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2004 BMW E46 320i Touring
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Discussion Starter #1 (Edited)
I'm having an EGS error reported by INPA.

49 Gear check.
Shifting up from 4>5

This started showing up about 800km ago. No rough shifting but bouncing revs on deceleration. To me it feels like the lock up clutch is engaging and disengaging during deceleration. The reported slipping in INPA, I can't notice.

I have had my auto box serviced by ZF here in the Netherlands. Before that service there was some bouncing of revs during deceleration from 60 kph
After the service and driving for a bit the auto box shifted as new and was very solid. Now about 9000 km later it developed the bouncing revs decelerating from 90 kph. It's also a bit more pronounced.

Since my 2004 320i touring has 270000 Km or 170000 Miles on the clock I'm going for the cheapest option first and check the oil level, but assuming this is good is there anything else I can look at?

Could this bouncing of revs be due to pressure issues in the trans caused by the pressure regulator or one of the solenoids?
 

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When you say bouncing revs, do you mean multiple times, or just as you start the deceleration. It is normal for the revs to jump up when you take your foot off the gas as the TC clutch is immediately disengaged to make the deceleration smoother.

If it doesn't seem to be just as you decel, is it doing this in all gears (when driving in manual mode) or just one?
 

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2004 BMW E46 320i Touring
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Discussion Starter #3
It is definitely bouncing revs. And at a very specific speed window.
Driving a steady 90 kph (55 mph) the trans is in 5th and lock up engaged. I take my foot off the throttle and revs will decrease a bit and after a second drop a further 500 rpm.
When it drops down to about 1200 rpm it seems to me the lock up clutch engages again and brings the rpm up by 500.
The trans will bounce the 500 rpm up and down until the car has decelerated to about 70 kph (40 mph). There the trans will settle on about 1000 rpm till you come to a stop.

Before the service at ZF the trans had this behaviour when decelerating from 60 kph. After the service where a flush and a deep clean of the valve body took place there were no issues for about 9000 km.

As far as I can tell there's no leaks on the trans and I'm assuming oil level is correct.
Hopefully I'll have some time this weekend to double check the oil level, but I have a suspicion the issue is related to pressure issues or a TC that's on it'a way out.

Any insight is very much appreciated!

I did check your DIY's but I do believe the issue above isn't covered.
 

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E30M3 Race F10 535 R1150Rt M Coupe
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I'm ZF trained (USA) and as far as I know the locking torque converter was only used on the larger displacement engines of 2.8 & 3.0L. Which do have issues. I would have to think (?) that your 2.0L does not have such.
 

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the people’s mod
2004 330Ci 115k miles
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I'm ZF trained (USA) and as far as I know the locking torque converter was only used on the larger displacement engines of 2.8 & 3.0L. Which do have issues. I would have to think (?) that your 2.0L does not have such.
All the USA E46s with AT have a PWM-controlled variable TC lockup clutch, regardless of engine displacement.
 

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E46 F10 W204 W212
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And I think the difference was the amount of friction surfaces for the lockup clutch. It’s in the training manual somewhere.
 

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2004 BMW E46 320i Touring
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Discussion Starter #7
I'm ZF trained (USA) and as far as I know the locking torque converter was only used on the larger displacement engines of 2.8 & 3.0L. Which do have issues. I would have to think (?) that your 2.0L does not have such.
My 320i definitely has a locking torque converter. The ZF 5HP19 transmission and torque converter for the M54B22 do have different part numbers compared to the 325 and 330. No clue what the difference is exactly but the transmissions for the 325 / 330 and 320, as far as I can gather, behave and operate the same. So I'm hoping someone here can guide me in the right direction to diagnose the issue.
Not looking forward to walk into a transmission shop and all they give me is the "need to rebuild/replace the tranny" line. I also would like to DIY and actually learn something along the way.
 

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What about live data from INPA?
Can you see pressures and valve positions?

I've never had an autobox, but other systems let you look at
useful diagnostics data like brake pressures, wheels speeds, etc.

all I got
t
no lockup mode.
 
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There isn't any way of working out the pressure, but if you have ISTA, it shows the voltage being applied to each solenoid. This can sometimes be helpful when diagnosing an issue.

Tim, is it only occurring in 5th? If you are at the same speed in 4th does it exhibit the same behaviour. I'm trying to work out if the problem might be with an individual clutch in the transmission itself or it might be with the TC clutch.

Of interest, the TC clutch is a single plate type, albeit the TC is a different spec for each transmission. The variation in transmission number is for differences in the number of friction/steel disks in some of the transmission clutch packs.
 

