automatic transmission issues

**2mbb** · 09-19-2019, 10:57 AM

I have a 2003 325i with the M56 engine. I'm not sure which transmission I have, but the original transmission completely stopped working about 5 years ago and it was replaced with a rebuilt one.

I currently have two symptoms, both occur with the transmission in drive (D):

1. When coming up to a stop sign, or slowing down, the car will jerk. This seems to be a hard down shift (from 2nd to 1st I guess). It doesn't happen if I put the car in Neutral, or if the transmission is in Sport (S) mode. It is a similar feeling when a manual transmission is downshifted with having the engine RPM too low.

2. When driving and trying to increase speed, the engine will sometimes lug until the transmission downshifts--it makes a noise and has no power. This usually happens when I am driving at moderate speeds (25 to 40 mph). It is very similar to lugging the engine (eg. late downshift) in a manual transmission car. This happens for about 1 second before the car downshifts. Again, if I have the transmission in Sport (S) mode, this doesn't happen.

Any recommendations what to do, besides driving around in Sport mode all the time?

Thanks in advance.

**All2kool** · 09-19-2019, 02:42 PM

The first time I ever drove in 'S Mode' was on a hot day two years ago. It was also the first time I ever had a hard downshift. Didn't happen again until a month or so ago after having climbed a hill on a warm day - several weeks after having the transmission filter and fluid changed. Once the transmission cooled down, the hard downshifts disappeared. The advice I got was that a new transmission may be in my future. Some other advice I got was that 're-flashing' the transmission could be a fix.

I've decided to avoid driving in 'S Mode' and also avoid steep hills on hot days.

**whiskychaser** · 09-19-2019, 04:41 PM

The TCM makes shifts based on what the sensors tell it. It really doesn't know how much actual power the engine has. So it could be as you say - the car simply hasn't got enough. Does it run/pull OK?

**2mbb** · 09-20-2019, 09:59 AM

Originally Posted by All2kool

The first time I ever drove in 'S Mode' was on a hot day two years ago. It was also the first time I ever had a hard downshift. Didn't happen again until a month or so ago after having climbed a hill on a warm day - several weeks after having the transmission filter and fluid changed. Once the transmission cooled down, the hard downshifts disappeared. The advice I got was that a new transmission may be in my future. Some other advice I got was that 're-flashing' the transmission could be a fix.

I've decided to avoid driving in 'S Mode' and also avoid steep hills on hot days.

Thank you. I don't think I will put another transmission in this car.

Is re-flashing the transmission a dealer-only thing?

Thanks.

**2mbb** · 09-20-2019, 10:08 AM

Originally Posted by whiskychaser

The TCM makes shifts based on what the sensors tell it. It really doesn't know how much actual power the engine has. So it could be as you say - the car simply hasn't got enough. Does it run/pull OK?

Thanks for your reply. The car does seem to have enough power. I have another E46 with the M54 engine and they are about the same power-wise. And the lugging will immediately stop when the car does downshift. It's just that it comes in a little too late. The other car does not have this same symptom.

My son has been driving the car the last two years, and I have just started driving it more regularly for the last month or so. I'm not sure how long this issue has been happening.

Thanks.

**Muzz258** · 09-20-2019, 04:57 PM

Have you read the error codes from the transmission computer?

**All2kool** · 09-21-2019, 09:58 PM

Originally Posted by All2kool

The first time I ever drove in 'S Mode' was on a hot day two years ago. It was also the first time I ever had a hard downshift. Didn't happen again until a month or so ago after having climbed a hill on a warm day - several weeks after having the transmission filter and fluid changed. Once the transmission cooled down, the hard downshifts disappeared.

I should have clarified my initial post - the hard downshifts occurred AFTER having driven in S Mode and only after switching back to normal mode. It happened again today - very slight hard downshifts that went away after switching to S Mode - just as the OP indicated. Although not that warm out today, it was about 70 and as always, I was driving very conservatively, as I always do.

So what's up with our cars?

**BidNo** · 09-29-2019, 10:04 AM

BMW service interval on transmission fluid + filter is now 100k miles. Changing mine resolved some rough shifts. If you're near that mileage, verify there are no transmission codes, and change that first. GL

**MarcoZandrini** · 09-30-2019, 08:16 AM

Any shop that specializes in bimmers should be able to reflash the TCU (EGS in BMWspeak). Try www.bimrs.org to find a reputable indie shop that specializes in bimmers in your area. Also, have the shop change the fluid and filter. BMW’s 100k service interval is BS. Why? Most folks drive their car in a lot of stop and go traffic, and short distances (less than 10 miles). That’s hard on the transmission. A more reasonable interval is 50k-60k miles. At 100k miles the transmission fluid should be flushed using the 2 transmission fluid cooling hoses that run up to the fluid heat exchanger. Why? Draining the fluid and changing the filter only get about 50%-60% of the fluid out.

