logo elektroda
logo elektroda
X
logo elektroda
Advanced Search
logo elektroda
Build faster with M5Stack »
Build faster with M5Stack » Stick • Unit • Cardputer
ADVERTISEMENT
Dostępna jest polska wersja

Czy wolisz polską wersję strony elektroda?

Nie, dziękuję Przekieruj mnie tam

Bmw e46 compact N42 automatic transmission - Valvetronic deactivation - what sid

wowka 18816 18
ADVERTISEMENT
Treść została przetłumaczona polish » english Zobacz oryginalną wersję tematu
Report a violation of the law
Reply | New topic
  • #1 17020667
    wowka
    Level 28  
    The car is an e46 compact, N42 engine, 1.8 116KM, automatic gearbox.
    A standard problem with a worn Valvetronic eccentric shaft, the engine burns heavily and practically does not run the 4th cylinder at idle speed, when you try to start it usually goes out. However, after disconnecting the shaft position sensor or the motor plug that moves the shaft, it sets to the maximum valve lift and the valvetronic system stops working. It seems that the car drives quite well then, but I have no comparison, because it is "fresh" imported from abroad.

    - Are there large differences in engine dynamics with and without a working valvetronic system?
    - Are there differences in combustion?
    - How will it work with an automatic transmission?
    - What are the other side effects of driving with Valvetronic not working?

    Questions why I do not fix it - it is difficult to get a shaft and levers, besides the price does not encourage and it is difficult to assess the condition by eye, so there is a high risk
  • ADVERTISEMENT
  • Helpful post
    #2 17020910
    SQ9MEM
    Level 29  
    The differences in dynamics will certainly be felt. The truth is that an engine with a damaged Valvetronic will never work properly, as confirmed by numerous reviews from the forum. Burning will be greater. I do not understand, however, what is the point of buying a car that someone cannot repair and maintain? In fact, the E46 is already quite an old car and the costs of maintaining it at a reasonable level (decent replacements or original parts) will not be low.
  • Helpful post
    #3 17021247
    melas
    Level 31  
    I have such an engine for 204 thousand parts, the valvetronik ran without a problem.
  • #4 17023394
    wowka
    Level 28  
    SQ9MEM wrote:
    The truth is that an engine with a damaged Valvetronic will never run properly


    Maybe it's true, but after a test drive of about 15 km, I can say that it is not bad at all, the gearbox works well and the ECU reports only one error (unplugged engine controlling the shaft). I don't care that much about power, just what is.

    SQ9MEM wrote:
    Burning will be greater
    From what I found on the forums, it grows by about 0.5-1 l / 100km, so there is no tragedy.

    SQ9MEM wrote:
    I do not understand, however, what is the point of buying a car that someone cannot repair and maintain?


    How do you know if I can afford it or not? I am not one of those who will charge money at any cost and waste time fixing things that give practically little profit. It would be different if you could buy a new repair kit in reasonable money, and since the factory defect means few spare parts, they are expensive, and what is worse, it is very difficult to judge the wear and tear on the Internet, and after replacement it may turn out to improve there is little or no.
    Of course, if I can get the shaft and levers in reasonable money, I will risk a replacement, but it must be a reasonable amount. Used engines are not very expensive so you can risk killing what is.

    If it had not been for the fact that the car is in perfect technical condition, I would not have bought it, and on the other hand, if it had not been for this engine defect, the German would not have sold it - so the balance in nature is preserved :)

    SQ9MEM wrote:
    In fact, the E46 is already quite an old car and the costs of maintaining it at a reasonable level (decent replacements or original parts) will not be low.



    When any bigger problems start, I will sell it to some youngster, let him drive his sticks to discos and worry about repairs. It looks nice, and most people buy the look, not the condition.
  • #5 17023612
    Strumien swiadomosci swia
    Level 43  
    wowka wrote:
    However, I have no comparison, because it is "fresh" imported from abroad.

    - Are there large differences in engine dynamics with and without a working valvetronic system?
    - Are there differences in combustion?
    - How will it work with an automatic transmission?
    - What are the other side effects of driving with Valvetronic not working?


    Take it up .... cut it before you come up with the idea of registering in Poland.
    Repair of valvetronika is non-profit, a few thousand PLN have to be spent if the head is operational.
    A side effect of blocking valvetronics is vanos failure.