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I think I have the same problem here, 325i but a bit more problems starting to occur, like the car picks the clutch up harder after the gaspedal was released and picked back up while driving. I'm still not sure if it's a transmission problem or an engine(sensor) problem since they depend very much on eachother. My trans runs fine when in Manual mode btw. Are your problems present at all settings?

I have tried:
  • New spark plugs
  • 2x new trans oil at ZF (Holland)
  • New MAF (the one thing that actually changed the transmission behaviour a bit, but did not solve the problem)
  • New Coils
  • ECU and EGS updated
  • Reset adaptations (with INPA)
  • DISA rebuild

Possible solutions I have read about, I have not tried, but does no harm to do anyway.
  • Vanos rebuild
  • Throttle body cleaning
  • Lambda sensor replacement (before cat)
  • Vacuum leak test
  • Valve body replacement (inside trans)
 

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2004 BMW E46 320i Touring
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Discussion Starter #12 (Edited)
Gentlemen.
Let me first say thank you so much for the extra info and suggestions!
I'm hoping this will lead me and hopefully others to a resolution.

What about live data from INPA?
Yes on that. Info as @BaliDawg states is there but at the moment only have INPA running on a laptop that doesn't hold a charge. So I can check the info only while stationary. There is an option to check the function of the solenoids. They all work according to INPA. I'm thinking it's only a check if they go on / off?

There isn't any way of working out the pressure, but if you have ISTA, it shows the voltage being applied to each solenoid.
Wish I had ISTA-D in this case. I gather it's a pain to get your hand on and working?

is it only occurring in 5th? If you are at the same speed in 4th does it exhibit the same behaviour.
In 5th it's way more pronounced, but it does happen in 4th while in manual mode. When I have time I'll make a video to clarify better.

My trans runs fine when in Manual mode btw. Are your problems present at all settings?
Issues seem the same in manual and sport mode. I do need to take a more systematic approach at checking this though. I've been busy and the moments I have been able to check, it's been busy on the roads.

In the meantime bit more info about the car before I'm able to get it on a lift and after that take it for a methodical test drive.

- Transmission has been flushed and valve body has been cleaned by ZF service center about 9000 Km ago. Filter was original to the car and I assume oil had never been changed before 🤦‍♂️. The service did resolve previous bouncing revs issue.
Bouncing of revs previous to the flush did not produce an error in INPA.

  • EGS was already on the latest software (7546092) I have a feeling this had been done by a previous owner.
  • Resetting adaptations for EGS does nothing to the rev bouncing.
  • DME has been updated by me resulting in a waaaayyy smoother engine. No difference to behaviour of the trans.
  • Been on a hunt to get fuel trims to a minimum (spark plugs, pre cat O2 sensors, VCG, fuel filter, fuel pump and DISA replaced. A vacuum leak here and there has been plugged). LTF's are around 3% to 4% at the moment. CCV and a shitty thermostat (car is running a bit cool) are likely culprits to the remaining percentage points.

My theory is that engine health does not really relate to the bouncing revs in this case, but I might be very wrong.
 

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Another way of determining if it's the TC clutch is to compare transmission analog outputs as the bouncing is happening. You will need INPA working as you drive and the problem is occurring.

Open the TCM then go to 'status', then 'analog values'. Observe the engine RPM, Turbine speed (transmission input), and output speed.

When there is slip in the TC (normal ops), the engine RPM should be slightly higher than the turbine speed. The more slip, the greater the difference between the two. The more locking of the TC clutch, the closer the two. The clutch never completely locks, so you should always see the engine RPM slightly higher than the turbine speed. You will see the greatest difference between the two when the TC clutch is completely unlocked.

At a constant car speed, the output speed should be constant, as this is the direct drive to the wheels.

So when the problem is happening at a constant car speed, what is happening with the turbine speed as the engine RPM bounces. Does the turbine speed bounce with it, or does it stay constant.

If the turbine speed is staying constant, then the TC clutch is engaging and disengaging, meaning the remainder of the transmission clutches are remaining clamped correctly. I suspect this is most likely the case, and is then a matter of determining why.

If the turbine speed is bouncing, then there is slippage downstream somewhere in the transmission.
 

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2004 BMW E46 320i Touring
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Discussion Starter #14 (Edited)
@jjrichar This is good stuff.
I’ll get on this as soon as I have a way to get a working laptop in the car.

Today didn’t go quite as planned as far as methodical test drives. After replacing the CCV, a job devised in the depths of hell, a simple thermostat change turned into a shit show because of an aftermarket radiator hose. People might be onto something advising to only use OEM... 🤦‍♂️
I did check the trans oil level. Was good.
 
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