[JonOhh]

Hi all,

2006 330i, 6MT, 100k MI

The other night I noticed some pretty audible (with the windows down) low speed pre ignition, at around 2000-2500 RPM, I heard a brief ping as I tipped in to about 50% throttle, and then a few more pings as I immediately got off the throttle to stop the LSPI.

Of course, I should probably be at higher revs before giving it a lot of throttle as the obvious solution, but is it normal for the N52 to do this? The car runs fine otherwise, butter smooth, good power, and it has brand new OEM plugs. I occasionally get a raised idle, but no codes or warnings to indicate anything is wrong.

With my other car being loud and having a turbo, I'm used to never hearing any preignition or detonation whatsoever, so I'm not sure how much is normal for an N/A motor.

Edit: just to add, running Shell 93. Haven't noticed any... new...issues with the other car, filled up within the same week from the same station.

Thanks in advance.

[juld0zer]

Yours is an 06, so original N52 (silver top). I am familiar with all the peculiarities you mentioned and I believe it is all just characteristic of this generation of N52. The high idle and the fluctuating coolant temps are just some of the mysteries. You can even connect the VANOS solenoids incorrectly and it won't trigger the EML!

Anyway, back on topic. I don't believe it is LSPI. LSPI is a fairly recent term and only really affects direct injection petrol engines, particularly those with turbos.
My belief is they redesigned the oil supply system on the black top engines for this reason. The standard method of oil pressure control/delivery is not sufficient for dual VVT in this engine. The N52K has a variable delivery oil pump so it is capable of more volume at low RPM. Essentially, I believe the noise is actually from a lack of oil supply to the VANOS adjusters at low RPM but moderate to high load situations. What oil and oil viscosity do you use?

[JonOhh]

Originally Posted by juld0zer

Yours is an 06, so original N52 (silver top). I am familiar with all the peculiarities you mentioned and I believe it is all just characteristic of this generation of N52. The high idle and the fluctuating coolant temps are just some of the mysteries. You can even connect the VANOS solenoids incorrectly and it won't trigger the EML!

Anyway, back on topic. I don't believe it is LSPI. LSPI is a fairly recent term and only really affects direct injection petrol engines, particularly those with turbos.
My belief is they redesigned the oil supply system on the black top engines for this reason. The standard method of oil pressure control/delivery is not sufficient for dual VVT in this engine. The N52K has a variable delivery oil pump so it is capable of more volume at low RPM. Essentially, I believe the noise is actually from a lack of oil supply to the VANOS adjusters at low RPM but moderate to high load situations. What oil and oil viscosity do you use?

Hi Juld0zer,

Currently using Mobil 1 Extended Performance 0w40. I get the occasional lifter tick if I let it idle too long near the end of the 5,000 MI OCI, but I don't expect any different from the OG N52.

What you said makes much more sense, I was pretty surprised to hear something that sounds exactly like LSPI, and so I assumed that's what it was.

If the cause is poor oil supply under those conditions, I'd also worry about what that might mean for the bearings (especially the rod bearings), is this a concern for these early engines, or is the potential for VANOS to rattle around the extent of the concerns?

Thank you much, it's greatly appreciated!
Jon

[rjahl]

Originally Posted by JonOhh

Hi Juld0zer,

Currently using Mobil 1 Extended Performance 0w40. I get the occasional lifter tick if I let it idle too long near the end of the 5,000 MI OCI, but I don't expect any different from the OG N52.

What you said makes much more sense, I was pretty surprised to hear something that sounds exactly like LSPI, and so I assumed that's what it was.

If the cause is poor oil supply under those conditions, I'd also worry about what that might mean for the bearings (especially the rod bearings), is this a concern for these early engines, or is the potential for VANOS to rattle around the extent of the concerns?

Thank you much, it's greatly appreciated!
Jon

You did not mention if you had any modifications or engine tunes.

The factory tune is vary sensitive to engine noises and the knock sensors values will have the DME pulling timing well before you hear anything. It even predicts knocks from past history and uses load management to control timing when the load suddenly increases.

If you have a tune from some wildcat tuner then those systems could have been altered.

[juld0zer]

Originally Posted by rjahl

You did not mention if you had any modifications or engine tunes.