    Overall, the engine is worth it, as I already transplant to the R6.
  • ADVERTISEMENT
  • #6 17023632
    SQ9MEM
    Level 29  
    Well, that's why I know that if you could afford it, you would buy a car with a working engine, and you wouldn't think about a sculpture with a current one. This is not a radio CD issue, and you know it. Unfortunately, this is a typical problem in Poland with premium segment cars - you buy a brand (for example, Audi, Mercedes, BMW, although there are others) and then the combinations start to save on everything. And the difference is by no means small. A slight, imperceptible difference is 5%. 20% will give you a noticeable difference. I have a comparison because I had the opportunity to drive with a damaged Valvetronic and repaired.
  • ADVERTISEMENT
  • #7 17023636
    Strumien swiadomosci swia
    Level 43  
    SQ9MEM wrote:
    Well, that's how I know that if you could afford it, you would buy a car with a working engine

    Yes, only if you buy this scab in DE, you pay 300E plus transport. These are the realities.
  • #8 17023656
    SQ9MEM
    Level 29  
    This is the highlight of the program. The German is aware of how much the repair will cost; The Pole will be trying to make forks. I will write again - you have no money for an expensive repair kit - buy a car with an efficient, cheaper engine. I know that this is a strong off-topic, but I will mention such a situation - my friend generally deals with Car-Audio, about a year ago he received a call (I witnessed this situation) from the owner of the old Astra (born in 1994) asking about the installation of the radio. There was no power supply, speaker or antenna installation in the car. A colleague explained to the client how much work it would take and valued everything (cables + speakers) at PLN 250. The client's wife interrupted and said "but it must be cheaper because we are poor". The hands drop.
  • #9 17023886
    Strumien swiadomosci swia
    Level 43  
    SQ9MEM wrote:
    The Pole will be trying to make forks

    But it's not about cash, because even if you put it out, it will still be a ticking surprise, about a piggy bank on wheels.
    It's just that the engine cannot be repaired for long.
  • #10 17024925
    wowka
    Level 28  
    Strumien swiadomosci swia wrote:
    Take it up .... cut it before you come up with the idea of registering in Poland.


    Unfortunately, it is too late for such a decision :)

    Strumien swiadomosci swia wrote:
    Overall, the engine is worth it, as I already transplant to the R6.


    This car is worth too little and too much trouble for me to want to sculpt with swaps.

    SQ9MEM wrote:
    Well, that's how I know that if you could afford it, you would buy a car with a working engine


    I already have such a car, but I could use a second one and here was an opportunity.

    Strumien swiadomosci swia wrote:
    Yes, only if you buy this scab in DE, you pay 300E plus transport. These are the realities.

    Strumien swiadomosci swia wrote:
    But it's not about cash, because even if you put it out, it will still be a ticking surprise, about a piggy bank on wheels.
    It's just that the engine cannot be repaired for long.


    And here is the answer to the question why this post was even made :) , I'll tell you that you didn't make a mistake about the price :)

    But the engine has the "advantage" that it works quite decently with a damaged valvetronic, so such a "piggy bank" can be easily sold, because hardly anyone knows about it (until recently I had no idea about it either).
    It is worse when the engine has a defect such as the rotating bushings - the repair is totally unprofitable, the cheapest engine used is PLN 4,000, and when the engine is not working, no one wants to buy a car - then the problem begins. (famous Dci from Renault and BXE - Vag TDI)
  • #11 17025071
    Strumien swiadomosci swia
    Level 43  
    wowka wrote:
    because hardly anyone knows about it


    So what you have to be brainless when buying a car with a stick, but well, most buyers of these scabs have a budget for a seicento and unfortunately they do not fuss when they want to have a BMW.
  • #12 17025605
    Arton
    Level 16  
    The neighbor has an E46 with this engine. He has already put on about 4,000 and the car does not run as it should. I'm also slowly starting to look for these three and I'm afraid to go and watch. But the engine is rather m43b19. I had two of them, each I made about 50,000. km. And I praise myself. Valvetronic is out.
  • #13 17026320
    helmud7543
    Level 43  
    I think my colleague was interested in whether it would fall apart completely when he would drive like this. I am curious myself (I have m43 so that I don't want to sculpt).
  • #14 17026476
    Strumien swiadomosci swia
    Level 43  
    helmud7543 wrote:
    I think my colleague was interested in whether it would fall apart completely when he would drive like this. I am curious myself (I have m43 so that I don't want to sculpt).


