N52 stalling problems

[Garbagio]

Accidentally posted this in the 1M forum first, oops

Hi guys, sorry if this has already been solved, but I’ve been lurking in here a while and not been able to find a solution.

So my car started messing up a few months back, first it would be a little hiccup at around 3000 rpm, like I tapped my brakes for a split second. It slowly happened more and more often until finally it threw me into a DSC limp mode.

I replaced the crankshaft sensor when that gave me a code. When that didn’t work I replaced the camshaft sensors because those codes were being thrown, that didn’t work either. I read that it might be my vanos solenoids so I replaced both of them and that hasn’t worked.

What is happening now is that my car will be fine on startup and will drive for about 10ish minutes or until the oil heats up. It will hiccup, like for a split second there’s no fuel and then the car makes up for it by sending too much fuel. If I’m not in neutral, it feels like as I’m driving that I jam hard on my breaks for a split second, or the car will just shut off even when I’m in gear and I lose power steering and acceleration. I would deal with it if it didn’t do this at highway speeds.

There is one time when the car will run okay, if it stutters enough without stalling it will kick into the DSC limp mode, where I won’t have much acceleration, but at least the car runs. This makes me think this is an issue with a sensor and not necessarily any mechanical problems. It’s also kind of hard to get a code, unless it goes into DSC mode, when it stutters it will show an SES for a split second before going away, and that disappears if I shut the engine off and turn it back on.When I do get a code it’s still showing camshaft sensors, crankshaft sensor, or both.

Have I just been really unlucky and got crappy sensors from oreillys this whole time? I’m just mad that I’ve sank a lot of money in this car and I can’t even drive it safely on a highway.

Thanks for your guys’ help

[///Makis]

Originally Posted by Garbagio

Accidentally posted this in the 1M forum first, oops

Hi guys, sorry if this has already been solved, but I’ve been lurking in here a while and not been able to find a solution.

So my car started messing up a few months back, first it would be a little hiccup at around 3000 rpm, like I tapped my brakes for a split second. It slowly happened more and more often until finally it threw me into a DSC limp mode.

I replaced the crankshaft sensor when that gave me a code. When that didn’t work I replaced the camshaft sensors because those codes were being thrown, that didn’t work either. I read that it might be my vanos solenoids so I replaced both of them and that hasn’t worked.

What is happening now is that my car will be fine on startup and will drive for about 10ish minutes or until the oil heats up. It will hiccup, like for a split second there’s no fuel and then the car makes up for it by sending too much fuel. If I’m not in neutral, it feels like as I’m driving that I jam hard on my breaks for a split second, or the car will just shut off even when I’m in gear and I lose power steering and acceleration. I would deal with it if it didn’t do this at highway speeds.

There is one time when the car will run okay, if it stutters enough without stalling it will kick into the DSC limp mode, where I won’t have much acceleration, but at least the car runs. This makes me think this is an issue with a sensor and not necessarily any mechanical problems. It’s also kind of hard to get a code, unless it goes into DSC mode, when it stutters it will show an SES for a split second before going away, and that disappears if I shut the engine off and turn it back on.When I do get a code it’s still showing camshaft sensors, crankshaft sensor, or both.

Have I just been really unlucky and got crappy sensors from oreillys this whole time? I’m just mad that I’ve sank a lot of money in this car and I can’t even drive it safely on a highway.

Thanks for your guys’ help

I think people will need more info.

What year is your car?

Is it an N52 or N51?

Have you done any mods to it?

How many miles do you have?

What are you using to read codes?

Did you do any maintenance to the car before it started happening?

Based on your post I am assuming it's manual right?

If you're getting camshaft codes do you know if your car was part of the recall or had the recall done for vanos gear assembly bolts? I would think if the bolts failed you would be getting more than just ses lights that would go away after turning off and on but maybe?

When you say you get a stumble like the car seems like it's being fuel starved and then more dumped in makes me think it could be failing 02 sensors. If you have a scanner that can give you live data of a/f ratios for pre cat bank 1 and 2 see if anything looks out of the ordinary. When the car is warmed up and in park or neutral start reading the data and push the gas to like 2000 rpm and hold it there. You should see the numbers bouncing from positive to negative. A sign that your sensors are working is the a/f ratio is constantly trending toward 0. If you see one bank not doing that at all, or implausibly not following the other then that's could be a sign of a problem.

I'm not sure if it's possible at all but it's cheap to check and see but there are vanos solenoid filters that could get gummed up and give problems if you don't change your oil too often. I've only come across one instance where that had fixed a problem with idling as the filters were very clogged and not allowing adequate oil through. They are on oassange side of the engine at the front side and a pain to get to but you can remove them and clean them if you want. If you change your oil regularly I don't think that will be the case here.

Have you tried disconnecting the MAF sensor to see if that does anything? When disconnected the car runs in closed loop so if it fixes the problem then that could narrow down the culprits for this.


Otherwise I don't know of anything else would cause that but I'm also no expert by any means.

Also I would recommend buying parts from fcp euro, they have a lifetime guarantee on almost anything.

The parts you bought from oriellys, were they oem?




Pleased to hear,

[Garbagio]

Originally Posted by ///Makis

I think people will need more info.

