E46 Fanatics Forum banner
Status
Not open for further replies.

M54 Oil Pump solution

214K views 343 replies 80 participants last post by  Mark II 
#1 ·
After years of hearing about this oil pump solution for the M54, I finally ordered one to try on my 330i street car.

What is the problem with the M54 oil pump? The M54, and more notoriously the M54B30, seems to vibrate the oil pump nut off when rev'd above 6000 RPM. The more time you spend over 6k, the sooner the oil pump nut seems to come loose, which is followed by the oil pump sprocket coming off, which causes a total loss of oil pressure. (By by engine)

Here's a view of a stock oil pump without the sprocket installed:



What's inside:




The most common solution seems to be to weld the oil pump nut (OPN) on to keep it from vibrating off....even tough the nut is a reverse thread. While this works in the short term, eventually the shaft that the sprocket and nut have been welded to fails, (It literally shears off where it holds the sprocket) and the engine looses oil pressure. Here is an example of how this welding is done:



And the back side of the sprocket:




Another solution that many try is from VAC Motorsports for $200. They offer a kit with a new sprocket and oil pump shaft that must be pressed into the existing oil pump housing. Here's the kit:





Here the VAC Motorsports shaft has been pressed into the oil pump housing:



And all buttoned up:



Note that the bolt is a reverse threaded, and was installed to VAC's specified torque, and additionally we added Loctite Red to the threads.

I would love to report that this simple solution works, but it didn't in my engine. When the engine was torn down after approximately 80hrs or run time, I found the bolt loose to the touch, and the sprocket somewhat wobbly on the shaft. Based on what I found, I would say that it was just a matter of time on my engine before the oil pump drive sprocket came off. I have also heard from numberous other people that have installed this kit, on M54s, M52s, and S52s, and have had oil pump failures. It may allow the oil pump to last a little bit longer than the OEM piece, but eventually it fails.

So this left 2 solutions:

  1. Install the BMW Motorsport oil pump system for M54s at a cost of $3000
  2. Install a dry sump system at a cost of well over $6000 to do it correctly

Most people at seeing these prices seem to get the VAC kit and hope for the best. For me, this just isn't an option I would be comfortable with.

I decided to try a solution that Greg Smith ran on his car, and isn't commercially available, but if you ask nice he can source one for you. The price is more than the VAC Motorsports solution, but much less than the BMW Motorsports solution. What you get is a completely new OEM oil pump housing and internals, with a specially machined drive shaft and sprocket. I would say most of the cost is in starting with a brand new oil pump core, but I'm not complaining. This is one very nicely put together oil pump package:











Taking the sprocket off, we can see what makes this solution so special:







Yes, that's all one solid machined piece that the sprocket bolts to:




From a piece of mind perspective, I think this solution is a bargain.
 
See less See more
17
#12 · (Edited)
I presume the lock-tite nuts on the later cars are still very much prone to this problem?
The two things the later cars have going for them:
  • a different P/N vibration damper that lists a slightly wider range of harmonic damping frequencies - I posted pics in some thread around here in response to azzy's question about it
  • a sprocket nut (aka OPN) with factory applied loctite
Do they make a difference? Although I can't recall a post about a newer car (IIRC 9/2003 onward) losing its sprocket, I doubt it. I think it's just a matter of time- tracktime that is. Really hanging out above the 6K mark is going to create wild crankshaft harmonics that will eventually loosen the nut or break the sprocket shaft. These are street cars and I guess BMW doesn't expect revving like that. When the harmonics get going your crankshaft starts to become much less a solid piece of forged steel and much more a really long tuning fork. Especially if you're making more power than stock and/or running a lightweight flywheel. The oil pump sprocket is chained to the crankshaft and gets abused by the thrashing harmonics. To address this nonsense I installed Greg's upgraded pump, an ATI Super Damper and stuck with the stock DMF when I replaced my clutch. The perceptible upshot is that now when I rev over 6K it's completely butter smooth (this is pretty much due to the Super Damper). Before, it was kind of angry-feeling. The more imperceptible upshot is total peace of mind about tracking it.

One simpler alternative might be replacing the stock vibration damper at a conservative interval - TxZHP04 did this and said it felt a lot smoother. I think older cars tend to see more OPN trouble primarily because their vibration dampers wear out and usually go unreplaced for years. The problem is that, like a bushing, they can look ok but not work well. Whatever the car's year, they're made of rubber and ~5 years is a reasonable street driving lifespan for them IMO. Infamous racer mrshelley replaces his vibration damper(s) after every 1-2 GA events(!). The more robust and better damping ATI Super Damper is rated for something like 5-10 years depending on how much track you're doing, but it's not allowed in some racing classes.

Can you get by tracking the car without the upgraded pump if your harmonic damping is good enough? Maybe. Time will tell. But if you're really hanging out above 6K regularly I wouldn't risk it myself.