**2mbb** · 03-19-2023, 05:51 PM

So I guess I will reopen this thread...I am the OP for this thread. my son has been driving the car. He doesn't drive very much and I don't really get any feedback. I was driving it recently. It is having difficulty shifting from 2nd to 3rd. The faster I accelerate the longer it stays in second, then at some point it "jumps" (hard) into 3rd. At one point I had the "gear" warning sign show up. But I turned of the engine and it went away. When I got home I looked for DTC but there were not any. The Bentley manual doesn't really have any information on troubleshooting. Any ideas what the issue might be, or how to go about troubleshooting?

I did try to check the ATF level. The fill plug is in such an inconvenient space. when I cleared the plug cleared the threads fluid started coming out, but I couldn't get the plug back in. Long story short, between 2 & 3 quarts of fluid came out of the fill plug! Could it really be this overfull? Do I need to put more fluid into it?

Thanks for your help.

**E39 Newbie** · 03-21-2023, 04:24 AM

Originally Posted by 2mbb

So I guess I will reopen this thread...I am the OP for this thread. my son has been driving the car. He doesn't drive very much and I don't really get any feedback. I was driving it recently. It is having difficulty shifting from 2nd to 3rd. The faster I accelerate the longer it stays in second, then at some point it "jumps" (hard) into 3rd. At one point I had the "gear" warning sign show up. But I turned of the engine and it went away. When I got home I looked for DTC but there were not any. The Bentley manual doesn't really have any information on troubleshooting. Any ideas what the issue might be, or how to go about troubleshooting?

I did try to check the ATF level. The fill plug is in such an inconvenient space. when I cleared the plug cleared the threads fluid started coming out, but I couldn't get the plug back in. Long story short, between 2 & 3 quarts of fluid came out of the fill plug! Could it really be this overfull? Do I need to put more fluid into it?

Thanks for your help.

The trans fluid needs to be checked with the engine running, with the fluid between 30 and 50 degrees centigrade. If you just pulled the fill plug when the car was off you may have lost a bunch of fluid. You must refill it first by filling it until it dribbles out the fill plug. Replace fill plug, run the car until the trans fluid reaches the required temperature, pull the fill plug and fill until fluid dribbles out the fill plug hole again. Replace fill plug using a new crush washer.

Harsh shifts can sometimes be cured by changing the trans filter and fluid. However, often they are caused by malfunctioning solenoids. Usually a malfunctioning solenoid will throw a code. What scanner did you use when you checked for codes? A generic OBD II scanner will not work.

Sometimes they are caused by worn clutches. The trans knows that a particular clutch is slipping and will increase pressure to compensate, often resulting in a harsh shift. This problem requires a trans rebuild.

**2mbb** · 03-21-2023, 02:38 PM

Thanks for the reply. The fluid was warm and I had been driving it around so I thought I had satisfied the instruction to cycle through all the gears. But I did fiddle around quite a bit to figure out how to break loose the fill plug so perhaps in that time the ATF drained back into the pan.

I followed all the instructions yesterday, found the level low, and was able to get most of what came out back in. So clearly I did something wrong the first time. I ordered a kit to replace the filter and fluid so I’m waiting for that.

The scanner I use is a foxwell NT 650 elite. I think it will show transmission codes. I have another, older one more specific to BMW s I’ll give that a try later today. Thanks.

**2mbb** · 03-22-2023, 11:44 AM

Originally Posted by E39 Newbie

The trans fluid needs to be checked with the engine running, with the fluid between 30 and 50 degrees centigrade. If you just pulled the fill plug when the car was off you may have lost a bunch of fluid. You must refill it first by filling it until it dribbles out the fill plug. Replace fill plug, run the car until the trans fluid reaches the required temperature, pull the fill plug and fill until fluid dribbles out the fill plug hole again. Replace fill plug using a new crush washer.

Harsh shifts can sometimes be cured by changing the trans filter and fluid. However, often they are caused by malfunctioning solenoids. Usually a malfunctioning solenoid will throw a code. What scanner did you use when you checked for codes? A generic OBD II scanner will not work.

Sometimes they are caused by worn clutches. The trans knows that a particular clutch is slipping and will increase pressure to compensate, often resulting in a harsh shift. This problem requires a trans rebuild.