The factory tune is vary sensitive to engine noises and the knock sensors values will have the DME pulling timing well before you hear anything. It even predicts knocks from past history and uses load management to control timing when the load suddenly increases.

If you have a tune from some wildcat tuner then those systems could have been altered.

This engine is outside of the faulty VANOS actuator period. I checked mine when I replaced my rocker cover gasket and there were no issues. If anything, the head was amazingly clean for its age. The N52K engines seem to sludge up a lot more. Perhaps the external PCV does a better job? Or the lower average coolant temperatures of the N52 may reduce cylinder head temps overall so any crud doesn't crust up?
You can install the latest version of the VANOS adjusters but they are expensive. I am unsure if they will be quieter in operation or have lower oil supply requirements.

Rjahl, I have always been suspicious of the sensitivity of the knock detection system. Mine is a manual and the gearbox rollover noise used to be really noticeable. I can't rule out the DMF although I replaced it last year along with a new clutch. It reduced some noise and whatever remained was largely rollover noise. Still quieter than my 370Z though, by far. I think the DMF could do a better job at smoothening out the engine (so much for an inline 6).
I suspected false knock detection because every time I reset oktanzahl adaptations in INPA it goes like a scalded cat, instantly. The effect fades over the course of 2-3 tanks. I am using the highest octane fuel available here (98) and tried all brands so it's not a fuel or fuel supply issue as I also tested with the fuel pump running at max output.
In summer when I use the AC (ambients up to 45*c), I was surprised at how much smoother everything was and how much better the engine seemed to accelerate. This DME/engine doesn't have any efficientdynamics control so the alternator and compressor are not disabled on heavy acceleration. I believe a combination of the increased idle speed (750 vs 650rpm) and the compressor's load acting as a damper helps to smoothen the engine, reducing the DMF's workload and also reducing take off judder at the same time. I believe the DME may have been seeing false knock from the clutch judder and gearbox noise in the takeoff RPM range and retarded timing ignition timing in that range as a result, which can cause flat spots and poor in gear acceleration in those RPMs.

The final thing I did was change the gearbox oil which allowed for much smoother and damped shifts, which again reduces the DMF's work while improving shifting comfort.

The 'pinging' sound is well documented/reported on this forum and many others. I also believe that this may not be beneficial to the false knock issue. I have come to accept it as being characteristic. You can only hear it with the windows down anyway. For the record, I use Shell Helix Ultra (same as Pennzoil platinum) 5w30 LL01 oil and it did it with 0w40 Valvoline Synpower LL01 aswell. VANOS solenoids and check valves are all new, genuine parts. Oil filter is genuine and the lid core is intact. I also have no lifter tick, not even after parking it for more than a couple of days.

[JonOhh]

Should have mentioned, the car is completely stock. I'm new to this platform and still learning about the MSV70, but have experience with fiats knock control strategy which I imagine is somewhat similar.

Thanks for the input.
Jon

[rjahl]

Originally Posted by juld0zer

This engine is outside of the faulty VANOS actuator period. I checked mine when I replaced my rocker cover gasket and there were no issues. If anything, the head was amazingly clean for its age. The N52K engines seem to sludge up a lot more. Perhaps the external PCV does a better job? Or the lower average coolant temperatures of the N52 may reduce cylinder head temps overall so any crud doesn't crust up?
You can install the latest version of the VANOS adjusters but they are expensive. I am unsure if they will be quieter in operation or have lower oil supply requirements.

Rjahl, I have always been suspicious of the sensitivity of the knock detection system. Mine is a manual and the gearbox rollover noise used to be really noticeable. I can't rule out the DMF although I replaced it last year along with a new clutch. It reduced some noise and whatever remained was largely rollover noise. Still quieter than my 370Z though, by far. I think the DMF could do a better job at smoothening out the engine (so much for an inline 6).
I suspected false knock detection because every time I reset oktanzahl adaptations in INPA it goes like a scalded cat, instantly. The effect fades over the course of 2-3 tanks. I am using the highest octane fuel available here (98) and tried all brands so it's not a fuel or fuel supply issue as I also tested with the fuel pump running at max output.
In summer when I use the AC (ambients up to 45*c), I was surprised at how much smoother everything was and how much better the engine seemed to accelerate. This DME/engine doesn't have any efficientdynamics control so the alternator and compressor are not disabled on heavy acceleration. I believe a combination of the increased idle speed (750 vs 650rpm) and the compressor's load acting as a damper helps to smoothen the engine, reducing the DMF's workload and also reducing take off judder at the same time. I believe the DME may have been seeing false knock from the clutch judder and gearbox noise in the takeoff RPM range and retarded timing ignition timing in that range as a result, which can cause flat spots and poor in gear acceleration in those RPMs.

