[E90lova]

Originally Posted by TrackEnthusiast

Your car is x-drive, right? I've seen the oil pan of xdive cars and their different and, much likely, smaller capacity than the RWD cars because of the space the front axels take.

Yes that's right it is Xdrive. There is a member that tracks his F30 Xdrive as well many track days with no failure.

[AbbeyRoad]

My N55 xDrive locked up on the highway. 140k miles, daily driver. About to pull the engine in my driveway. It seems to almost turn over but very sticky and won't start. Almost definitely a rod bearing, I would say.

Aside from premium bearings and Arp rod bolts, I want to put an S55 oil pump in. Since the S55 aux pump and pickup won't fit, I would use the S55 oil pump alone and stock oil pickup. S55 oil pumps are supposed to have higher flow - is this true?

Is this all a good idea?

From the discussion above it doesn't seem like xDrive has any aftermarket options.

[If in Doubt_Flat Out]

Originally Posted by AbbeyRoad

My N55 xDrive locked up on the highway. 140k miles, daily driver. About to pull the engine in my driveway. It seems to almost turn over but very sticky and won't start. Almost definitely a rod bearing, I would say.

Aside from premium bearings and Arp rod bolts, I want to put an S55 oil pump in. Since the S55 aux pump and pickup won't fit, I would use the S55 oil pump alone and stock oil pickup. S55 oil pumps are supposed to have higher flow - is this true?

Is this all a good idea?

From the discussion above it doesn't seem like xDrive has any aftermarket options.

Hi, there,

There is currently no solution for retrofitting the S55 secondary oil pump to an Xdrive model.

I found a dealer in Europe who offers a baffle for Xdrive but I did not buy it to test:
https://revmatch.eu/product/oil-sump...or-n55-xdrive/

As for me, I have a EWG 335i xdrive mperf and I'm thinking of swapping an s55 engine but keeping the xdrive oil sump (I bought the car at such a low price that it would be a shame to leave it in its normal condition.).

I'd say because of the S55's improved cooling system and stronger internal components, but also to have a car that stands out from the crowd and to take it on the racetrack, while keeping the ZF8hp gearbox with stage 3 XHP, which allows it to shimmy very quickly, but remain comfortable in town..

By the way, if anyone can advise me on how to get the S55's water pumps to work on the F30, since these two cars share the same DME, should I make the F30 think it's an F80?
Are there any hardware modifications required?

Here's an example of my goal:

If you have any technical advice, please don't hesitate to contact me.

Have a nice day

[AbbeyRoad]

Originally Posted by If in Doubt_Flat Out

Hi, there, There is currently no s......

Definitely a worthwhile project!

I have the ZF6 in my 2010 X5 and the ZF8 in the 2012 X5 and I will say there is a world of difference -- like driving a different car.

I am half way done pulling the engine. Everything up top is out of the engine bay. Now have to take apart the front right knuckle to get out the drive shaft.

I am researching if it works to jam the oil pump in "full-tilt" by replacing the pivot-return-springs with a solid spacer, or if you will get a "oil pressure too high" engine code. I can also put in a thicker spring on the oil pressure valve.

Another solution is to put in a small resister at the oil pressure sensor. This will make the engine software think the oil pressure is lower than it really is and raise it a bit more than stock.

If anyone knows if these ideas are workable, please help!

[AbbeyRoad]

I worked on this 4 hours yesterday and 3 hours today. People say it takes 5 hours total to remove a xDrive N55 --- ain't no way!

Almost ready to attach the hoist.

Pic in case anyone is interested. It ain't off topic I guess.

[If in Doubt_Flat Out]

Originally Posted by AbbeyRoad

Definitely a worthwhile project!

I have the ZF6 in my 2010 X5 and the ZF8 in the 2012 X5 and I will say there is a world of difference -- like driving a different car.

I am half way done pulling the engine. Everything up top is out of the engine bay. Now have to take apart the front right knuckle to get out the drive shaft.

I am researching if it works to jam the oil pump in "full-tilt" by replacing the pivot-return-springs with a solid spacer, or if you will get a "oil pressure too high" engine code. I can also put in a thicker spring on the oil pressure valve.

Another solution is to put in a small resister at the oil pressure sensor. This will make the engine software think the oil pressure is lower than it really is and raise it a bit more than stock.

If anyone knows if these ideas are workable, please help!

Hi there,

I think that the oil sump of the X-drive models are a bit smaller in terms of capacity than a classic RWD, this could cause the oil to overflow at the OFHG.

Otherwise, I've seen this solution on youtube which apparently allows you to add a little more oil without touching the oil pump:

https://youtu.be/Zt2jQgL18II?feature=shared

Let me know what you think

[AbbeyRoad]

Originally Posted by If in Doubt_Flat Out

Hi th.....

Seems like a popular solution.

Worked 2 hours on sat and another 3 today. Not an easy job.....



Here are I think rods 3 and 4. One has overheated:



Here are two bearing. Both toast - even the one that did not overheat. 3 spun bearings total!!! How did this happen ?!?!!?!? Anyone? Valve train is good, BTW.

