[1.2 TDI ANY] hydraulic oil pump constantly running

[Germantas]

Sorry that I am writing in English. Like all of you my Audi a2 1.2 tdi have a problem with gears shifting. I spend a lot of time to read all problem related forums but didn’t find solution. My A2 hydraulic   pump was running all the time, and I decided to change an accumulator tank. I bought new one Febi (with adaptor) and use one with a pump from my friend (5-6 gear changes before starts pump). Clutch disengaged at 1.84v and engaging 3.85. Did basics adjustments. Problem: pump is running constantly when engine is on. Car starts in S and N but won’t run. When I change to D or R car engine is revving but not drive because clutch is ON. VCDS group 3 showing Clutch position (Actual) 99.6% and Clutch position (specified) just running in a circle from 2% to 75% and back. Some time, when I start a car in N and then to D is disengage clutch and it drives and changes gears, but pump is running constantly. There is no leakage in a system. I on the way to buy a new clutch cylinder, but not sure it will help, and is not so cheap just to buy it and try. Can someone have advice?

There is video from VCDS: 

 

[Lupo_3L]

You say pump is running constantly. Question number 1.: Is there enough hydraulic fluid in the system?

The pump should definitely not run constantly. Even with a bad pressure accumulator it would not constantly run.

[Germantas]

Hydraulic fluid I changed to new and level is correct. When I open a door ,pump is running for maybe 30 sec, then stops until I start engine. Then will run again 30sec. Will stay until press a brake or trying to change a gear. When test run a car, I hear that pump is run constantly, because clutch is engaging and disengaging and  gears is changing. Sounds like accumulator tank is bad, but it is totally new and even tried with use one who works perfectly on another car.

[Eumeltier]

Your video don't show the value of the clutch cylinder (G162). As the clutch position is shown at ~100%, the voltage value for G162 should be constant near 4V. Is this correct?

 

But you write:
 

vor einer Stunde schrieb Germantas:

clutch is engaging and disengaging and  gears is changing.

Because if the clutch cylinder would be active engaging and disengaging all the time, the constantly running pump would be understandable. But the 100% value would say that the clutch is and stays open the whole time.

 

Your video, is it in D or N? Does anything change if the motor is not running?

[Germantas]

VCDS show 99.6% and voltage is if i remember correctly 3.85v. I did video when engine is running, and gear shifter is in D. When I am starting a car in S position, then go to N and D, engine just revving buy car not driving (my video did in this stage). But, when starting engine in N and then to D, not always but often, clutch is disengaging, and I can drive. I didn't check how is when engine not runs. Will do it today. What more i can try or read with VCDS to be shure there is a problem?  

[Eumeltier]

I would check following situations:

 

Motor off, N
Motor off, D

Motor off, D, brake pedal pressed

Motor on, N
Motor on, D

Motor on, D, brake pedal pressed

 

What happens in each situation with the G162 value and the both clutch position values?

[Germantas]

I made a video where i showing what is happening with a gearbox:

 

[Eumeltier]

There are some strange readings.

 

If you are in N, the clutch should be pulled. And regarding to your readings, it is.
But the target value (clutch position specified) is changing. As it should close.
In N it should never close.
So first - why is the control unit wanting to close the clutch? And furthermore, why is the clutch not closed, if the control units wants to? (even if it is not correct to close the clutch in N...)

 

You have not filmed the instrument cluster the whole time. I remarked when you selected D, there was no gear shown in the display.
What happens if you change the lever to the left - tiptronic? Are the numbers 1 to 5 shown?
If you do this with motor stopped, you should also be able to change the selected gear with + and -

Did you try to do the basic setting?

[Germantas]

"So first - why is the control unit wanting to close the clutch?" 

Gearbox in D and no brakes. Clutch need to be closed and car need to drive. This is my understanding. Sorry for video,i not made it to show all. But mostly i will show that car engine starts in S or N, but when switching to D or R clutch still open and car can not drive. And pump os constantly running. 

[Eumeltier]

No no,

at 5:06 you are in N and the "Clutch position (specified)" is going down to 0.2%, so the control unit says the clutch should be closed.

 

In N the clutch should be open. And regarding to G162 and "Clutch position (actual)" it IS open. But the control unit says "close".