The final thing I did was change the gearbox oil which allowed for much smoother and damped shifts, which again reduces the DMF's work while improving shifting comfort.

The 'pinging' sound is well documented/reported on this forum and many others. I also believe that this may not be beneficial to the false knock issue. I have come to accept it as being characteristic. You can only hear it with the windows down anyway. For the record, I use Shell Helix Ultra (same as Pennzoil platinum) 5w30 LL01 oil and it did it with 0w40 Valvoline Synpower LL01 aswell. VANOS solenoids and check valves are all new, genuine parts. Oil filter is genuine and the lid core is intact. I also have no lifter tick, not even after parking it for more than a couple of days.

You can log the knock sensors as I have using TestO and maybe Bimmergeeks tools.

Back when I was tuning my N52, I logged timing and knock values. I am certain that this engine is very sensitive to noises.

But not random noises, the DME listens to only specific frequencies and only at specific crank angles. Levels are compared against allowable values for RPM and load. Two sensors listen to each bank of cylinders.

The DME will cut timing in two ways, soft knock and hard knock. Each triggers a different cut in timing. Both of these knock values are well below the threshold of human hearing.

I found that I could reduce the sensitive by a few percent and the timing adaptation would not get so screwy.

It's unlikely that a stock motor will have audible pinging unless your are running really crappy fuel.

[JonOhh]

Originally Posted by juld0zer

This engine is outside of the faulty VANOS actuator period. I checked mine when I replaced my rocker cover gasket and there were no issues. If anything, the head was amazingly clean for its age. The N52K engines seem to sludge up a lot more. Perhaps the external PCV does a better job? Or the lower average coolant temperatures of the N52 may reduce cylinder head temps overall so any crud doesn't crust up?
You can install the latest version of the VANOS adjusters but they are expensive. I am unsure if they will be quieter in operation or have lower oil supply requirements.

Rjahl, I have always been suspicious of the sensitivity of the knock detection system. Mine is a manual and the gearbox rollover noise used to be really noticeable. I can't rule out the DMF although I replaced it last year along with a new clutch. It reduced some noise and whatever remained was largely rollover noise. Still quieter than my 370Z though, by far. I think the DMF could do a better job at smoothening out the engine (so much for an inline 6).
I suspected false knock detection because every time I reset oktanzahl adaptations in INPA it goes like a scalded cat, instantly. The effect fades over the course of 2-3 tanks. I am using the highest octane fuel available here (98) and tried all brands so it's not a fuel or fuel supply issue as I also tested with the fuel pump running at max output.
In summer when I use the AC (ambients up to 45*c), I was surprised at how much smoother everything was and how much better the engine seemed to accelerate. This DME/engine doesn't have any efficientdynamics control so the alternator and compressor are not disabled on heavy acceleration. I believe a combination of the increased idle speed (750 vs 650rpm) and the compressor's load acting as a damper helps to smoothen the engine, reducing the DMF's workload and also reducing take off judder at the same time. I believe the DME may have been seeing false knock from the clutch judder and gearbox noise in the takeoff RPM range and retarded timing ignition timing in that range as a result, which can cause flat spots and poor in gear acceleration in those RPMs.

The final thing I did was change the gearbox oil which allowed for much smoother and damped shifts, which again reduces the DMF's work while improving shifting comfort.

The 'pinging' sound is well documented/reported on this forum and many others. I also believe that this may not be beneficial to the false knock issue. I have come to accept it as being characteristic. You can only hear it with the windows down anyway. For the record, I use Shell Helix Ultra (same as Pennzoil platinum) 5w30 LL01 oil and it did it with 0w40 Valvoline Synpower LL01 aswell. VANOS solenoids and check valves are all new, genuine parts. Oil filter is genuine and the lid core is intact. I also have no lifter tick, not even after parking it for more than a couple of days.