My drain plug has an elastomer gasket build into the fill plug. I didn't find a crush washer also installed and I don't see a crush washer in the RealOEM parts diagram (5HP-19 transmission). The fill nut was on so tight I started to strip the hex socket head. That's another reason I got the filter kit--it comes with a new fill and drain plug.

**E39 Newbie** · 03-22-2023, 12:55 PM

Originally Posted by 2mbb

My drain plug has an elastomer gasket build into the fill plug. I didn't find a crush washer also installed and I don't see a crush washer in the RealOEM parts diagram (5HP-19 transmission). The fill nut was on so tight I started to strip the hex socket head. That's another reason I got the filter kit--it comes with a new fill and drain plug.

You're correct. I misspoke. Both the drain plug and the fill plug have an o-ring seal.

**harrier** · 03-27-2023, 07:40 PM

Do you have any leaking around the bell housing?
Hard shifts are caused by fluid pressure, which could be a worn valve in the valve body, a weak solenoid, low fluid, a failing torque converter, or a failing pump seal.

It can also be a failing gasket in the valve body. I would pull the valve body and disassemble to see if the gasket has failed or there is excess wear on one of the valve cylinders.

If there is leaking at the bell housing then you will need a new pump and TC

**harrier** · 03-27-2023, 07:41 PM

You have a ZF 5hp19 transmission. All m56s do

**2mbb** · 03-27-2023, 09:36 PM

so I pulled the pan off to replace the filter and the bottom of the pan is literally coated with a residue that is difficult to scrape off. The compressed sludge was "gluing" the magnets to the bottom. using a plastic putty knife I can curl up sections of the sludge that resembles water logged leather. I don't have a true solvent bath so I'm thinking I'm going to have to replace the pan. My concern is, if this is what is in the bottom of the pan, what does the rest of the transmission look like?

Before opening up the transmission, I used some other scanners I have. On one of them I got messages such as "P0782 (2 - 3 shift malfunction)", "SYMPTOM: Glue", "Glue: Check 2/3". I googled "GLUE" in this context and found out it refers to fluid solidifying and sticking inside the transmission.

Once I get a new pan, I'm thinking I need to flush the transmission with something that will dilute and remove the glue. Does anyone have any suggestions?

The original transmission stopped working in 2013 (120K miles) and I had it replaced at a shop with a rebuild transmission. Now the car has 180K miles. seems like a lot of sludge to build up in 60K miles?

**harrier** · 03-27-2023, 11:49 PM

Can you take a picture? I wonder if you got water in the case.

If so you need a new tranny or complete rebuild and you should check the transmission cooler block at the radiator to see where you hit the intrusion

**MarcoZandrini** · 03-28-2023, 07:20 AM

Before you try flushing the transmission to get rid of the glue, I’d contact ZF to see what its technicians recommend. In the end you may have to have the transmission serviced by a ZF authorized shop.

This is a perfect example of why “lifetime fluids” was a marketing ploy and not a maintenance philosophy.

**2mbb** · 03-28-2023, 09:19 AM

Thanks for staying with me guys.

I have attached some pictures of what I am dealing with. I scraped off most of the sludge and now I seem to be left with something more like shellac. The sludge was like a compacted mud. I tried to loosen it with spray water-based degreaser (simple green and something else I have in a spray bottle). I also used brake cleaner. I think today I might try oven cleaner. I don't know what water in ATF looks like, but this doesn't look like an emulsion. It does look like sediment or sludge.

This is a picture of the sludge I scraped out yesterday that is in my garbage can:

Screenshot 2023-03-28 061109.jpg

This is a picture of the pan. I let it sit in simple green overnight then rinsed it with water. this is why it looks like there is water.

Screenshot 2023-03-28 061208.jpg

This is a picture of some of scrapings from today:

Screenshot 2023-03-28 061237.jpg

Thanks for your help.

**harrier** · 03-28-2023, 10:37 AM

That looks awful

Hard to tell from the pictures, but are there metal flecks? Brown fluid suggests overheating and oxidation, and your system isn't working because there is no flow. If there are flecks, then your steels are likely toast.

I would not use that transmission without inspecting the friction discs, which means pulling the valve body and the pump. If it overheated the friction discs and the steels will be toast. If there was water intrusion the friction discs will be toast. Only way to know is to open it up.

You should also pressure test your transmission cooler core to see if it has cracks, and find a way to make sure that brown crap is not in the cooler lines. It is possible that they are stopped up.

**2mbb** · 03-28-2023, 02:32 PM

Thanks for the input. I haven't really looked at the inside of the transmission. I took the pan off and saw that mess but didn't really inspect inside.

