Has anyone lost or secured their oil pump nut? Does it come from the factory with thread locker?

[LivesNearCostco]

Didn't know if this should go in Maintenance, Troubleshooting, or Performance, so feel free to move to the appropriate forum. I tried searching but only found a suggestion to keep the revs below 6000.

E46 fanatics with the 330/M5430 engine report running it a lot above 6000RPM can set up bad harmonics and vibrate the oil pump sprocket nut loose. No sprocket --> no oil pressure --> blown motor. In the worst case the sprocket shaft shears off. The recommended fixes seem to be:

1) Safety wire, Loc-tite, or tack weld the nut in place. Bimmerworld sells a drilled nut with safety wire (http://store.bimmerworld.com/m50-drilled-oil-pump-nut-p640.aspx).
2) Replace nut and shaft with VAC motorsports upgrade kit (http://www.vacmotorsports.com/catalog/vac---m52tum54tu-oil-pump-upgrade-kit.htm)
3) Replace whole oil pump with more expensive design, or go to a dry sump system
4) Replace harmonic damper with new OEM one or upgraded ATI Super Damper.
5) Don't spend much time >6,000 RPM

It's definitely happened to other E46 330 drivers (and probably a bunch of E36 racers), but I also heard the ZHP oil pump nut comes with thread locker already applied at the factory. Have any of you...

1) Verified the ZHP oil pump nut already has threadlocker on it?
2) Upgraded your oil pump, or upgraded the sprocket and shaft?
3) Safety wired, tack welded, or applied thread locker to your oil pump nut?
4) Lost oil pressure because the oil pump nut came off?
5) Replaced or upgraded your harmonic damper?
6) Decided that I'm nuts for worrying about this nut when I don't race?

[danewilson77]

The ZHP is verified to have the upgraded nut.

I honestly don't think you have much to worry about.

HTC Thunderbolt+TT

[nk_zhp]

Haven't heard about this on ZHP cars. I also do recall reading that because of the slightly increased rev limit the pump comes with a thread lock applied.

This thread is actually ironic because i JUST finished replacing my oil pump on my E30 M3 and did the little drill trick on the nut with a wire tied to the sprocket.

[edlvrt]

In my non expert opinion, I am not worried about the very occasional trip I take above 6000 in 1st or 2nd gears. I don't spend much time up there at all as the overall wear and tear does not warrant the slight increase in acceleration. In 3rd gear and higher, I shift below 6000. The only time my car would experience 6000 RPM in 3rd, 4th, or 5th gears would be on a closed circuit track with a professional driver and what not:shifty


....
Have any of you...

1) Verified the ZHP oil pump nut already has threadlocker on it?


I'll need to search for it, but I have seen images of the regular M54B30 oil pump nut and the ZHP's (they have different BMW part numbers). The ZHP's had what appeared to be a nyloc threaded insert. I don't know if there is also a liquid thread lock applied as well.

EDIT Here is a link to e46f that shows the two nuts side by side. http://forum.e46fanatics.com/showthread.php?t=714263

Has anyone here, perhaps an engineer, seen any scientific tests that report the force required to remove a plain nut, a nut with liquid thread lock, and a nut with a nyloc insert?

The fact that BMW went to the trouble to put a different nut on the oil pump for a select few (but not special) cars does make me nervous. This is essentially proof that BMW recognized the potential issue and took the trouble to implement a solution. Another thing I don't understand is why the S54 does not suffer these harmonic vibrations. I would imagine that it has a longer crankshaft, as the cylinders are larger in diameter, and the longer piston stroke would require a longer lever arm on the crank pin. Though I think the S54 has an iron block for what it's worth.

[kayger12]

From everything I've read on this topic, the only people who need to be concerned enough to look into making a modification/improvement are those who track their ZHPs .

The rest of us have very little to worry about.

Droid X. Tapatalk. Use it.

[Hornung418]

From everything I've read on this topic, the only people who need to be concerned enough to look into making a modification/improvement are those who track their ZHPs .

The rest of us have very little to worry about.

Droid X. Tapatalk. Use it.

LNC tracks and autocrosses his ZHP.

Courtesy of Gingerbread...

[Hornung418]

Another thing I don't understand is why the S54 does not suffer these harmonic vibrations. I would imagine that it has a longer crankshaft, as the cylinders are larger in diameter, and the longer piston stroke would require a longer lever arm on the crank pin. Though I think the S54 has an iron block for what it's worth.
Iron absorbs vibrations better. This is why the M50/52 and S5X engines don't have this issue.