The DMF on these cars seems to be loud, and it's pretty impressive how it transmits its chatter throughout the entire engine block. Mine does the normal chatter everyone talks about that stops once the clutch is depressed, and the secondary sort of rattle regardless of clutch position that sounds like it's coming from under the middle of the intake manifold (not completely sure if this noise is the DMF, but judging from other threads, that noise is normal for the N52.

Knock sensor values can be read through INPA right? Im trying to get my hands on a cable to do some logs, and do a general checkup. I was searching specifically for things pre ignition related, so that possibly explains not finding it in my previous search attempts.

Mine only starts lifter ticking if it idles for more than 20 or so minutes from a cold start (which is horrible for it anyway so, it's avoided at all costs.) A quick run up to 4000 a few times and it's back to silent. And as far as the AC, I have noticed that too. For me the extra 100rpm or so also smooths out the idle a ton- enough to not be able to tell it's running VS the constant idle vibration with AC off.

Sorry for digressing from my own thread a bit, but there's loads of good information here so, cheers.

EDIT: Rjahl answered some of my questions while I was typing this post.

Jon

[juld0zer]

Originally Posted by rjahl

You can log the knock sensors as I have using TestO and maybe Bimmergeeks tools.

Back when I was tuning my N52, I logged timing and knock values. I am certain that this engine is very sensitive to noises.

But not random noises, the DME listens to only specific frequencies and only at specific crank angles. Levels are compared against allowable values for RPM and load. Two sensors listen to each bank of cylinders.

The DME will cut timing in two ways, soft knock and hard knock. Each triggers a different cut in timing. Both of these knock values are well below the threshold of human hearing.

I found that I could reduce the sensitive by a few percent and the timing adaptation would not get so screwy.

It's unlikely that a stock motor will have audible pinging unless your are running really crappy fuel.

Which tuner were you using or was it just a solo project? Happy to take this tangent to PM if you prefer as I would love to turn down the knock sensitivity and have my scolded cat all day long

[rjahl]

Self tune, mostly.

This is a hobby so I don't mind discussing things in the open.

Are you doing any tuning yourself? Do you have the tools? Bimmerlabs can help with the DME unlock and the flashing part.

You run the MSV80 while my files are for the MSV70, virtually the same tuning set up but the files/maps are in a different format for the Tricore processor. Bite swapped in many places. I translated most of the main maps for the MSV80 a long time ago but dropped the project when Chris starting writing his scripts to make the translations.

I need to "ping" him and see if he has any plans to make those public.

[JonOhh]

Don't worry at all about derailing anything, if y'all want to use this thread to discuss this, and also as a place for more people to chime in, feel free. I'm also very interested in this for the future.


In the tuned turbo Fiat world, we have an issue where the ECU tends to get permanently (until adaptations are reset) "scared" by a period of increased knock readings, and dials things back down quite harshly, even though it may be a rare case or no longer occuring. All in all, it results in very similar behavior where it runs great after a reset, but as the miles add up and knock gets picked up (whatever the cause, false or not), the car eventually detunes itself quite bad- just like these cars seemingly do.

Now of course to an extent this is necessary in order for the ECU/DME to prevent a knock event in the future, before it happens, but I think there's a lot of headroom that could be utilized in order to get a more consistent and overall better performing car.


Jon

[juld0zer]

Mine is an MSV70 also.

Apologies to Jon for going off on a tangent but appreciate the open discussion here.
I believe that like fuel trims, there are probably the equivalent of STFT (to deal with sudden ping) and LTFT (to fine tune the knock control). The Subaru guys seem to discuss it a lot but their ECU might be more readily accessible in terms of cracking it and reflashing it. By comparison, there is hardly any discussion of it here.

Just as an update on the sporadic flat spots/dull acceleration caused by what I believe is the detection of false knock, I increased the base idle speed to 750rpm. I mentioned earlier the car performed remarkably better with the AC on, even in summer it would accelerate better with the AC on. It was like the AC on button was the sport mode. AC on means the idle speed increases by 100rpm to counter the compressor load. I raised the idle as an experiment to see if the higher idle speed or the compressor load was helping to smoothen the running of the engine. After a couple of days, the results are positive.

