is very cheap at a bmw dealer so do it

[VinnyBay]

Running out of hope boys,

So far, after checking intake for leaks (intake grill, back though to the throttle body) i've identified nothing out of the ordinary.

Swapped Bank 2 with Bank 1 injectors and, made sure they were doing their duty and not gummed up.

Checked Coils, as stated before, 4 out of the 6 coils had weird corrosion near the contacts. I moved them all to the front and moved the two good ones towards the back to see if idle sound changed. it didn't

Checked Plugs, they seemed good, no abnormal build up or anything. nothing in the spark plug holes, no build up of oil or anything

Open Engine bay, idle

There might be leak some where else, did some digging and after i started the car up after doing all this, there was an audible squeak and went away as temps rose to normal

Closed Engine bay, idle

If anything this is the most concerning part., the throbbing ^

[W37V]

In your "open engine bay" video, around 17 mark, also in your "right wheel idle" video, it almost sounds like you have an exhaust leak.

[Efthreeoh]

Did you actually pull the connector off the ESS and inspect for oil inside the connector? The seal round the ESS is obviously failing so oil has probably seeped into the ESS connector.

Now the issue I see is you have leaks all over the valve cover, at the Valvetronic gasket, and ESS, which indicates positive pressure in the cam box (i.e. under the valve cover). So I'd consider the Crank Case Vent (CCV) has an issue, especially at 200,000. If your starter is getting weak, then you have to pull the intake to replace it, which means you'll break most of the hoses in the CCV, so just get the CCV parts kit and replace it when replacing the starter. And if the ESS has oil contamination, you'll be replacing the valve cover gasket set anyway.

[E92William]

When I replaced the o ring in my ess it had a bit of oil in the connector but I just got a q tip and sucked all of it up. No issues. I think buddy over here is gonna have to do a smoke test on the car. If you're still getting a lean code that's your only clue.

You could actually swap over the two primary o2 sensors though I HIGHLY doubt that's what's bad, if you feel like ruling that out.

[bluewater328]

Originally Posted by Efthreeoh

Did you actually pull the connector off the ESS and inspect for oil inside the connector? The seal round the ESS is obviously failing so oil has probably seeped into the ESS connector.

Now the issue I see is you have leaks all over the valve cover, at the Valvetronic gasket, and ESS, which indicates positive pressure in the cam box (i.e. under the valve cover). So I'd consider the Crank Case Vent (CCV) has an issue, especially at 200,000. If your starter is getting weak, then you have to pull the intake to replace it, which means you'll break most of the hoses in the CCV, so just get the CCV parts kit and replace it when replacing the starter. And if the ESS has oil contamination, you'll be replacing the valve cover gasket set anyway.

This. I've never seen an ESS so oil-logged it was seeping outside. Seal is gone and almost definitely the sensor.

[VinnyBay]

Originally Posted by Efthreeoh

Did you actually pull the connector off the ESS and inspect for oil inside the connector? The seal round the ESS is obviously failing so oil has probably seeped into the ESS connector.

Now the issue I see is you have leaks all over the valve cover, at the Valvetronic gasket, and ESS, which indicates positive pressure in the cam box (i.e. under the valve cover). So I'd consider the Crank Case Vent (CCV) has an issue, especially at 200,000. If your starter is getting weak, then you have to pull the intake to replace it, which means you'll break most of the hoses in the CCV, so just get the CCV parts kit and replace it when replacing the starter. And if the ESS has oil contamination, you'll be replacing the valve cover gasket set anyway.

I already checked the eccentric shaft sensor, and i didn't see anything out of the ordinary. In the plug or in the socket, But there was a little bit of oil on the socket. Nothing was covered or caked by oil though, the yellow gasket round the plug, looked pretty new to be honest :

Could a bad CCV really cause the engine to sound like the second video?
If so i might have to replace all of that when i get my new starter.

Might go look around some part out listing to see if could pull some parts of them

[VinnyBay]

Originally Posted by E92William

When I replaced the o ring in my ess it had a bit of oil in the connector but I just got a q tip and sucked all of it up. No issues. I think buddy over here is gonna have to do a smoke test on the car. If you're still getting a lean code that's your only clue.

You could actually swap over the two primary o2 sensors though I HIGHLY doubt that's what's bad, if you feel like ruling that out.

same here, there wasn't much oil in mine, i just used a Q tip with some rubbing alcohol to clean the connectors just in case.

I mean the car does have a confirmed code for the Post Cat trim sensor, but again still using the generic code reader. I might take it to a bmw trained tech, to read the codes / do a smoke test for me. I Wonder how much they'd charge me for that :

[E92William]

100 bucks or so is standard diagnostic at a bmw Indy shop. I'd replace that o2 sensor if you're getting a code for it. As far as I'm concerned secondary o2s don't have effect on fuel trims but it might be different on bmws. When my pcv failed stuck closed my car would sound like a diesel and stall after driving for a while, it would improve idle and such if you opened the oil fill cap while running, try that.

[tlow98]

Originally Posted by VinnyBay

I already checked the eccentric shaft sensor, and i didn't see anything out of the ordinary. In the plug or in the socket, But there was a little bit of oil on the socket. Nothing was covered or caked by oil though, the yellow gasket round the plug, looked pretty new to be honest :

Could a bad CCV really cause the engine to sound like the second video?
If so i might have to replace all of that when i get my new starter.

Might go look around some part out listing to see if could pull some parts of them

If there is oil on the socket, ok the connection where the plug goes onto the sensor then it has failed and will need to be replaced.

[VinnyBay]

Originally Posted by E92William

When my pcv failed stuck closed my car would sound like a diesel and stall after driving for a while, it would improve idle and such if you opened the oil fill cap while running, try that.

Mmmm it wouldn't happen to sound like this would it, when you opened the oil cap? cuz i think we found our problem. The pulsating noise stops after i open the oil cap, but comes back when i close it.

Also i don't know if they really matters but i forgot to mention that, when i got my car serviced at BMW a couple of months ago, they replaced some sort of heater, is it the PCV they replaced?