Courtesy of Gingerbread...

[LivesNearCostco]

Thanks, everyone. I enjoyed that e46Fanatics photo comparison! I don't think I've heard of this happening to a ZHP, but I started a thread on E46fanatics about getting faster 80-100mph acceleration on track and Rob43 (who tracks his 330) told me to secure the OPN because he blew a 330 M54 engine due to the OPN coming off.

I do a little track and AutoX, 5 track days so far this year and 2 more planned. In track, since I'm not competing, it's easy to just shift at 6000RPM. It's not like I'm gonna catch the E46/E92 M3s on the straights with more RPMs! (Rob43 apparently does TT, so he is competing.) But in AutoX I am competing and it's often easier to redline in 2nd gear at 65mph rather than upshift to 3rd. So I worry more about OPN during AutoX, worry more about moneyshift or rolling the car during track.

Kind of weird that I worry more about hurting the car than hurting myself at track days! Maybe it's because I've only driven tracks that have lots of runoff room and few walls. Or maybe I'm just in denial about my mortality! Sometimes I buy track-weekend insurance, which would cover the car if I crashed it (or someone hits me) at the track, but does not cover mechanical failures or blown engines.

Here's a CCA track day from September, AutoClub Speedway infield only (no oval). Actually this track has lots of walls but also lots of runoff room for the short straights and speeds we're going, or at least the speeds I'm going--the Corvette and 1M in our group were significantly faster!
http://www.youtube.com/watch?v=YTRBkvOa0aA

[kayger12]

LNC tracks and autocrosses his ZHP.

Courtesy of Gingerbread...

Ahh-- roger. I'd personally go with one of the mods then.

[az3579]

Iron absorbs vibrations better. This is why the M50/52 and S5X engines don't have this issue.


Courtesy of Gingerbread...

During my hordes of research on the S50 swap for my E30, I came across numerous suggestions from people to do the same mod to the nut on S50 engines as well. I don't think those are exempt either; perhaps even moreso relevant to those. The guy who did my swap explicitly told me that he was going to do that mod to the nut to make sure it doesn't come loose.



Dane,
Where was it verified that ZHPs came with the better nut? Is this nut supposed to completely prevent this issue from happening, or does it only reduce the chances?

Me needs to know before I do any more track/auto-x days...

[danewilson77]

During my hordes of research on the S50 swap for my E30, I came across numerous suggestions from people to do the same mod to the nut on S50 engines as well. I don't think those are exempt either; perhaps even moreso relevant to those. The guy who did my swap explicitly told me that he was going to do that mod to the nut to make sure it doesn't come loose.



Dane,
Where was it verified that ZHPs came with the better nut? Is this nut supposed to completely prevent this issue from happening, or does it only reduce the chances?

Me needs to know before I do any more track/auto-x days...

It's verified. The nut isn't coming off on our cars.

Read part #11 for the performance package.

http://www.realoem.com/bmw/showparts.do?model=EV53&mospid=47725&btnr=11_2868&hg=11&fg=30

http://i1015.photobucket.com/albums/af278/nicee46/Maintenance%20and%20Misc/69.png

Here is a picture of the ZHP M54 nut on the left and the standard M54 nut on the right:

http://i1015.photobucket.com/albums/af278/nicee46/Maintenance%20and%20Misc/1-2.jpg

Standard M54 Nut

http://i1015.photobucket.com/albums/af278/nicee46/Maintenance%20and%20Misc/2.jpg

ZHP Nut

http://i1015.photobucket.com/albums/af278/nicee46/Maintenance%20and%20Misc/3.jpg

***The material in the ZHP Nut is the same material that BMW applies to brand new flywheel bolts. They call them micro-encapsulated bolts. The reason why it is applied, is because BMW (or pretty much any other manufacturer) can control the application of threadlocker (and control quality) instead of relying on the assembly line worker.

[az3579]

Fantastic. Thanks DW; we can drive easy now.

[danewilson77]

Post #11 might be a nice addition to the ZHP FAQ. What do you think?

[kayger12]

Don't want to rain on any parades, but iirc, there have been cases of tracked ZHPs losing the nut despite the special liner.

I'll do some digging.

Droid X. Tapatalk. Use it.