Before all this, there was noticeable vibration from the engine like something was out of balance around 1200-1600rpm. It was a rumble that followed engine speed. It was difficult to modulate the engine speed using the gas pedal. Now it is smooth, easy to modulate in increments of 100rpm. Easy to rev up the engine to takeoff speed, which also avoids real clutch judder. Gearbox rollover noise (cement mixer sound) is almost inaudible. Not even a new DMF fixed it. Perhaps the DMF manufacturer did their testing and calibration with AC on, assuming all BMW drivers drive with the AC on? I thought straight 6 engines are supposed to be silky smooth? A cup of coffee probably wouldn't stay on top of the engine!
Acceleration is even better now without the load of the AC compressor. I have to be careful in the wet now as it can light up the rears in the dry again
At the normal base idle speed of 650rpm, the firing impulses must be too much for the DMF to handle so it becomes even worse when taking off.

Or maybe something is affecting the idle quality of my engine, like sticky injectors? There is only two things that balance the crank impulses - the DMF or harmonic damper pulley. Interestingly, the automatic transmission cars use a much larger/heavier pulley than the manual cars. They are interchangeable so I might pull one off a wrecker car and test it at the expense of duller throttle response.
I have never heard an N52K have any rollover noise or rumble. They also seem much more keen to respond to throttle blips.

Has anyone tried 10w30/40 oil to cure the 'pinging' noise?

[Phil325i]

Interested to know how you increased your base idle speed. Presumably a software tweak..?

[juld0zer]

For MSV70 (Silver engine cover) it can only be done in ISTA/D. I couldn't get INPA to do it but I believe MSV80 can be done in INPA. The menu is there in INPA but none of the functions worked.

In ISTA you can temporarily increase it or permanently increase it. I assume it is also possible for N54 as people often increase the idle speed to counter NVH from solid flywheels or stiff engine mounts

[PhaseP]

Originally Posted by juld0zer

My belief is they redesigned the oil supply system on the black top engines for this reason. The standard method of oil pressure control/delivery is not sufficient for dual VVT in this engine. The N52K has a variable delivery oil pump so it is capable of more volume at low RPM. Essentially, I believe the noise is actually from a lack of oil supply to the VANOS adjusters at low RPM but moderate to high load situations. What oil and oil viscosity do you use?

N52 from start had "volume flow controlled" oil pump, it didn't change between N52 and N52K:

https://www.newtis.info/tisv2/a/en/e...ve-msv/1poWb2I

I never heard any pinging with my engine 06 N52. I do get the sticky lifter tapping from time to time. Nor my idle had been noisey, manual transmission. The only two times I had idle problems were when my MAF connector was dirty and didn't provide good electrical connection and when I had a vacuum leak at one of the pcv air connections after starter replacement.

[juld0zer]

N52K had the electronically map controlled pump, similar to the N55. I believe newtis hasn't got every single link mapped correctly.

The 'pinging' noise is only audible with the windows down and particularly when accelerating near a wall. You're a lucky one Are you the original owner? What oil and filter do you use?

I'm currently experiencing a constant light rumble through the car with the 750rpm idle. I will try increments of 10rpm to see when the rumble goes away.

I did the MAF connector repin after your post. Not sure why but every time i disconnect the MAF sensor and reconnect it, it's like the adaptations get reset. So I've unscrewed the MAF sensor from the housing whenever I need to remove the airbox or intake ducting instead, to avoid adding another variable.

So far the increased idle speed has yielded the most consistent throttle response off the line and in gear. It just pulls and pulls as long as the engine is above 1900rpm

[PhaseP]

I am the original owner. The volume flow controlled oil pump is described and mentioned in very early n52 engine documentation, it was one of the features of this engine when originally bmw released it. Similar to electric water pump. Oil pump is the same part number through out the n52 engines.

[juld0zer]

https://www.newtis.info/tisv2/a/en/f10-530i-lim/wiring-functional-info/power-train/engine-electronics-msv/engine-oil/oil-pressure-sensor/Y4YOM3Z

The map control aspect extends on the capability of the existing pump by allowing full electronic control of the oil delivery. This can reduce fuel consumption by further reducing pump output and perhaps it might also improve oil supply to the VANOS adjusters.

