RPM Pause at high RPM / WOT.

Solberg

Registered User
When WOT car is running fine till around 5000 rpm, then the rpm "pauses" and I can hear clicking/small bangs from the engine, I do NOT loose my boost pressure when this happens, but I loose engine power because the RPM just stalls, so I have to get off throttle.

Have had this problem for some time now and been discussed here before but changed following parts to brand new genuine:

MAF sensor
MAP sensor
Lambda sensor
All coils
All plugs to bkr7e gapped 0,028
Start battery


Scanned in VCDS today:

6 Faults Found:
17956 - Boost Pressure Regulation Valve (N75)
P1548 - 35-00 - Open Circuit
17931 - Crash Signal from Airbag Controller
P1523 - 35-00 - Implausible Signal
17695 - Boost Pressure Control Valve (N249)
P1287 - 35-00 - Open Circuit
17746 - Camshaft Position Sensor (G40)
P1338 - 35-10 - Open or Short to Plus - Intermittent
16885 - Vehicle Speed Sensor
P0501 - 35-10 - Implausible Signal - Intermittent
18010 - Power Supply Terminal 30
P1602 - 35-10 - Voltage too Low - Intermittent
Readiness: 0000 0000


n249 is wires ****** which i know about.
Battery is because ive installed a new one.
Speedsensor i know because speedo is not working when car is cold.


Camshaft sensor i dunno.
n75 valve i also dunno as car is boosting just fine.


Car feels abit down on power tho!!!!

Reseted codes, took a drive and this was the only codes (car was still "missfiring")
3 Faults Found:
17931 - Crash Signal from Airbag Controller
P1523 - 35-00 - Implausible Signal
17956 - Boost Pressure Regulation Valve (N75)
P1548 - 35-00 - Open Circuit
17695 - Boost Pressure Control Valve (N249)
P1287 - 35-00 - Open Circuit
Readiness: 0000 0000
 

Stuart B

Registered User
its so difficult with these cars isn't it? so many bits changed at once and never know if one of them is to blame for the next problem :|
 

Solberg

Registered User
Just discovered that my valve cover is missing one nut, but i dont belive that it could cause such total power loss and bang sounds from engine on high rpm? Ive not been able to reach redline one single time since october i think, ****.

Pic from last year when i got the car
Skjermbilde 2017-03-28 kl. 21.31.35.png


Taken today
Skjermbilde 2017-03-28 kl. 21.31.23.png
 

Solberg

Registered User
is the banging the pre-detonation?

Yeah thats what I think, that the banging is fuel igniting at the wrong time which is stopping up the crank causing RPM to pause. (trying to think logical)

Or from all I know it could be valves etc kissing the pistons, because the bang could be the sound of fuel ingition or it could be metal to metal hard to tell.
 

Solberg

Registered User
Could the sound of banging/clicking just as much be related to the clutch or flywheel some crazy way?

Edit: I forgot I get "detonation/missfire/clicking/banging" or whatever when standing still in neutral aswell.
 
Last edited:

Stuart B

Registered User
I didn't say it would? I asked if he had already changed his fuel pump as couldn't remember from last year - when we both had similar issues.
 

Solberg

Registered User
crank sensor.................. if loosing position/signal momentarily will result in a bang

Hmm will look into it. Car is starting fine tho, but will see if its loose or anything.


If I change N75 to a different type, will it need to "adapt" or be driven in before it start to work proper, or will it work the right way after i plug it in?
 

Solberg

Registered User
What about timing, if the timing belt have slipped how can I verify this exact? This seems to be my last logical solution to this madness.
 

Solberg

Registered User
What abou VSS sensor, my speedo only work after driving for say 15-20mins, before that it is either jumping around or compl dead. Could VSS relate to not beeing able to rev high? Happens in neutral too tho.

Sent fra min PLK-L01 via Tapatalk
 

Solberg

Registered User
Not anyone else who have had this problem? Not being able to rev past around 5000 rpm?

I need to fix this asap so I can sell it, never buying a Vag product again worst **** ever made.
 

Solberg

Registered User
crank sensor.................. if loosing position/signal momentarily will result in a bang

You sir, are a living legend! HUGE THANKS BILL :) Cranksensor had become slightly loose as you foresaw.

Because of you I know can pull my S3 beyond 5000 rpm, and it is also pulling alot harder from bottom line and on "high" gears. Have had this issue since the start of october 2016 i reckon, wow!


PS forget my last post, I love my S3 again :yahoo:
 
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