[Nemo550]

Hello everyone,

I purchased a used 2013 550XI back in April of this year. After getting screwed by the first dealer, I am hesitant to take it back to a bmw dealer to diagnose this issue.

I have done roughly 12 hours of research on this forum, google, and YouTube. In my eyes that's not much research, and I feel I'd get farther asking for help.

The vehicle is in comfort setting, and the drivetrain is normal. (Not in sport or sequential manual.) With the parameters being specified. When the vehicle comes to a complete stop. After roughly one second the nose of the vehicle drops down. When what I take is the neutral idle control programming doing its job.

When this takes place there is a loud clunk then the nose of the car dips. The origin of this noise sounds like it comes from the transmission. When I release the brake to accelerate the clunk occurs again. Now I don't have experience with this drivetrain or any of the sequences that occur at a stop.

This problem still occurs when the vehicle is in Auto H. Although it doesn't occur when the vehicle's sport or sequential manual is activated. (Feels like the vehicle is ready for anything. Whereas in the comfort setting. It feels like the vehicle just got done running a race and fell to the ground.)

Any advice is greatly appreciated. These dealers won't let me talk to the technicians. Only service advisors, that seems like they lack the knowledge and are just middlemen.

[Ryan5034]

The nose moves down ever so slightly with the X5's as well. I don't get any clunking though.

[Nemo550]

Due to the lack of advice I've decided to take this into my own hands, and will keep everyone updated to help anyone in the future that might have this issue.

The "NIC" (Neutral idle control) gearbox feature uncouples the torque converter when the vehicle is stationary, and whenever the brakes are applied. This reduces the load on the engine to a minimum. Hence why the nose of the vehicle dips.

First I just wanted to have the dealership to disable the "NIC" function. After some thought I came to the conclusion, that it could be similar to putting a bandaid on a good ole Detroit stabbing.

I came up with a list to help diagnose the issue myself. Which is described below.

1.) Order NT510 from ECS Tuning. Check to see if there's any underlying codes before a drive and after a drive. Checking to see if there's anything wrong when the vehicle reaches operating temp or cold. After test see if a transmission adaptation reset resolves issue.
-If nothing found, and a transmission adaptation reset does not solve issue. Continue to step number two.

2.) Lift the vehicle, remove the skid plates, and check for worn "Universal flex disks". (Guibo) Correct me if I'm wrong, but X-drive should have two.
Also be sure to check the Universal joints, and any rubber transmission mounts.
-If in good or exceptional condition continue to step number three.
-If in less than good condition, replace. Drive and see if the issue is resolved. If not continue to step number three.

3.) While vehicle is lifted and skid plates removed. Check skid plates for leaked transmission fluid. Follow proper trans pan / filter, and trans fluid replacement procedures. Before the pan is replaced, remove the mechatronic unit and check seals. Replace the seals while everything is exposed. Put the mechatronic unit back where it belongs and torque to spec. Complete the trans pan and fluid procedure, and reset the transmission adaptations before driving on the road but after the vehicle is filled to spec with trans fluid. Check if problem is resolved.
-If issue isn't resolved, immediately light on fire and walk away. Lol just kidding, take it to the dealer, because you just replaced all the wear items not covered under warranty. Except for the Clutch.
-If issue is resolved then that's great!


If anyone has any input it would be greatly appreciated.
Once the issue is resolved I will see if the topic title can be changed to what was discovered.
Also this is my first bmw and I want to learn how to fix everything. It only has 40k miles on it.

[Surly73]

I can't offer a lot of technical help on the issue, but some observations.

I can clearly feel my '11 535xi releasing the TC. Often, my system seems to be confused - 1/ if I'm trying to creep forward there's lurching. It doesn't seem to be sure about keeping the TC engaged 2/ Sometimes the TC engagement isn't in sync with the gear change and there's a little lurch while accelerating because timing is off. Dealer master tech/foreman don't have much to say and even though it happens to me "a lot", it's next to impossible to properly demonstrate to a tech on demand. My car likes to work perfectly when a foreman is inside.

I have never, ever experienced this "after a second the nose dips". First, the tail of the car is probably rising, which feels like the same thing but it's the driveline being released from a loaded up state. I have talked with folks to have older AT BMWs with no NIC function, and have heard about TCs which were "overly engaged" and not giving enough slip when idling. I wonder if something similar is happening to you, making the NIC intervention way more noticeable and resulting in a noise. Assuming your engine is idling at the proper speed, the difference between TC engaged and disengaged is far greater on your vehicle than the average 8-speed ZF AT equipped BMW I've even driven.

The "clunk" may be a mount or flex disk that is shot, sure, but the rear of the vehicle shouldn't be popping up after a second at all in my experience. You may have multiple issues.

My dealer master techs have hinted to me that 1/ they don't do hardly any of the computer work at the dealers here in Canada anyways. They hook the cars up and people from BMWNA "remote in" and do everything 2/ they can pull extremely enhanced diagnostics from transmission and transfer case components. Clutch wear, fluid condition, every little thing it seems. This is different than a waiting malfunction code.

As much as you hate dealers, a dealer or true ZF transmission specialist might be able to zero right in on a problem. I, personally, wouldn't know who to trust to ensure that you're getting the expertise you require.

[Nemo550]

Thank you Slury, your input had helped. I was able to take my vehicle to the auto hobby shop on base and start digging into my car. Just enough to see that the flex disk is worn. I didn't have time to check the center support bearing but ordered one anyways.
What do you mean by TC?