I'll see if my increased base idle reduces the occurence of the 'pinging' sound although I doubt it will improve as the sound usually occurs on a sudden load change, eg. re-accelerating after slowing for a roundabout.

[scanspeak]

Originally Posted by juld0zer

Or maybe something is affecting the idle quality of my engine, like sticky injectors? There is only two things that balance the crank impulses - the DMF or harmonic damper pulley. Interestingly, the automatic transmission cars use a much larger/heavier pulley than the manual cars. They are interchangeable so I might pull one off a wrecker car and test it at the expense of duller throttle response.
I have never heard an N52K have any rollover noise or rumble. They also seem much more keen to respond to throttle blips.

Has anyone tried 10w30/40 oil to cure the 'pinging' noise?

My 2007 N52 demonstrates none of the noise issues you describe. I can barely tell it's running at idle and she revs like a sewing machine. I think you have an issue somewhere with your engine.

[rjahl]

Originally Posted by juld0zer

https://www.newtis.info/tisv2/a/en/f10-530i-lim/wiring-functional-info/power-train/engine-electronics-msv/engine-oil/oil-pressure-sensor/Y4YOM3Z

The map control aspect extends on the capability of the existing pump by allowing full electronic control of the oil delivery. This can reduce fuel consumption by further reducing pump output and perhaps it might also improve oil supply to the VANOS adjusters.

I'll see if my increased base idle reduces the occurence of the 'pinging' sound although I doubt it will improve as the sound usually occurs on a sudden load change, eg. re-accelerating after slowing for a roundabout.

Since you are so concerned with your oil pressure, have you tried logging it? Or logging other parameters while you are there?

[JonOhh]

If I remember right, my 06 330i, since I've gotten it, has sometimes made a slight single "clink" noise at heavy throttle low rpm. Originally assumed it was the exhaust flapper... flapping... but I've unplugged the solenoid and it's still there.

Most of the time, my n52 doesn't rattle or clunk under acceleration at all- it's actually remarkably smooth and quiet, but occasionally there's this sound we're currently talking about, and I really want to know what it is.

I remember reading a long time ago that there was once a flash to help alleviate the lifter issues, which put the oil pump in a higher output state at lower rpm/idle. I will keep trying to find the thread, but the owner reported that it resolved his lifter tick issues. My logic is, if it is the VANOS not getting the oil pressure it needs, this would also alleviate that as well, and hopefully silence it.

On top of that, I'm willing to sacrifice some efficiency for the peace of mind that oil pressure, even during low rpm operation, is more than sufficient to keep all of the engine propperly lubricated.

As said before, I'll keep trying to find it, but for now I have no concrete validation that this update exists.

Jon

[PhaseP]

Originally Posted by juld0zer

https://www.newtis.info/tisv2/a/en/f10-530i-lim/wiring-functional-info/power-train/engine-electronics-msv/engine-oil/oil-pressure-sensor/Y4YOM3Z

The map control aspect extends on the capability of the existing pump by allowing full electronic control of the oil delivery. This can reduce fuel consumption by further reducing pump output and perhaps it might also improve oil supply to the VANOS adjusters.

I'll see if my increased base idle reduces the occurence of the 'pinging' sound although I doubt it will improve as the sound usually occurs on a sudden load change, eg. re-accelerating after slowing for a roundabout.

The link you have is for N53 engine. For the oil pump to be electronically controlled it needs a electromechanical element. On N53 and N55 there is an oil pressure regulator valve that does this, according to the link you provided and others I saw. This valve is attached on the left side (exhaust) of the engine block from the drawings.

Looking at realoem.com, except N53 engines, there is only a limited number of N52's that has this actuator valve. And those are E90 325i/xi N52 Euro model with CO2 (S1CBA) package, which is probably real 2.5 litre engine, and USA 328XI E92 LCI with CO2 (S1CBA) package.

In E9X, none of the other N52's have this actuator valve, regardless of year or model. So they all have the same oil pump, silver or black engine cover, with the above exceptions.