[kayger12]

This from Bimmerfest:
"This is one of the weakness of the M54 engine. At high RPM, the harmonics will cause the oil pump nut to back off.
On the ZHP model, the oil pump nut has a loctite-like coating on the thread to reduce the likelihood of it coming loose. However, it still comes loose if the engine spends significant amount of time at high RPM."

Still digging for an actual confirmed case on a ZHP.

[Hornung418]

IDK why red thread-locker isn't on there. If you have to service your oil pump, just shear the nut off and just get a new bolt and put on the red thread-locker.

[az3579]

This from Bimmerfest:
"This is one of the weakness of the M54 engine. At high RPM, the harmonics will cause the oil pump nut to back off.
On the ZHP model, the oil pump nut has a loctite-like coating on the thread to reduce the likelihood of it coming loose. However, it still comes loose if the engine spends significant amount of time at high RPM."

Still digging for an actual confirmed case on a ZHP.


Question is, what is considered a significant amount of time... a few seconds? A minute? Milliseconds???
Did they specify?

[Hornung418]

BP, it's more like when you hold in gear while taking a corner. Do the same pattern every time round the track you will surely spin the nut off over a span of track days. But if you're going to track your car, it's always best to drop the Oil Pan and tighten that SOB down before each race.

[danewilson77]

But if you're going to track your car, it's always best to drop the Oil Pan and tighten that SOB down before each race.

Ha!

[LivesNearCostco]

The safety wire or tack-weld method guarantees the nut cannot back off, but if you say that to the hard-core E46fanatics crowd, they will point out that in some cases the oil pump sprocket shaft can shear off!

For now I will try not to spend more than a few seconds at a time over 6000 RPM. There are so many other ways I can improve my track driving that straight speed doesn't matter so much (except it's fun!). I probably only go to one track that has a big enough turn that might require sustained RPM's >6,000. The next time I run there, I'll try shifting to 5th because at my HPDE level, nobody is supposed to pass in those turns.

[az3579]

BP, it's more like when you hold in gear while taking a corner. Do the same pattern every time round the track you will surely spin the nut off over a span of track days.

That is a big problem then... at my local track, there are numerous occasions where I reach over 6000 RPM (I have 1,000 extra rpm to play with) and wouldn't make any sense for me to upshift, though thankfully those instances are not in the middle of a corner. Auto-x is not that big of a deal, because by the time I reach 6000RPM, I'd be doing nearly 60mph, which is far too fast for the course I usually run on. But the track... not a good place to lose that nut.



But if you're going to track your car, it's always best to drop the Oil Pan and tighten that SOB down before each race.

Seriously?? That's a lot of work just to tighten a nut... :(

[Hornung418]

That is a big problem then... at my local track, there are numerous occasions where I reach over 6000 RPM (I have 1,000 extra rpm to play with) and wouldn't make any sense for me to upshift, though thankfully those instances are not in the middle of a corner. Auto-x is not that big of a deal, because by the time I reach 6000RPM, I'd be doing nearly 60mph, which is far too fast for the course I usually run on. But the track... not a good place to lose that nut.


Seriously?? That's a lot of work just to tighten a nut... :(
That was a sarcastic reply.

[danewilson77]

That was a sarcastic reply.

Hehe....awesome.

[kayger12]

That was a sarcastic reply.

I-heart Horney Wit. :wub

Droid X. Tapatalk. Use it.

[az3579]

:rolleyes

:biggrin

[Whitexi]

So then if this is an issue with the M54B30 in the regular 330 what kinda nut does the M54B25 have? I gogled the issue with the 330 engine and found info, I googled it with the 325 engine and found nada.

[danewilson77]

So then if this is an issue with the M54B30 in the regular 330 what kinda nut does the M54B25 have? I gogled the issue with the 330 engine and found info, I googled it with the 325 engine and found nada.

Check out what pump nut is listed over at realoem... Then plug the p/n into ecs. You might get lucky with a pic.

HTC Thunderbolt+TT

[edlvrt]

From what I understand, the issue is more prevalent with the M54B30 (330i engine) because it has a longer stroke than the M54B25 (325i) with the same bore. As a result, the B30 has an undesired vibration at high RPMs. I'm no engineer, but it makes sense that the longer stroke=higher piston speed at RPM=more force placed on the crankshaft (assuming the pistons/conrods weigh the same) which somehow equals bad vibrations.