[AbbeyRoad]

^^^ seriously this is crazy.

BTW my oil was half way between min and max. Could that have caused this?

[If in Doubt_Flat Out]

Originally Posted by AbbeyRoad

^^^ seriously this is crazy.

BTW my oil was half way between min and max. Could that have caused this?

Hi, there,
The viscosity of the oil plays a big part in preventing friction between mechanical parts, plus if the oil level is low and you accelerate it will increase the chances of friction, yours are cooked 🤣
We changed mine for oem ones with a wbc coating (214,000km ~ 121,000 miles) and they had linear wear check the photos.

To prevent this as much as possible, I leave the car idle for 3 minutes, never accelerate when cold and when I'm planning a day where I'm going to push the pedal to the metal (accelerate hard) I check the oil level and add a little extra.

[Polo08816]

Originally Posted by AbbeyRoad

Seems like a popular solution.

Worked 2 hours on sat and another 3 today. Not an easy job.....

Attachment 3612913

Here are I think rods 3 and 4. One has overheated:

Attachment 3612915

Here are two bearing. Both toast - even the one that did not overheat. 3 spun bearings total!!! How did this happen ?!?!!?!? Anyone? Valve train is good, BTW.

Attachment 3612916

Originally Posted by AbbeyRoad

^^^ seriously this is crazy.

BTW my oil was half way between min and max. Could that have caused this?

This is most likely a failed oil pump if you have more than 1 cylinder that has spun bearings. More than 1 cylinder would experience higher oil temperature under this condition.

[AbbeyRoad]

Originally Posted by Polo08816

This is most likely a failed oil pump if you have more than 1 cylinder that has spun bearings. More than 1 cylinder would experience higher oil temperature under this condition.

Good idea. I took it apart. It doesnt look bad.

But I think I have a theory on the problem: the engine computer cannot raise the oil pressure fast enough when you hit the gas hard. This is because of the feedback loop between the oil pump, oil sensor, oil solenoid, and oil pump internal pivot action. I WILL ABSOLUTELY BET that when you hit the gas hard from cruising that the crank turns a dozen times before the oil pressure builds. It is in those few milliseconds that the bearings dry out. And I will bet it gets worse as the engine ages.

Simple solution: jam the pivot at 100%. Let it pump oil like a Chevy.

The "oil pressure too high" engine code does not cause a check engine light nor an OBD fail. I looked it up just now.

[AbbeyRoad]

So I made this video explaining the problem in full. I spent a lot of time thinking about this, and it may be the first proper solution to the N55 rod bearing problem.

I think I am actually going to try this....

[If in Doubt_Flat Out]

Originally Posted by AbbeyRoad

So I made this video explaining the problem in full. I spent a lot of time thinking about this, and it may be the first proper solution to the N55 rod bearing problem.

I think I am actually going to try this....

Hi there,
Awesome video very well explained.
In fact, the spun bearings are only symptoms of the disease (oil pressure too low).
Do you think it would be possible to record the oil pressure sent to the engine components in different scenarios, correlate the datas and use it to remap the car's computer and ask it to send more pressure than originally planned depending on the engine rpms ?

Turning the valve to increase pressure also seems a good idea, but the problem will be the pump's resistance to use in the sense of how it will react in the long term if it's forced to send maximum pressure regardless of engine speed (only a test in real life can tell).

Do you think the S55 pump will fit with the N55 Xdrive oil pan?

I had seen a video about the E63s AMG M157 engine which also had oil pressure irregularity problems due to a sensor:

https://www.youtube.com/watch?v=MuZJSGN8qZ4

Anyway, thanks for the video and the effort to understand the lubrication system.

[AbbeyRoad]

Originally Posted by If in Doubt_Flat Out

Hi ther.....

Remap is possible. I already asked Twisted Tuning: Search for "Increasing Oil Pressure on N55 preliminary testing April 25 2018" on ***********. No response from Twisted Tuning just yet. Please message them too.

To log properly, you need to get the pressure just before the rod journal. It's a big project. You also need to pick up even 1 millisecond of low pressure. OBD logging won't see that. Mech. Eng. labs in postgrad do these kinds of experiments.

I think long term the pump will be fine at 100% flow rate. When hot and at low rpm the pressure is moderate. That's where you do most of your driving.

For this, S55 and N55 pumps are identical on the outside AFAIK. A used S55 pump for me arrives in a week. So we'll know.

Disconnecting the solenoid on the N55 is a good idea. But the problem may also be caused by the pump's mechanical reaction time.

[If in Doubt_Flat Out]

Originally Posted by AbbeyRoad

Remap is possible. I already asked Twisted Tuning: Search for "Increasing Oil Pressure on N55 preliminary testing April 25 2018" on ***********. No response from Twisted Tuning just yet. Please message them too.

To log properly, you need to get the pressure just before the rod journal. It's a big project. You also need to pick up even 1 millisecond of low pressure. OBD logging won't see that. Mech. Eng. labs in postgrad do these kinds of experiments.

