[jspbtown]

OK...I have a 2004 645ci with 55k miles. Yesterday I started getting that "hiccup" around 1500rpm and 40 mph. Its easily reproducible. If I press the "sport" button it is greatly diminished.

I am also getting a periodic "dynamic drive malfunction warning". This warning is not totally unusual for me. I might get 2 or 3 over a week and then they don't come back for months. They never stay on and always clear when the key is turned off. I have gotten two in the past two days. I don't know if it is coincidental of contributory.

So I am ready and seeing several possibilities and I wonder if people could suggest the best course of action. So far I am thinking:

1. Tranny filter (yes..I know the pan) and synthetic fluid
2. programming update(?)
3. Battery issues(?)


If the fluid change whats the best fluid for these cars?
Idea? Thoughts? any suggested alternative order? Or anything else to try?

 

[jspbtown]

I am thinking of using Red Line D4 ATF as well. I used it in my Cayenne and it helped smooth out the shifting a lot.

And reasons why I shouldn't?

How much fluid do I need?

 

[HerbP]

I am thinking of using Red Line D4 ATF as well. I used it in my Cayenne and it helped smooth out the shifting a lot.

And reasons why I shouldn't?

How much fluid do I need?

You could possibly use that oil, but I am not sure if it meets BMW spec. A BMW tranny is quite different from a US made care, & requires a different maintenance guideline. I will attach a PDF file for you to follow.

If you are getting a Dynamic Drive problem as you describe, your voltage regulator is most likely bad. The alternator goes into an overcharge condition, & spikes the voltage above 15.8 volts. The modules start shutting down at this point, to protece them from damage. The alternator will need to be removed, to get the VR out. The VR is around a 75.00 or less item, off of the internet stores. A new alternator can be purchased for 300.00 if you decide to go that route.

 

[jspbtown]

Thank you Herb

According to RedLine the fluid will be fine. I had a terrible 2-1 downshift bang in my Cayenne and it totally cleared it up so I am hoping for some magic.

My hiccup seems to be in 5th gear right around 1500rpm and 40 mph.

I am hoping it is not a mechatronics issue.

 

[jspbtown]

Big day under the car today. Changed the pan (filter) and added in the Redline fluid. Took the car for two drives (about 20 minutes each) and the hiccup is gone

I did not replace the sleeve. There was ZERO chance of me getting that thing out and even less of a chance of getting the new one in. Anyone who does it must have baby sized hands. I could maybe just touch it with the tips of my fingers. It was WAY too tight to get my hands in there. It was bone dry so I left it.

I did end up stripping 3 bolts. The new design is so much stouter then the old one. I ended up getting just 6 new bolts because I had to get them from BMW. For those considering doing a fluid change order the bolts. Its well worth the $20 or so. Filling it with very hot exhaust pipes while the car was running was a treat. You need to be very very careful not to touch the exhaust.

Keep your fingers crossed.

 

[jspbtown]

Also changed the voltage regulator and threw in a new serpentine belt since mine was 12 years old (still looked great).

Someone did a write up on removing the alternator and I followed those instructions. One thing I noticed was that they suggested removing the center cap of the idler pulley to get a wrench on a torx to release the belt tension. Well there is actually a torx hole just to the right of the pulley that is designed to be used to release the tension. No need to remove that plastic cap.

Also there is a small tube that goes across the top of the fan shroud. When I went to move it it snapped in half. It was very brittle. I went to BMW to get a section of plastic tube and was told it was non-serviceable and you had to but the entire component (two sections of rubber hose and the plastic pipe). My car had a mid-year design change and they did not have the part in stock (around $70) and I needed the car so I found an alternative. I removed the two clamps that held the hose ends to the tube and took a section (18") of 5/16 brake line and some stainless hose clamps. Looks like it will work just fine for $7.00

Now when I reconnected the battery and started it I had about 7 error messages. Most have cleard except a passenger restraint error and a rollover protection error. I am hoping they clear with some more driving.

I did hook up my OBD scanner and the voltage was rock steady at something like $13.568 volts. Hoping this helps with my dynamic drive complaints.

 

[HerbP]

Also changed the voltage regulator and threw in a new serpentine belt since mine was 12 years old (still looked great).

Someone did a write up on removing the alternator and I followed those instructions. One thing I noticed was that they suggested removing the center cap of the idler pulley to get a wrench on a torx to release the belt tension. Well there is actually a torx hole just to the right of the pulley that is designed to be used to release the tension. No need to remove that plastic cap.

Also there is a small tube that goes across the top of the fan shroud. When I went to move it it snapped in half. It was very brittle. I went to BMW to get a section of plastic tube and was told it was non-serviceable and you had to but the entire component (two sections of rubber hose and the plastic pipe). My car had a mid-year design change and they did not have the part in stock (around $70) and I needed the car so I found an alternative. I removed the two clamps that held the hose ends to the tube and took a section (18") of 5/16 brake line and some stainless hose clamps. Looks like it will work just fine for $7.00

Now when I reconnected the battery and started it I had about 7 error messages. Most have cleard except a passenger restraint error and a rollover protection error. I am hoping they clear with some more driving.

I did hook up my OBD scanner and the voltage was rock steady at something like $13.568 volts. Hoping this helps with my dynamic drive complaints.

The plastic line is a very common failure. The passenger restraint error is most likely from a old dead battery. It can not be rest with a common OBD2 code reader. Try charging the battery for 12 hours to see if it will clear. Your voltage should be 14.24 volts with the engine running.

 

[jspbtown]

Interesting..

I never had any of those failures with the battery I had in there.

I will try charging. 14.24 volts at the battery?

 

[HerbP]

Charging at the battery will not make any difference, & it is preferred to charge under the hood.

 

[jspbtown]

Well...

Changing the voltage regulator has changed the dynamic drive issue and not resolved it.

Prior to changing the voltage regulator I would get two different dynamic drive errors. The first was a tone, an indicator between the tach/speedo, and a small message on the main screen. The second type of error message was basically the same but with a large warning on the main screen. Since changing the voltage regulator on Friday I have gotten the smaller (ie: no warning with explanation on main screen) warning twice. It clears after restarting.

Tranny seems a lot better. At first I seemed to have the hiccup but I drove it in manual mode for a bit, leaving it in 5th gear a little longer in the rpm band, and things have seemed to smooth out.

I still have the passenger restrain and rollover protection errors. When I was doing the work I had the car jacked up where the rear wheels were supported and the front wheels were hanging. I wonder if this might have set off the rollover protection? I also had a cooler with drinks on the passenger side seat when the battery was disconnected and then reconnected. I wonder if this might have been the reason for the restraint error? Either way I am thinking I will need to get them cleared.

I also checked my battery and there is no green indicator. I have no idea as to its age. I have been charging it at night and it seems to make the car run a bit better...but after two nights on the charger I still got a dynamic drive error this morning.

I still need to check the voltage with the car running. I did check it after a 1 hour drive (not running) and it was 12.4 volts. It dropped to about 12.2 when I turned on the headlights.

 

[HerbP]

Changing the voltage regulator has changed the dynamic drive issue and not resolved it.

Prior to changing the voltage regulator I would get two different dynamic drive errors. The first was a tone, an indicator between the tach/speedo, and a small message on the main screen. The second type of error message was basically the same but with a large warning on the main screen. Since changing the voltage regulator on Friday I have gotten the smaller (ie: no warning with explanation on main screen) warning twice. It clears after restarting.

Tranny seems a lot better. At first I seemed to have the hiccup but I drove it in manual mode for a bit, leaving it in 5th gear a little longer in the rpm band, and things have seemed to smooth out.

I still have the passenger restrain and rollover protection errors. When I was doing the work I had the car jacked up where the rear wheels were supported and the front wheels were hanging. I wonder if this might have set off the rollover protection? I also had a cooler with drinks on the passenger side seat when the battery was disconnected and then reconnected. I wonder if this might have been the reason for the restraint error? Either way I am thinking I will need to get them cleared.

I also checked my battery and there is no green indicator. I have no idea as to its age. I have been charging it at night and it seems to make the car run a bit better...but after two nights on the charger I still got a dynamic drive error this morning.

I still need to check the voltage with the car running. I did check it after a 1 hour drive (not running) and it was 12.4 volts. It dropped to about 12.2 when I turned on the headlights.

You are going to need the proper tool to reset the air bag problem, such as the BMW type. I had an ARS error on my 750 around a month ago, & it set off 7 different module errors. After a lot of head scratching & I could not figure out what the problem was, I check the power steering fluid. It was low & the low level sensor. As soon as I put some fluid in, I heard the modules starting up, like opening a door. My ARS problem went away, & all of my module errors reset ok. There are so many things tied together with the Dynamic Drive, it makes troubleshooting tough.

The battery test needs to be done after the car has set all night, with no charger connected. Turn the lights on, & read the voltage at the jump terminal. Anything below 12 volts, the battery should be changed. My battery on my 750 tested good at 2 different shops, yet it was bad. I suggest to go ahead & install a new battery, & check your PS fluid level.

 

[jspbtown]

PS fluid is fine

When I first got the car I sucked the power steering reservoir out and refilled it with clean new fluid (yes...the correct BMW type).

I have now charged my car for 3 nights overnight. Each time between 9-12 hours. I have my charger set at 2 amps. My charger has a yellow light when charging and a green light comes on when fully charged. Interestingly I have yet to see a green light on the charger even after 10 hours of charging. I find that weird.

 

[HerbP]

That sounds like it has a bad cell, or something is draining the battery as fast as you are charging it?