For full disclosure: (1) I have two 2003 E46. This one has the ZF transmission, the other has the GM transmission. I have not been keeping a record of what maintenance I do and because they are so similar, I get confused. I did order a kit for the GM transmission (filter and fluid change). I see the filters are substantially different, so I think I would not have used the GM kit on the ZF transmission, but I can't be sure...I'll confirm tonight but the filter I saw when I took the pan off looks like the ZF filter. (2) This car with the ZF transmission did over heat the engine some years ago (2015/16 I guess). I was driving home and the coolant expansion tank broke and dumped all the coolant. I limped it in to the next town to a shop. the shop was able to replace the coolant tank, pump etc. and the engine, so far, has been fine. However, I didn't think about the transmission. I don't remember if I got any transmission related warnings at that time...

**E39 Newbie** · 03-28-2023, 03:01 PM

Originally Posted by 2mbb

Thanks for the input. I haven't really looked at the inside of the transmission. I took the pan off and saw that mess but didn't really inspect inside.

For full disclosure: (1) I have two 2003 E46. This one has the ZF transmission, the other has the GE transmission. I have not been keeping a record of what maintenance I do and because they are so similar, I get confused. I did order a kit for the GM transmission (filter and fluid change). I see the filters are substantially different, so I think I would not have used the GE kit on the ZF transmission, but I can't be sure...I'll confirm tonight but the filter I saw when I took the pan off looks like the ZF filter. (2) This car with the ZF transmission did over heat the engine some years ago (2015/16 I guess). I was driving home and the coolant expansion tank broke and dumped all the coolant. I limped it in to the next town to a shop. the shop was able to replace the coolant tank, pump etc. and the engine, so far, has been fine. However, I didn't think about the transmission. I don't remember if I got any transmission related warnings at that time...

Holy crap!! I've been in my share of transmissions and I've never seen one that bad. That looks like severe overheating, although I have no way of verifying. I can say that it's bad. Really bad.

That trans needs to come out of the car. But first I think I'd disconnect the cooler and blow some air through it and see what comes out. If nothing comes out, time for a new cooler. If more of that gunk comes out, new cooler.

Also, do you know what kind of fluid the shop put into it? It's important to use the correct spec fluid. I use Liqui-Moly 1200.

I'll bet your solenoids and probably the VB are full of that stuff, too.

I have had good luck with kerosene for cleaning trans parts. For baked on carbon I've had good luck with carb cleaner, the kind that comes in the metal bucket.

**2mbb** · 03-30-2023, 08:45 AM

So I got the pan cleaned up pretty good, I think. I ended up using spray oven cleaner: Apply, wait, scrub...repeat. Surprisingly, the underside of the valve body looks pretty good. I also did the recommendation to blow out the ATF cooler attached to the radiator, and that seemed pretty much drained and empty. I also pressure tested my cooling system and didn't find any leaks.

I appreciate all the feedback so far, but what I'm going to do next is replace the filter and fluid with new. I might add some type of ATF additive that is supposed to "clean". Then run the car for a (short while) and replace the fluid/filter again and maybe a third time.

If I have to replace the transmission, I'll probably just junk the car. At least the first time we replaced the transmission it was expensive, and probably cost more than the car is worth. Thanks for all the hep and advice so far!

Screenshot 2023-03-30 053615.jpg

**2mbb** · 04-04-2023, 08:41 AM

So just to give a short update, I scraped all the gunk out of the transmission pan (see above), replaced the AT filter and replaced the pan. Then I added 1 pint Seafoam Trans Tune and topped off the rest of the transmission with Valvoline MaxLife ATF. Per the Seafoam instructions, I drove the car around for 30 miles, then I drained the fluid (left the pan on this time) and replaced it with another pint of Seafoam and new Valvoline Maxlife ATF. I am going to drive the car for another 100 miles or so before replacing the filter and the fluid one more time (I don't plan to add anymore Seafoam after the second application).

During the 30 mile drive the transmission started shifting much better. My original complaint of hard shifting between 2 and 3 seems to be resolved. I did not get the "gear" shaped warning, although I have not checked for codes. I did use INPA to monitor my transmission temperature and it seemed to be OK. after driving on the freeway for 15 minutes or so, the transmission temp went up a little bit above the engine (radiator) temperature of 90C. If I remember correctly, the transmission stayed below 120C. I'll continue to monitor over the next 100 miles.

The fluid I drained out after the 1st Seafoam application (30 miles of use) was black and seemed to have a fair amount of visible but small particulates. However, the viscosity seemed similar to new fluid and it was not sludgy.

Thanks for the help!