Intake valve not closing long enough, causing engine shake!

Hi, my engine has been shaking a bit more than usual when I turn it off lately.
The intake valve should close for 3 seconds.
"...for me, it's about 0.5 seconds when turning off the engine... that's too short!!"


I performed an actuator diagnosis, and the solenoid valve for the throttle seems to be okay, or at least it's making a sound when it switches, but I'm not sure if it's working correctly.

What else could I check?



[img=http://srv010.%=srvName %>/20071002194139410_hpgiqurqvg.jpg]

[img=http://srv007.%=srvName %>/20071002194509409_eznodrqnkl.jpg]


I just compared it to a TDI ALH engine from a friend's car, and in that case, the valve closes for exactly 3 seconds...


Where could the error be?



Sven.[/img][/img]

.... no one knows a solution .


Sven.

Perhaps there's a leak in the vacuum supply line to the control valve?

Hi,

Perhaps there's a general leak in the vacuum system? In my case, the plastic hose to the brake booster was brittle (I can't understand how they could install such poor quality parts), which caused the vacuum to bleed off very quickly when the engine was turned off.

You can easily test this: Turn off the engine, wait ten seconds, and press the brake pedal. If the pedal is rock hard, then you have lost a significant amount of vacuum pressure. With a functioning system, there should still be enough vacuum pressure left even the next day so that you can at least press the brake pedal with power assist once or twice (with the engine off).

You can easily spot major leaks... have someone turn off the engine while you stand next to it. A hissing sound will reveal the source of the leak.

Best regards,

Jan.

Thanks everyone, I'll check the car and those points tomorrow.
"Every morning, I notice that the brake pedal feels very hard. I'm going to check it out."


Sven.

Hi,

Quote:

"Every morning, I notice that the brake pedal feels very hard. I'm going to check it out."

Well then... that's almost certainly the case.

Take a look at the thick black hose that goes into the brake booster...

Best regards,

Jan.

... I just came back from the car; it had been parked overnight, and the brake pedal is completely stiff.
I then disconnected the hose from the N 236 that goes to the throttle valve and tried to create a vacuum by mouth first, then with a syringe, to see if the valve would move.
... luckily, it moved about 2-3 millimeters, but I couldn't maintain the vacuum pressure.

I removed the pressure sensor and opened it up, and I saw a crack, about 2 centimeters long, in the rubber membrane.

Once I get my camera back, I'll take a picture.

Bug fixed, user happy .


" color="red">Bitte keine Links zu externen Dateihostern! a) nerven die zusätzlich notwendigen Klicks, b) Wartezeit, Werbebanner/Werbepopups und notwendige Registrierungen, c) ist nach einiger Zeit die Datei weg und das Thema für andere Leser nutzlos!

Bitte nutze 'Attachment hinzufügen' bzw. das Upload Forum hier.