Fwiw my OPN was on super tight after about 75K of spirited street driving including about 3K miles turboed. Did I rev above 6K much? Sure. Did I hang out there much? No.

The biggest pain is the that you have to drop the front subframe: Disconnect steering shaft and hydraulic lines, disconnect the brakes, and drop the struts. You'll have to have an engine support from the top, as you'll be dropping the engine mounts as well. Pulling the pan and pump in comparison is pretty easy.
When I did it I didn't disconnect any hydraulic or brake lines or drop the struts. To get the subframe out I popped the control arm connections out of the wheel hubs, moved the steering rack forward, undid the lower motor mount nuts, undid the subframe bolts and voila. This was all per BMW TIS. Not easy at all either. And I wouldn't trust an engine hoist if you're leaving it over night- I used a screw jack under each motor mount to be safe.
 
#15 ·
The harmonics is the real issue and only for the 3.0l motor. You can take the 2.8 or 2.5 and just safety wire the nut and you'll be set for what most people do.

I grenaded a motor this year just because it is seeing 6700 on the high banks of Daytona and 6900 when it runs in a draft. This is for at least 10 seconds per lap. After enough laps, the crank broke, the timing wheel exploded, the guide rail on the oil pump chain was broken and the oil pump chain shot all of the rollers out of it. On top of all of that, the harmonic balancer had rotated by about 60 degrees (the timing mark was that far off). In the series I run in, I'm limited by rpm is I like it or not. The N52 motors do not suffer from this problem.

This is the most extreme situation and I doubt any of you will ever see this. What usually happens, is the oil pump shaft shears off and the motor blows up (they can run for around 117 seconds without oil pressure).

I would suggest this oil pump shaft if you are going to do some racing with the car. As these cars get older and cheaper, people will start to track them. Thing is, what I learned 10 years ago, is finally coming around for everyone else.

If you are going to run occasional track days with a regular 330, then you are fine. If you are going to put some serious time on it (5 to 6 hours per weekend) then you might want to look at this option. Most people don't run their car on the track flat out for long periods of time. If you do, just beware of what can happen.
 
#19 ·
I grenaded a motor this year just because it is seeing 6700 on the high banks of Daytona and 6900 when it runs in a draft. This is for at least 10 seconds per lap. After enough laps, the crank broke, the timing wheel exploded, the guide rail on the oil pump chain was broken and the oil pump chain shot all of the rollers out of it. On top of all of that, the harmonic balancer had rotated by about 60 degrees (the timing mark was that far off). In the series I run in, I'm limited by rpm is I like it or not.
Wow, I didn't realize it could break that bad. I'm hoping if this ever does happen the nut just shears or falls off and I can still save the engine. I'll be shifting at 6200 for the time being.
 
#18 · (Edited)
So the 2.5's are good? And why is this?
The M54B25 is oversquare so I guess something to do with its [cast construction, ]comparatively shallower crank bends and [perhaps] the resultant 'lower piston speed relative to engine speed' keep the harmonics from really going.

how about a 2.5 that has the 330 crank in it?
I'd say it's in the same boat as the 3.0 liter engine.

If you are going to run occasional track days with a regular 330, then you are fine. If you are going to put some serious time on it (5 to 6 hours per weekend) then you might want to look at this option. Most people don't run their car on the track flat out for long periods of time. If you do, just beware of what can happen.
Great guideline^
 
#20 ·
I was going to go with this solution but don't think I need it. I track the car for 4-6 weekends per year. With my s/c kit and the twinscrew's low end torque, I really don't need to hang above 6k rpm too much. In fact, I think my car does best between 3.5k rpm to 6k rpm.

I've concluded from past threads, the Greg Smith solution is the only way to go if you're going to go through the time and expense to do this.
 
#23 ·
New issue I just discovered. Good info in the thread. :thumbup:

I dont track the car, but Im pretty spirited in the street.

It seems hanging out around 6K for too long can cause this problem. I find myself often transient in this RPM range, but never for too long.

For someone who drives the car fairly hard in the street, (car is stock no SC or anything), at what mileage might I expect possible oil pump failure - how long do these oil pumps last and is it wise to replace as preventive maintenance at some mileage milestone?
 
#31 ·
My 330 nut backed off and ruined the engine at 47,500 miles. I had done two, maybe three AutoXs and no track days with the car. Stock flywheel/clutch. Only power mods were a Dinan intake and exhaust.

Not common, but it can happen without track time. I liked to take the car to redline but don't remember hanging out there.

Tim
 
#32 ·
My 330 nut backed off and ruined the engine at 47,500 miles. I had done two, maybe three AutoXs and no track days with the car. Stock flywheel/clutch. Only power mods were a Dinan intake and exhaust.

Not common, but it can happen without track time. I liked to take the car to redline but don't remember hanging out there.

Tim

This is the type of story Im worried about.

I push this car really really hard at times and would not mind having the oil pump replaced preemptively.


Is it possible to determine whether the nut is close to being compromised?


Has anyone else had to have their oil pump replaced?