    But there's nothing you do to ride until it crashes and insert the m43 at cost.
    It is foolish to invest in an engine n ......
  • #15 21248267
    psycode
    Level 17  
    wowka wrote:
    [But the engine has the "advantage" of running quite decently with a faulty valvetronic....


    It's been over 4 years, but I couldn't find anyone else on the forums who was going to drive with the valvetronic off for long.

    I've probably got the same thing: shaft and cams to be replaced - as today it wouldn't start, check engine blinking, 2,3,4 cylinder ignition loss. So much so, I've had the car for a month - bought impulsively. After buying it I discovered the chassis was rotting at the back, dual mass and clutch to be replaced, shaft support, brakes to be done, manual. And now a couple of grand for cams and a couple of grand for a shaft + work? It's getting to be a bottomless pit - not sure what decision I'm going to make yet.

    That's why this topic is important to me - to have confirmation from someone who has driven without valvetronic for a long time whether anything bad happened afterwards.
  • ADVERTISEMENT
  • #16 21248691
    Strumien swiadomosci swia
    Level 43  
    Nothing happens.... But sell that scab.
  • #17 21451159
    126756171
    Level 1  
    For anyone wondering if it is possible to drive the N42 without Valvetronic - YES. Having an automatic transmission, you need to unplug 1 plug from the VANOS solenoid valve. The car will start hard and for half a minute (summer) to 3 minutes restarting (winter) it will run like a tractor and shake all over. Then the check engine flashes and magically starts working normally. The combustion is slightly higher. I have been driving like this for over a year :) .

    I tried unplugging other plugs. It would start normally, but the transmission would go into emergency mode.

    There is a professional in Pomerania who can supposedly blow the Valvetronic out of the engine and go to throttle, just looking at the value of the debris, not sure if it's worth it as such a service is about £2k.
  • #18 21453120
    Strumien swiadomosci swia
    Level 43  
    2,000zł for this model is like splunąć...... bmw is costs always and not small.
  • #19 21738954
    bialyperelka
    Level 11  
    I've had a couple of cars tested and they've been running for a couple of years now without valvetronic and all ok - better than before, because there were problems before. You just have to know how to unplug it and set it up.... Errors only after connecting the computer, on the dashboard ok.
Reply | New topic
Report a violation of the law

Topic summary

✨ The discussion focuses on the BMW E46 Compact with the N42 1.8L 116KM engine and automatic transmission experiencing a common Valvetronic eccentric shaft wear issue. This defect causes heavy fuel consumption, poor running of the 4th cylinder at idle, and frequent stalling. Disconnecting the Valvetronic shaft position sensor or actuator motor forces the system to maximum valve lift, effectively disabling Valvetronic, which allows the engine to run reasonably well despite increased fuel consumption (approximately 0.5-1 l/100km higher). Users report noticeable differences in engine dynamics and combustion quality with a damaged or disabled Valvetronic system, including rough idling and increased emissions. The automatic transmission generally functions normally when Valvetronic is disabled, provided the VANOS solenoid valve plug is also disconnected to avoid transmission emergency mode. Repairing the Valvetronic system is costly and complex due to expensive and scarce parts (shaft, cams, levers), with repair costs reaching several thousand PLN or GBP, often making replacement engines a more economical option. Some users have driven long-term without Valvetronic, noting no immediate catastrophic damage but acknowledging the engine is a "ticking time bomb." There is mention of a professional service to disable Valvetronic permanently by removing its components and switching to throttle control, costing around £2,000. The consensus advises caution when purchasing vehicles with known Valvetronic defects due to high maintenance costs and potential reliability issues.
Generated by the language model.

FAQ

TL;DR: 12+ months driving an N42 with Valvetronic off; "The combustion is slightly higher." Expect 30–180 s rough starts, then normal. For automatics, unplug one VANOS solenoid; full Valvetronic delete coding ≈ 2,000 zł. [Elektroda, 126756171, post #21451159]

Why it matters: This FAQ helps BMW E46 N42 owners decide between fixing Valvetronic, coding it out, or safely running disabled when budgets are tight.

Quick Facts

Can I drive my BMW E46 N42 with Valvetronic disabled?