I think long term the pump will be fine at 100% flow rate. When hot and at low rpm the pressure is moderate. That's where you do most of your driving.

For this, S55 and N55 pumps are identical on the outside AFAIK. A used S55 pump for me arrives in a week. So we'll know.

Disconnecting the solenoid on the N55 is a good idea. But the problem may also be caused by the pump's mechanical reaction time.

Yes, I'm going to send him a message too, because it would be great to have expoitable data that could allow a new map to be injected.

I have a question if I swap an S55 in place of my N55 EWG, I know that if I want to keep the xdrive I replace the oil pan of the S55 by the one of the N55 and I remove the secondary oil pump, but I could use your technique to increase the pressure of the oil pump of the S55.

However, how do I get the cooling system (several water pumps) and the fueling system (double pumps) to work?

Should I use a standalone system, or can I inject an S55 map into my DME because these two models share the same DME?
Are there any hardware modifications to enable the systems to run as close to the OEM as possible?

KR

[AbbeyRoad]

Originally Posted by If in Doubt_Flat Out

Yes, I'm g.....

I only worked on my own fleet. N52 and N55. Others were Jeep and Dodge.

[Polo08816]

Originally Posted by If in Doubt_Flat Out

Hi there,
Awesome video very well explained.
In fact, the spun bearings are only symptoms of the disease (oil pressure too low).
Do you think it would be possible to record the oil pressure sent to the engine components in different scenarios, correlate the datas and use it to remap the car's computer and ask it to send more pressure than originally planned depending on the engine rpms ?

Turning the valve to increase pressure also seems a good idea, but the problem will be the pump's resistance to use in the sense of how it will react in the long term if it's forced to send maximum pressure regardless of engine speed (only a test in real life can tell).

Do you think the S55 pump will fit with the N55 Xdrive oil pan?

I had seen a video about the E63s AMG M157 engine which also had oil pressure irregularity problems due to a sensor:

Anyway, thanks for the video and the effort to understand the lubrication system.

I don't think the problem is normal operating oil pressure per say.

Usually the plastic tray fails after time (heat cycles) and the pump is unable to scavenge oil from the pickup tube.

The S55 system's purpose is simply to maintain oil pressure under more extreme conditions than what the normal non M2 N55 oil sump system would typically face.

I think trying to increase the normal operating oil pressure is a modification in search of a problem that really doesn't exist.

[AbbeyRoad]

Originally Posted by Polo08816

I don't th.....

Good idea. So I inspected my plastic tray more carefully and it looks perfect. That definitely isn't the problem.

[AbbeyRoad]

Updates:

The S55 oil pump arrived and I measured the internals: the springs are identical in length and wire. The diameters of the drive wheels are all identical, and the depth of the volumes are identical. The drive sprocket is identical. The entry and exit holes are identical.

The only difference is the extra mechanical drive to the S55 aux pump.

In other words, the claimed "18% increase oil flow" in the S55 tech doc must be by electronic control alone.

So, if one is going with my experiment in the video, then flipping the piston is all one needs to do.

Other updates:

Using this video below (not my video) I straightened my crank. Since three journals had overheated this was very difficult and time-consuming, but it is now straight to within 0.02mm. I plan on sending it to be reground 0.25 under.

I got 4 good rods on ebay from a nuked N55. So I have more than 6 good rods in total.

I poured alcohol in my ports - 1 intake and 1 exhaust port have a small leak and need to be lapped... getting a $20 lapping kit on Amazon.

My notes:

1. Hastings Piston Rings 2N5230 - summitracing has them.
2. https://help.fcpeuro.com/hc/en-us/ar...-Bearing-codes

[AmuroRay]

Originally Posted by AbbeyRoad

Updates:

The S55 oil pump arrived and I measured the internals: the springs are identical in length and wire. The diameters of the drive wheels are all identical, and the depth of the volumes are identical. The drive sprocket is identical. The entry and exit holes are identical.

The only difference is the extra mechanical drive to the S55 aux pump.

In other words, the claimed "18% increase oil flow" in the S55 tech doc must be by electronic control alone.

So, if one is going with my experiment in the video, then flipping the piston is all one needs to do.

Other updates:

Using this video below I straightened my crank. Since three journals had overheated this was very difficult and time-consuming, but it is now straight to within 0.02mm. I plan on sending it to be reground 0.25 under.

I got 4 good rods on ebay from a nuked N55. So I have more than 6 good rods in total.

I poured alcohol in my ports - 1 intake and 1 exhaust port have a small leak and need to be lapped... getting a $20 lapping kit on Amazon.

First - Awesome work in rebuilding the engine. Second, what does he bold part mean?

[AbbeyRoad]

Originally Posted by AmuroRay

....what does he bold part mean?

Thanks!

See the video from above, "So I made this video explaining the problem in full." Flipping the piston at 11m15s in the video.

[AbbeyRoad]

Ok, I have another bombshell video explaining how the N55/S55/N54 oil pump is able to pump UNFILTERED OIL into your oil rail: