BimmerFest BMW Forum banner

E46 Transmission slipping on 1st to 2nd

29232 50

First time I post a question on the forum, I looked and search, but wasn't able to find the answer, I did find few pointers on what the issue is, but I need a very good way to explain this to my mechanic since I keep getting that the transmission is fine and if there aren't any ODBII codes then there is nothing wrong.

Car: BMW 328i
Year: 1999
Transmission: GM A5S360R SW
Miles: 220,000

Work: Transmission total rebuild including new torque converter.

History: About a two months a go all the transmission oil was spilled out and the car didn't move, transmission fluid was charcoal black and I did the fluid change not long ago so I took the car to a nearby transmission repair shop with a sign listing BMWs.

Symptoms: After the total transmission rebuild according to receipt for $1500 I took the car for a test drive and just few blocks out the gear light came on, took it back to the shop and the code was something about "gear ratio", so they change the Pressure regulator solenoid.

Since then I have taken the car back to the shop 3 times on the following complains and so far the answer is that there is nothing wrong with the car.

Complains: The car drives just fine in the morning and or cold, the issues start when is hot and I have driven for 10 or more miles on the FWY.
When at a stop light or taking off the car will do this jerk going from 1st to 2nd it feels like is slipping, but not fully slipping - is almost like if the clutch disk are worn out in just sections and it grabs and slip, grab and slip, grab and slip etc.... it do that for about 2 seconds until it goes into 2nd and then I can feel it just a bit going from 2nd to 3rd, but very little almost unnoticeable.

Notes: The second time they gave me the car back after replacing the Pressure regulator the car was low on transmission oil, that was found on my third visit when I complain that they had messed up the transmission oil plug and when they were replacing it I noticed the car was not dripping oil even that the car was hot, they top off with almost a quarter and a half.
BTW: after they added oil the car stop doing this wining noise. I never complain about that because the mechanic told me it was the idle pulley making the noise.

The Question: :dunno: What causing this transmission slipping even after a total transmission rebuild? They also installed a new torque converter.
I need to be able to prove to this guys that they did a bad job and they need to fix it OR if this is normal then why the car never did that?

I suspect from doing my own research, they might have installed a torque converter that is not specific for this transmission, the clutch disks already messed up due to the low transmission fluid and running it like that for a month, bad pressure affecting 1st to 2nd gear.

Thank you so much in advance.
1 - 20 of 51 Posts
Running low on fluid probably smoked the clutches for 2nd. I bet it will slip underload if you put it in 2nd and then accelerate.
Thanks crowz,

I just did the following:

On each test I stop along side of the road full stop, then I'll press the gas to rep up the car to about 2500 - 3000

1. put the car on S2 and rev up the car, no slipping or not the way I described earlier. I'll need to hook up my laptop (INPA) and see if there is a shift from 1st to 2nd. The car RPM went as high as 4000 and I didn't noticed a gear change.

2. put the car on S3 and yes the car do the jerky slipping from what I think is 1st to 2nd :confused:

3. same for S4, the car will do the jerky slipping from 1st to 2nd

RESULTS: It looks like the test indicates the slipping is actually from 2nd to 3rd since is not doing it on S2, but then at the same time I don't feel the car going from 1st to 2n on S2. Is the transmission jumping a gear ???

I'll do more testing tomorrow having INPA, I'm curious about the S2 results, is almost like there is no 1st to 2nd or the gear change is so smooth that is not noticeable.

crowz you are giving me a good pointer.

Running low on fluid probably smoked the clutches for 2nd. I bet it will slip underload if you put it in 2nd and then accelerate.
For most slippage deals on bmw's that Ive diagnosed for people the slippage like that is toasted clutches which you can narrow down by accellerating hard in the gear in question or its a bad valve body where a selonoid is bad or clogged. I wonder if this trans shop even rebuilt the valve body. Thats actually allot more common than you would think. Most iffy shops are scared of touching them it seems.

According to the shop, they did rebuild the valve body, but they did not put new solenoids, the only one they changed is the pressure regulator solenoid.
But I didn't have the slipping issue when the transmission went out, symptoms where intermittent no reverse (I changed that solenoid my self few months back "the one next to the pressure regulator solenoid"), I never had any transmission ODBII codes.
(same now, there are no ODBII codes) just the annoying jerk that is making me nerves.

The problem with "rebuilding" and not replacing the solenoids is on these particular transmissions replacing the solenoids IS rebuilding the valvebody. Most have 1 or 2 solenoids and then small check valves, balls etc. The trans we have has a solenoid for each gear basically. So for me to consider the valvebody rebuilt the solenoids are a must.

This is what I got after hooking up INPA.

1. Car works fine when transmission temperature is below 200 F
2. The slipping is happening on both 1st to 2nd and 2nd to 3rd gear when hot (230 F).
3. On S2 the engine RPM will go up to 5000 to shift to 2nd with slipping which also brings up the temperature of the transmission higher
4. Transmission temperature went up to about 300 F by doing this stop and go about 10 times in 20 minutes.
5. Once the transmission is around 270F and 300F the slipping happens even at low RPM when taking off from a stop (no load).
6. THIS IS A BIG ONE - noticed the transmission will start to get hot while on 5th, according to INPA 5th is "Torque Converter Clutch".

The torque converter do not engage on 1st so it is not the torque converter, read some article on difference between the up to 1998 and the 1999 to 2005 versions and is that, how well they tolerate heat, but is possible it gets the transmission hot and other problems arise from it.

a. All points to be related to the temperature.
b. Wrong torque converter,
c. Solenoids not working under high temperatures.

I'll search for transmission temperature specifications.

- My next test will be to drive on S4 - I notice on S4 (Sport Mode) the "Torque Converter Clutch" do not engage. This will tell me if indeed the Torque converter is the one to blame for the over heat of the transmission.

EDIT: I was wrong about S4 not engaging the "Torque Converter Clutch", went for a test drive and the transmission started to get hot again 240F, I didn't allowed it to get any hotter since that is not normal according to other on this forum.

What would be a good test to pin point if the thermostat is bad, the one under the expansion tank.
How can I find out what is making the transmission go hot?
Thats what I was going to suggest next.

Heres a link to the thermostat itself diagram wise.

When I test it I use an infrared thermometer. Just looked for massive temp changes :)
since a good infrared thermometer is $80 I went and got the thermostat for $84 + $12 50/50

I'll let you all know how it goes.

BTW: I started to monitor transmission temperature when warming up the car and the car warm up to 190F while the transmission was at 67F there is a good chance is the thermostats. If not then I'll be sure is something wrong with the transmission.

Took the car for a test drive today after I replaced the transmission thermostat (17111437362) :( unfortunately that did not make any difference in transmission temperatures.

After this test drive I pin point the exact temperature at which the slipping starts "213 F", the transmission keeps getting hotter few degrees after each stop and go.

Findings: I'm 100% sure now that the problems laid on the transmission it self.

BMW: Transmission Fluid Temperature Sensor
Detection of high fluid temperature modifies the torque converter regulation control and
modifies the shift program to aid in reducing transmission fluid temperature.
(Q: modifies the shift program in what way?)

1. slipping is getting the transmission oil hot per each stop and go making the slipping worse as the transmission reaches 300 F

Question: what is causing this slipping?
As you can see here those temps alone can cause it.

At this point I would suspect cluch or band failure with a possibility they were installed wrong.

But for one final test make sure the clutch fan is good on the car. Ive never seen it heat the trans up and not overheat the car but its possible I guess.

Use a rolled up newspaper to try and stop the mechanical fan while the cars idling. If it stops easily and starts back turning slowly its bad. If you cant stop it within reason then its good.

A bad clutch fan will overheat the trans. But again it usually causes engine cooling problems.
The fan clutch I can stop it with my hand if the car is just warming up, if hot then the news paper works, impossible by hand on those conditions. when hot it will spin up fast after stop.

Just tested the fan clutch again and just to make sure, I was able to stop it with my hand even when hot, I remember that was not the case before, humm I'm getting frustrated since that fan clutch is only a year old from ECS Tuning, I'll look up warranty.

Thanks for the transmission temperature range graph - helps a lot

BTW: INPA gives me a reading for transmission oil ageing at 99, it was 98 yesterday, is it possible to reset this value? trans oil is new.
At this point I would suspect cluch or band failure with a possibility they were installed wrong.

But for one final test make sure the clutch fan is good on the car. Ive never seen it heat the trans up and not overheat the car but its possible I guess.

Use a rolled up newspaper to try and stop the mechanical fan while the cars idling. If it stops easily and starts back turning slowly its bad. If you cant stop it within reason then its good.

A bad clutch fan will overheat the trans. But again it usually causes engine cooling problems.
Definite bad fan clutch. I wouldnt drive it anymore till getting that changed.
The Fan Clutch will be here in a week, I'll keep you posted.
Definite bad fan clutch. I wouldnt drive it anymore till getting that changed.

Ok, since I have a new fan clutch on its way, I went and bolted the current one, :( well this is bad, engine temperatures are the same as before and transmission temperatures the same, the only difference for the transmission it will take a bit longer to get hot.

My routine test: get on the FWY 5 miles one way 70 to 80 mph then I turn around and punch the gas on the in ramp which is a bit up hill so that I can enter the FWY at 65 mph, then most of the way back is down hill so I push the gas just a bit so I keep the car on a coast at 70 to 80 mph, from time to time I use the kick down (2 times way back).
When I get off the FWY on the first light that is when I start getting the slipping (transmission at 230F - engine at 190F)
Whit the fan always engaged there were no difference for the Engine, but transmission was at 220F when I got off the FWY, temperatures kept going up on ever stop and go.

Findings: The transmission still getting hot, it looks like cooling can't keep-up.
After the test I park the car and monitor transmission temperature while car at idle. Transmission will start cooling at 2 degrees per 2-3 minutes.

Once again, what is getting the transmission hot?
Like I stated from the beginning, I need to explain this to the shop, they keep telling me that the transmission is fine, that if there are no codes that there is nothing wrong.
The third time I took the car there, they kept it for a week just to tell me the same thing.