What year is your car?

Is it an N52 or N51?

Have you done any mods to it?

How many miles do you have?

What are you using to read codes?

Did you do any maintenance to the car before it started happening?

Based on your post I am assuming it's manual right?

If you're getting camshaft codes do you know if your car was part of the recall or had the recall done for vanos gear assembly bolts? I would think if the bolts failed you would be getting more than just ses lights that would go away after turning off and on but maybe?

When you say you get a stumble like the car seems like it's being fuel starved and then more dumped in makes me think it could be failing 02 sensors. If you have a scanner that can give you live data of a/f ratios for pre cat bank 1 and 2 see if anything looks out of the ordinary. When the car is warmed up and in park or neutral start reading the data and push the gas to like 2000 rpm and hold it there. You should see the numbers bouncing from positive to negative. A sign that your sensors are working is the a/f ratio is constantly trending toward 0. If you see one bank not doing that at all, or implausibly not following the other then that's could be a sign of a problem.

I'm not sure if it's possible at all but it's cheap to check and see but there are vanos solenoid filters that could get gummed up and give problems if you don't change your oil too often. I've only come across one instance where that had fixed a problem with idling as the filters were very clogged and not allowing adequate oil through. They are on oassange side of the engine at the front side and a pain to get to but you can remove them and clean them if you want. If you change your oil regularly I don't think that will be the case here.

Have you tried disconnecting the MAF sensor to see if that does anything? When disconnected the car runs in closed loop so if it fixes the problem then that could narrow down the culprits for this.


Otherwise I don't know of anything else would cause that but I'm also no expert by any means.

Also I would recommend buying parts from fcp euro, they have a lifetime guarantee on almost anything.

The parts you bought from oriellys, were they oem?




Pleased to hear,

Alright to reply to that in order
It’s a 2008

I’m pretty sure it’s n52 from the research I’ve done in the past

All stock

~114k I bought it at ~80k

I’m using a fairly nice Amazon scanner, I forget what brand I’ll look later, it’s not mechanic grade but it can still read live data

No maintenance triggered it as far as I can remember, I was in between oil changes too, like I didn’t just do one but I also didn’t need one

Yes it’s a 6MT

I’ll double check on the recall, the only recall that’s happened while I’ve owned it is something with the heater core or fan? Something along the lines of that

Good tip on the 02 sensors, I will check it out tomorrow. I should’ve thought of that when it wasn’t happening on cold starts

As far as the oil, I’ve kept up on it pretty well, every 5k-7k or so. I can’t speak for the previous owner so that’s entirely plausible. When I’ve changed my oil I don’t notice any gunk or it being overly thick but hey I’ll take any suggestions at this point lol

Yes, the MAF was one of the first things I checked via disconnecting it, could it have become an issue in the time in between, maybe I’ll do it again for the kicks and giggles

I bought the highest quality parts/closest to oem that oreillys had, at the time I didn’t want to wait for parts from FCP euro but I guess after all this time I should’ve done that to start with just to be safe

Thanks for your suggestions, I’ll definitely look into some of those. I just miss driving my car and it sucks to have to be in a work truck for everything

[///Makis]

Originally Posted by Garbagio

Alright to reply to that in order
It’s a 2008

I’m pretty sure it’s n52 from the research I’ve done in the past

All stock

~114k I bought it at ~80k

I’m using a fairly nice Amazon scanner, I forget what brand I’ll look later, it’s not mechanic grade but it can still read live data

No maintenance triggered it as far as I can remember, I was in between oil changes too, like I didn’t just do one but I also didn’t need one

Yes it’s a 6MT

I’ll double check on the recall, the only recall that’s happened while I’ve owned it is something with the heater core or fan? Something along the lines of that

Good tip on the 02 sensors, I will check it out tomorrow. I should’ve thought of that when it wasn’t happening on cold starts

As far as the oil, I’ve kept up on it pretty well, every 5k-7k or so. I can’t speak for the previous owner so that’s entirely plausible. When I’ve changed my oil I don’t notice any gunk or it being overly thick but hey I’ll take any suggestions at this point lol

Yes, the MAF was one of the first things I checked via disconnecting it, could it have become an issue in the time in between, maybe I’ll do it again for the kicks and giggles

I bought the highest quality parts/closest to oem that oreillys had, at the time I didn’t want to wait for parts from FCP euro but I guess after all this time I should’ve done that to start with just to be safe

Thanks for your suggestions, I’ll definitely look into some of those. I just miss driving my car and it sucks to have to be in a work truck for everything

Yeah I know what you mean on the waiting. But fcp is really quick with shipping if you live on the east coast but your profile says you're in Cali I get the frustration part when you want something fixed ASAP. But it's better to narrow down the problem than throw parts at it because someone on the forum said they had a problem and fixed it.

If your scanner can real bmw specific codes it should be fine.

Try driving the car for like a little while without the maf sensor and see if it still does it, it will 100% throw an SES after it's warmed up, but if you don't see the same stumbling you mentioned, like you said it's more than likely a sensor than mechanical.

When you changed the camshaft sensor, did you notice oil underneath the sensor when you took it off?

Also post the actual codes if you remember them or can pull them again, it might help someone else in the future.