Update:
Upon inspection, the rear flex disk is worn. As for the front flex disk. It seems to be an aluminum upgraded part. (Pictures will be posted below.) I didn't have enough time to check the center support bearing. Yet ordered one anyways. Probably going to replace it even if it's good. Due to the extra wear caused by the worn flex disks. The rear differential mounts are bad and will be replaced as well.

If people want me to make a DIY on the replacement of the parts for a F10 550XI I will do so. Which will be posted in the DIY section.

With the adaptation reset made the transmission feel brand new. Although it didn't help with the clunk. I still recorded the values hoping that it might help someone. Everyone's might be different, but you never know. I recorded these to see how much of a difference there was between new parts and worn parts on the drivetrain.
I have to drive to Colorado Sunday after the new parts are installed. To start a new contract. The adaptations will be reset, and the recording done after the same amount of miles traveled. They are be listed below.

Adaptation Values (Original asshole driving)

Clutch Fill Pressures Rapid Fill Times
A: -211 / 47mbar A: 2 / 45ms
B: -58 / 24mbar B: -15 / 24ms
C: 197 / 89mbar C: 10 / 89ms
D: 23 / 62mbar D: 5 / 61ms
E: 111 / 36mbar E: 10 / 35ms

Adaptation Values (Reset then 5hour drive, grandpa driving)

Clutch Fill Pressures Rapid Fill Times
A: -175 / 12mbar A: 3 / 4ms
B: 10 / 1mbar B: 0 / 0ms
C: 177 / 4mbar C: 13 / 5ms
D: -118 / 10mbar D: 3 / 1ms
E: 177 / 10mbar E: 18 / 3ms

The following photos are the worn parts.
-Front aluminum flex disk
-Rear rubber flex disk
-rear differential mount

[addy27]

While you're at it, try to ensure your engine mounts are good as well. I had a clunk at take off which sounded like it was coming from the rear, but was due to the engine mounts being worn/leaky..

[Surly73]

Originally Posted by Nemo550

Thank you Slury, your input had helped. I was able to take my vehicle to the auto hobby shop on base and start digging into my car. Just enough to see that the flex disk is worn. I didn't have time to check the center support bearing but ordered one anyways.
What do you mean by TC?

Update:
Upon inspection, the rear flex disk is worn. As for the front flex disk. It seems

Hey Nemo - sorry I haven't been by here in a while. TC = torque convertor

Nice post, with real info. Good approach, thank you for contributing!

[Nemo550]

It's okay Slury, I haven't been on here either. Thank you, I'm wondering if we could tell what's wrong with the driveline by reading the trans adaptations. The biggest variable would be how individuals drive.

Thank you addy, I will have have the dealer inspect that as well.

Update: I had replaced the rear flex disk, and ran out of time. So I couldn't replace the center support bearing or the rear diff mounts. Well the rear diff mounts were my fault because I was intoxicated, and ordered one for the front and one for the rear. Lol
Also if you order flex disk hardware make sure you get the right size bolts. There are a few different types you can get for your vehicle.

NOTE: Don't forget to remove the exhaust ground cables before dropping the exhaust to remove the heat shielding.

After replacing the flex disk. I noticed that the clunk was unfortunately still present. Even though that the center support bearing still looked great. I did the thing and stubborn man would do when he has to move. Drive it but only do the speed limit. Needless to say I drove the 19 hours. Only stopping for gas. Every stop I took the clunk got worse and more concerning. Took the vehicle to the dealership the next morning. When the looked it over they had come to the conclusion that it was the transfer case. Which thank god it was covered by the warranty I had purchased. I will keep everyone updated on what the exact cause of the clunk is.

Following photos:
- Rear flex disk before removal
- Rear flex disk after removal
- Center support bearing

[Nemo550]

Update:

The dealership replaced the transfer case (OEM) and the clunk was still there. Upon further investigation they had come to the conclusion that the transmission was bad. The warranty inspector came out, and told them to put the old transfer case back in the vehicle. While they put a new OEM transmission in. Which has to come from Germany and will take about a month.

The following are the estimates:
-12,000 USD for the transmission
-5,000 USD for the transfer case

Warranty cost 3,000 USD

I'm not sure how the trans fluid could be burnt at only high 40k miles. The vehicle was purchased used, but it just seems odd. I've never had any transmission issues with any vehicle I've had.
Now I'm stuck with a 4 cylinder Kia Optima until my vehicle is fixed.

Will keep everyone updated on the cause of the clunk. Also will include the new adaptation values when I get the car back. That way we have a decent control to use when looking at adaptations.

[AM Jahan]

Originally Posted by Nemo550

Update:

The dealership replaced the transfer case (OEM) and the clunk was still there. Upon further investigation they had come to the conclusion that the transmission was bad. The warranty inspector came out, and told them to put the old transfer case back in the vehicle. While they put a new OEM transmission in. Which has to come from Germany and will take about a month.

The following are the estimates:
-12,000 USD for the transmission
-5,000 USD for the transfer case

Warranty cost 3,000 USD

I'm not sure how the trans fluid could be burnt at only high 40k miles. The vehicle was purchased used, but it just seems odd. I've never had any transmission issues with any vehicle I've had.
Now I'm stuck with a 4 cylinder Kia Optima until my vehicle is fixed.

Will keep everyone updated on the cause of the clunk. Also will include the new adaptation values when I get the car back. That way we have a decent control to use when looking at adaptations.

Hi, and thanks for sharing your diagnostic information.
So, finally what was the cause of clunk noise? Did the transmission replacement remove the issue?

Regards,