WHAT CAN I DO - should I just take this guys to court?
Few INPA Pics with readings

Still searching, I remember seeing somewhere that type "B" should be use on the BMW 328i 1999 with the A5S360R transmission and if the type "A" is use heat is the outcome.

If anybody out there knows anything about the type of torque converter please let me know, what I'm trying to find out is, if the wrong torque converter will generate excessive heat.

I Found this: Torque Converter info

3. Piston lining type

A. Paper (On/Off)
B. Carbon fiber ( PWM type I )
C. Woven graphite ( PWM type II )

(The correct piston lining must be used or apply problems/failure will occur. Computer strategy II requires a woven graphite lining due to almost continuous slippage in lock-up mode. Use the GM code or a scanner to determine strategy II systems).

From: ''

What is 'Controlled slippage ' ?

But the 'slippage' that the OE engineers came up with was a 'controlled slippage.' And in fact, the 'slippage' that they designed technically wasn't slippage at all. It was actually the rapid fire action of turning on (applying) and off (releasing) the torque converter clutch.
When we go to the theater to see a film, we call it going to the 'movies' or seeing a 'motion picture.' But these pictures really don't move, do they? If you look closely at the actual film that runs through the projector, you will see that the movie is really just a continuous and rapid fire display of individual 'still photos.'
The impression of the continuous / controlled slippage of the torque converter clutch is similar to the movie we see in the theater.
Although it seems as if the clutch is slipping, it really is just the rapid fire apply and release of the clutch, thousands of times per minute, just as a film shows thousands of individual still photos (frames) per minute.
What happens if you mismatch the converter to the application? Well, that depends. Putting a converter with a paper lining into a vehicle that uses PWM with the advanced EC3 strategy will likely experience converter failure very quickly, with a high probability of generating debris that will circulate through the transmission. Conversely, putting a converter with woven carbon friction material into an application that has on/off controls may not fail as quickly or as completely, but it could develop significant drivability problems over a short period of time.

Although different manufacturers use different terminology, the generic term that auto engineers have given to this quick fire apply and release of the torque converter clutch is 'modulation.' 'Pulse Width Modulation' (PWM) is only a more detailed description of the same strategy. 'Pulsing' the TCC 'release oil' is the way that the converter clutch is applied and released in a rapid fire method.

Identifying pulse Width Modulated systems that Use eC3 strategy.

As previously mentioned, transmission rebuilders can easily identify if a transmission is set up as being able to modulate the converter clutch. However, there is no way for rebuilders to tell how the PWM converter clutch is controlled. Is it an early style unit that simply modulates and 'ramps up' the clutch for a short period of time before full apply? Or is it an EC3 strategy that modulates the clutch on a continuous basis? Unfortunately, inspecting a transmission as it sits on a bench will not tell you what strategy is used to control the PWM converter clutch. Simply put, transmission teardown and inspection will tell you if a unit has PWM capabilities; teardown will not tell you the strategy by which PWM is utilized.

How a modulated converter clutch is applied is determined by the software programmed into the computer module that controls the
transmission. The only true way to determine if a vehicle uses the EC3 strategy is by hooking up a scan tool to the vehicle and monitoring
the way the TCC is applied.

Warning: Watch out for these Common pitfalls ***8226; There are now a variety of products and kits in the marketplace that typically modify TCC hydraulic systems in order to transform a PWM system into an on/off system. In general, when modifying a lock up system in this fashion, you should use a converter with a lining that is compatible with an on/off strategy. But always refer to the instructions from the conversion kit manufacturer for specifics.

***8226; Additionally, other OE manufacturers are using GM transmissions in their vehicles. Isuzu, BMW, Volvo, and others are all now using General Motors transmissions in limited applications. Even if a transmission shop has a scan tool that can access information in GM vehicles, that scanner may not be able to link with all other OEMs that use GM transmissions.

In conclusion, the type of friction that is used in a remanufactured torque converter is something that must be considered when choosing the correct unit for a specific application. And it is not going to get any less complicated. As GM and other auto manufacturers continue to face the demands of increased fuel economy, decreased emissions, and better drivability, torque converter clutches (along with the systems that control them) will only become more sophisticated. Learning the basics will help you get the correct torque converter to your customer the first time, now and in the future.
Also found this very interesting fix that describes exactly what my transmission is doing:

The transmission experiences a shudder when shifting from first to second gear under full throttle.
You need to take a look at the 1 -2 accumulator. First, check the condition of the spring found inside the accumulator. You want to make sure it is not broken. Next, take a look at the accumulator piston. Inspect it for cracks. Finally, take a look at the bore in which the piston rides in. Make sure the walls of the piston bore do not have any heavy scuff marks. Think of it as you would taking care of a new pair of shoes. You don't want scuff marks, not just because they don't look good, but they signify wear and tear. If it does, clean it them with a piece of emery cloth. Be sure to clean the bore with Brake Clean when done.

:confused: the more I investigate on what might be happening with my transmission now it looks like I have to issues:

1. torque converter
2. valve body
3. band failure (per crowz)

1 - 20 of 51 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.