Yes. One owner reports over a year of driving with Valvetronic off on an automatic. Starts are rough for 30–180 seconds, then it runs normally. Fuel use is slightly higher. Use the VANOS-solenoid unplug method on automatics. Unplugging other connectors can force gearbox emergency mode. Treat this as a workaround, not a repair. [Elektroda, 126756171, post #21451159]

How do I disable Valvetronic on an N42 automatic without triggering limp mode?

Use this reported method:
  1. Unplug one VANOS solenoid connector.
  2. Start the engine; expect 30–180 seconds of rough idle and a flashing check engine.
  3. Once it stabilizes, drive normally; do not unplug other connectors or the gearbox can enter emergency mode. [Elektroda, 126756171, post #21451159]

What start-up behavior should I expect after disabling Valvetronic?

Expect hard starting, tractor-like running, and shaking immediately after start. In summer this lasts around 30 seconds. In winter it can last up to three minutes. The check engine will flash, then the engine smooths out and drives normally. [Elektroda, 126756171, post #21451159]

How much does fuel consumption increase with Valvetronic off?

Reported increase is about 0.5–1.0 l/100 km. This aligns with users who note only a slight rise in fuel use when running on fixed maximum valve lift rather than active Valvetronic control. [Elektroda, wowka, post #17023394]

Will performance drop without Valvetronic, and by how much?

Yes, the drop is noticeable. A member with back-to-back experience notes, "20% will give you a noticeable difference," while 5% feels slight. Expect reduced throttle response and overall dynamics without Valvetronic’s variable lift benefits. [Elektroda, SQ9MEM, post #17023632]

Can disabling Valvetronic damage the VANOS system?

There is a reported risk. As one expert warns, "A side effect of blocking valvetronics is vanos failure." Treat long-term operation in this mode as compromise-only and monitor for timing or cam phasing faults. [Elektroda, Strumien swiadomosci swia, post #17023612]

Will the automatic transmission still shift normally with Valvetronic off?

Yes, if you unplug one VANOS solenoid connector as described. The car may start rough, then run normally. Unplugging other connectors made the transmission enter emergency mode for one owner. Stick to the single VANOS connector method. [Elektroda, 126756171, post #21451159]

Can a tuner code out Valvetronic and revert to throttle control?

Yes. A specialist can disable Valvetronic in software and run conventional throttle control. Reported price is about 2,000 zł. Consider this against the car’s value and overall condition before committing. [Elektroda, 126756171, post #21451159]

Is repairing Valvetronic worth it on an E46 N42?

Many call it uneconomical. “Repair of valvetronika is non-profit, a few thousand PLN have to be spent if the head is operational.” Some advise considering an R6 swap instead if you plan to invest. [Elektroda, Strumien swiadomosci swia, post #17023612]

Does Valvetronic failure always correlate with high mileage?

Not necessarily. One owner’s engine ran its Valvetronic without issue at 204,000 km. Wear varies by maintenance history and usage. Mileage alone does not guarantee failure or reliability. [Elektroda, melas, post #17021247]

Will the engine eventually fall apart if I keep driving like this?

A veteran member responded, "Nothing happens.... But sell that scab." This reflects a view that continued running is possible, yet the car may remain a money pit. Plan an exit or repair strategy. [Elektroda, Strumien swiadomosci swia, post #21248691]

Are used replacement engines a smarter bet than rebuilding Valvetronic?

Some owners prefer running the failing unit and swapping later, noting used engines aren’t very expensive. This can be cheaper than chasing Valvetronic parts and labor with uncertain outcomes. Assess local engine prices before deciding. [Elektroda, wowka, post #17023394]

Which parts usually fail when Valvetronic acts up on the N42?

Common culprits include the Valvetronic eccentric shaft and its levers. Symptoms include heavy fuel burn and a dead cylinder at idle. Unplugging the position sensor or motor forces maximum valve lift, effectively disabling Valvetronic. [Elektroda, wowka, post #17020667]

What faults point to Valvetronic wear, like misfires?

Reported signs include a blinking check engine and ignition loss on cylinders 2, 3, and 4. In such cases, diagnosis shows eccentric shaft and cam wear, implying costly parts and labor if you repair. [Elektroda, psycode, post #21248267]
Generated by the language model.
ADVERTISEMENT