Is losing the oil pump GAME OVER, or if I shut down in time will I able to salvage it.

Yikes.
 
#35 ·
I got to visit Metric Mechanic 3 years ago. I asked them about this oil pump nut issue. They were not aware of the bad harmonics issue but mentioned that the nut will come right off if you spin the engine backwards. MM said this every BMW engine is like this.

But I would 100% go with MrShelley's assessment...how can you not trust a guy who can tell you how long your engine will run without oil:rofl:
 
#37 ·
OrientBlau, i have the same issue except i get the yellow light but not necessarily after spirited driving.
i always check my oil in my ride as well as my truck since it(truck)has a bad rear main seal.
my oil light problem arose after an indy tech put royal purple in. dealer replaced oil sensor under cpo but the problem is back but not as bad as it was. i get the yellow only after i shut it down; before i was getting it while driving. only yellow, never red.
 
#38 ·
ok i read every post descriptively in this thread and all very good inforamtion.. i do very spirited driving and realize that at any given time the nut can wiggle itself loose and only down hill from there. my question is if the stock nut can come off at any time does the vac solution create a median between stock and the upgraded oil pump nut solution in this thread? would it give you better peace of mind than haveing the stock nut in?
please dont tell me mrshellys answer was the most diffinitive answer you can find because i can realize that..


lets say you did no spirited driving would the vac solution be a upgrade and make the nut more durable or last longer?
 
#39 ·
i do very spirited driving and realize that at any given time the nut can wiggle itself loose...
IMO: That's a big exaggeration^; stick with mrshelley's guideline. Tim's was an isolated incident (or maybe 01's are somehow extra vulnerable). I redlined my ZHP often and even after a few thousand miles turboed the nut was tight as hell. I was at around 80K when I replaced the pump. AggieE46's OPN wasn't going anywhere either when he checked.

does the vac solution create a median between stock and the upgraded oil pump nut solution in this thread? would it give you better peace of mind than haveing the stock nut in?
I wouldn't consider the VAC pump at all given that, despite the hype on the VAC site,:

I have also heard from numerous other people that have installed this kit, on M54s, M52s, and S52s, and have had oil pump failures. It may allow the oil pump to last a little bit longer than the OEM piece, but eventually it fails.
I'd say if you're putting in the not inconsiderable effort to get to the pump, you might as well do it right.
 
#47 ·
With a simple hand drill and a small drill bit, you can just drill out the stock nut (takes about 2 minutes). It's not some super hardened item. Also, if you do safety wire it, then go ahead and loctite it.

As for the valve retainers, it's a matter of time when someone will break one. I just broke one at Lime Rock and the last time that happened was in 2005. On the other hand, every engine rebuild I do, the car gets brand new retainers, springs and valves (the old ones go right in the garbage). I guess fate caught up with me. I know other teams that had plenty of failures but they were just reusing the old retainers. Since we have to run the stock stuff, I just change out the parts more often. Since the retainers are dirt cheap, it's cheap insurance (same for the springs and valves).

When we ran the Z3's with the 2.8l motor, we used to rev them to 7500. They broke retainers all of the time and GA let us run an aftermarket one. Then the problem was solved. With the 330, they put the kabosh on that.

My suggestion would be to change out the seals, valves, springs and retainers when you decide to pull the head for a rebuild. Also, the new valves are ready to use, no machining necessary.
 
#49 ·
As the pumps get older, the oil pressure bypass valve can become gummy with junk. I've seen this on some high mileage engines or ones that had a lack of oil changes. The valve is held in by a circlip and the whole pump can be disassembled then cleaned. If you have the pan off, it's worth it to remove the pump and clean it along with the pickup. Plus you might want to change the o-ring for the pickup.

Also, you can just bump up the weight of the oil in the summer and see if it takes cars of the problem.
 
#59 ·
A big thanks goes out to Greg for going out of his way to get me that missing pin! Pump is now installed and my leaking oil pan gasket has been replaced. Upon dropping the oil pan, one of the first things I did was check the condition of the oil pump nut. Even with my occasional run to the 7k rpm red line, the nut was still quite snug.
 
#60 ·
I will say this. While this solution is still the best i have come across so far. I decided that since a) I am poor, and b) I am not a professional racer, and my car remains street legal, I decided on locktite and a safety wire from BimmerWorld in the end. I am going to run this m50 hard,and eventually boost, Just hopeing this will not be a decision i live to regret. Although going through the swapping process (and realistically the engine rebuild process) for the first time, has really opened my eyes to the true cost, and amount of work that goes into this sort of stuff.
 
#62 ·
Is this an M54B30 specific issue? Or do other BMW engines (S54 for example) suffer from the same issue? If the S54 suffers from a similar problem, is there a similar solution? Since the S54 redlines at 8k, I'd be kinda concerned about the long-term reliability of the oil pump if there are similar harmonics prblems
 
Status
Not open for further replies.
You have insufficient privileges to reply here.
Top