[Whitexi]

From what I understand, the issue is more prevalent with the M54B30 (330i engine) because it has a longer stroke than the M54B25 (325i) with the same bore. As a result, the B30 has an undesired vibration at high RPMs. I'm no engineer, but it makes sense that the longer stroke=higher piston speed at RPM=more force placed on the crankshaft (assuming the pistons/conrods weigh the same) which somehow equals bad vibrations.

Makes sense.

I looked it up and the M54B25 and M54B30 both have the same hex nut. I just never heard of this before, but it does seem to be a 330 issue. I searched for it under the 325 and nothing really about this that I could find, look for it under a 330 and theres a load of threads started with people with 330's that have had this issue. Seemed to be mostly tracked cars.

[LivesNearCostco]

Which is what I was doing Sunday, tracking the car. But when you can see the tach, you can see me upshifting right around 6,000 RPM each time, just trying to protect my baby! If I shift at redline I might get around the track a little faster, but since live timing is not allowed in the CCA schools and I'm not competing for anything in the NASA or SpeedVentures events, saving a few seconds around the track doesn't get me anything but anxiety about the OPN and bragging rights.
Edit: Oooohhh, notice in the video preview pic the temp needle is right in the middle at 12 o'clock, right where it should be. I checked that temp gauge a few times on the front and back straights.


http://www.youtube.com/watch?v=NAih1UuK3pI

[Hornung418]

You have got to invest in an external mic! Man I can't hear anything but wind!

[LivesNearCostco]

Too true. Unfortunately that Flip camera does not include an external mic option. Normally if the instructor and I yell at each other you can hear the words in the video, but he had a communicator so we were talking in normal voices.

[zj96sc]

Welding is a pretty sledgehammer approach to the problem. In the end of the day the only 100% guarantee is safety wire, which is why you see it all over real racing and aerospace applications. Might be able to talk Stage 8 into building something for the application if we showed enough interest.

If you've really got the OPN on your mind in the midst of a track session I'd recommend you pull the pan and get it safetywired. Your mind should be on the situation at hand and you should trust your machine 100% to the limits it was built for.

Completely losing the oil pump shaft is a different category of failure IMO and almost not even worth discussing. If that goes and takes your motor with it, it just wasn't your day.

[az3579]

Welding is a pretty sledgehammer approach to the problem. In the end of the day the only 100% guarantee is safety wire, which is why you see it all over real racing and aerospace applications. Might be able to talk Stage 8 into building something for the application if we showed enough interest.

If you've really got the OPN on your mind in the midst of a track session I'd recommend you pull the pan and get it safetywired. Your mind should be on the situation at hand and you should trust your machine 100% to the limits it was built for.

Completely losing the oil pump shaft is a different category of failure IMO and almost not even worth discussing. If that goes and takes your motor with it, it just wasn't your day.

I have to agree with this.


Sent from my iPhone 4S with Tapatalk

[zhp43867]

Welding is a pretty sledgehammer approach to the problem. In the end of the day the only 100% guarantee is safety wire, which is why you see it all over real racing and aerospace applications. Might be able to talk Stage 8 into building something for the application if we showed enough interest.

If you've really got the OPN on your mind in the midst of a track session I'd recommend you pull the pan and get it safetywired. Your mind should be on the situation at hand and you should trust your machine 100% to the limits it was built for.

Completely losing the oil pump shaft is a different category of failure IMO and almost not even worth discussing. If that goes and takes your motor with it, it just wasn't your day.

Welding and the safety wire are the two "fixes" which can provoke the oil pump shaft to shear. The real fix is the vaio oil pump, which runs around $750.

[Hornung418]

Got a link to that one?

[zj96sc]

Welding I'd buy given that it might alter the heat treat of the shaft. How would safety wire lead to shearing of the shaft?

[LivesNearCostco]

Maybe unbalances the sprocket if you only put the wire on one side? I guess you could drill the nut on two sides and use two pieces of wire. Or maybe because once it's safety wired or tack welded, the driver feels more confident to ride the rev limiter all the time?

[zhp43867]

Maybe unbalances the sprocket if you only put the wire on one side? I guess you could drill the nut on two sides and use two pieces of wire. Or maybe because once it's safety wired or tack welded, the driver feels more confident to ride the rev limiter all the time?

Bingo. It has to do with imbalance caused by the weld and the safety wire I believe. All of this information is on E46fanatics in the oil pump thread here. (http://forum.e46fanatics.com/showthread.php?t=833891)