 

So, why does the control unit wants to close the clutch in N? And if the control unit wants this (even if it's wrong), why is the clutch not closed?

 

 

There is something total mixed up.

 

Did you tried the basic setting?
https://wiki.a2-freun.de/wiki/index.php/Getriebegrundeinstellung

 

Edit: I think this discussion should get it's own thread. Maybe an admin can move it?

Bearbeitet vor 16 Stunden von Eumeltier

[Germantas]

You are totally right! Spend lot of time to read English and German forum about gearbox  problems and solutions. Wrote to this forum because i'm confused and can't find a answer what is it. For example, yesterday i just started engine and test drive s car without a problem. Just pump was running constantly. Then i decided to drive a car to a garage and got this problem some was from las weekend when i change accumulator tank ang fluid. From my video you see, when car is in D snd brake is released clutch specific values is moving up and down, but actual is always showing 99.6 %, it's mean clutch is open. Why...?

[Germantas]

I already contacted Mankmil for new clutch valve,and he wrote that it need to be changed by age and millage. But want to understand if it helps

[Eumeltier]

At this moment I don't see the evidence that the clutch valve is the problem.

 

The clutch valve needs the hydraulic pressure to OPEN. But it is open. All the time.

 

Did you see the clutch closed with VCDS? If you just turn the ignition on with the lever on STOP and no break pedal pressed, is the G162 below 2V?

 

If the clutch is still open, disconnect the electric plug at the hydraulic block and release the accumulator tank 1/4 turn. Then all hydraulic pressure is gone and the pump won't work anymore. At this moment the clutch must be closed.

If it is still opened without hydraulic pressure, I assume a mechanic defect with the clutch itself. Then the new clutch valvue won't help at all.

 

So I think at first you have to be sure about the reason for the problems before changing any parts.

[Germantas]

Yes,i see clutch is closing some times. But you are right, maybe is some mechanical problem and is stuck and some time just release. Now is dark, will try to do the same test, but will try to move by hand a clutch lever. And, if i have this situation, it's mean clutch leaver need to be pulled ans stuck,but clutch valve  cable need to be pulled off?

Bearbeitet vor 15 Stunden von Germantas

[Eumeltier]

If your clutch won't close and you want to exclude that it is because the hydraulic system gone wild for some reason, you have to release all pressure.

 

https://wiki.a2-freun.de/wiki/index.php/Getriebegrundeinstellung#System_drucklos_machen

 

I don't know if you can read any german?

- Loose the coolant tank and put it aside

- Remove the black electric plug at the hydraulic pump. So the pump won't work anymore
- Loose the hydraulic accumulator tank by 1/2 turn. So the pressure is released, all hydraulic oil will go back into the reservoir

 

After this the clutch has to be closed, because there is no more hydraulic pressure left.

 

If the clutch is not closed, then you have a mechanical problem.

 

Don't forget to tighten the accumulator tank before connecting the pump again, otherwise the oil will spill...

[Germantas]

I know how to do this. I did it more than 10 times. Will do this tomorrow one more time. Funny, i learned a German in school. But it was 30 year ago. And if you not using it  in your life, you forgetting it. 

I have 5 pcs. Audi A2. Two is 1.4i,two is BCB( did swap). I decided to buy 1.2tdi and didn't imagine that it will be so complicated:)

 

Bearbeitet vor 14 Stunden von Germantas

[_Manni_]

Maybe you start your one thread with information, instead of posting in the KNZ hall sensor repair thread.

 

Only a hint  

[Germantas]

8 hours ago, _Manni_ said:

Maybe you start your one thread with information, instead of posting in the KNZ hall sensor repair thread.

 

Only a hint  

I will happy to do this, but i'm not German and don't know how are people reacts when i writing in not forum native language. I can use a google translate, but can't be shure if it translate correctly

[Eumeltier]

There is the special english sub-forum:

 

https://a2-freun.de/forum/forums/forum/57-english-language-forum/

[_Manni_]

vor 1 Stunde schrieb Germantas:

vor 10 Stunden schrieb _Manni_:

 

I will happy to do this, but i'm not German and don't know how are people reacts when i writing in not forum native language. I can use a google translate, but can't be shure if it translate correctly

 

You dont need a german passport to start a thread here  

 

And you see... We try to speak english with you without a problem.

 

[DerWeißeA2]

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