MK5 Golf GTI
All Things Mk5 => How to Guides / Troubleshooting => Topic started by: Dannyboy88 on January 23, 2013, 02:00:19 pm
-
Just wondering if anyone could shine any light on the problem I seem to be having, when I've been out in the car I always let it idle for a minute or so then turn off the engine, but lately I've notice the engine makes abit of a noise when I turn it off, ill try and get a video of this happening and post up the link, I was just wondering if it could be EGR or anti shudder valve related? The car is on 76k and serviced every 10k using genuine parts. Any help would be great.
-
Is it smooth or juddery when you kill the ignition?
I had to change the inlet manifold flap motor (anti shudder) on my tdi last year, it was a bit bumpy on shutdown as the flap was stuck open.
Easy to check, just a few allen bolts and you can manually test it.
Video would be useful if it is different to this :happy2:
-
As Skard said, it's not a bad job to remove and clean. At 76k I would say its well due one. Is it a new noise or one you have just started to pay attention to that may have already been there?
When you turn the ignition off the ASV closes to stop anymore air from entering the engine (preventing overrun/run off). When its doing this is make a high pitched electronic whistle and after a few seconds after the engine has stopped it will click which is it opening again.
Here was my ASV after just 20K.
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fimg.photobucket.com%2Falbums%2F1003%2FMatt.H%2FInternet%2FIMAG0158.jpg&hash=9a0badb07ead68583bb0c7d28987bbe706597aad)
-
I'd say its one that I've just started paying attention too, i'll get a video when I'm home from work and post it up, thanks again guys much appreciated.
-
Here's a quick video, I know the alternator tensioner sounds abit noisey but its the noise when I shut off the engine.
-
I'd say it's the ASV as it's very jerky - if you get a flathead screwdriver and prise off the clip, remove the hose going into it and carry out the same procedure - have a look to see if the valve temporarily closes on ignition kill, if it sticks open or doesn't fully close then you'll know for sure.
If you do need one, I got it from Euro Car Parts using a discount code, it's the same one as the dealer provides but half the price.
-
I've just taken another video after my drive home so the engine is up to temp as the first video is from cold, but it does seem to make the engine jerk when I shut it off, ill try what you've said about and see what the result is, ill upload the 2nd video now.
-
Here's the second video, what I'm trying to show is that when I shut off the engine the engine jerks and it sounds rough if you know what I mean lol.
-
My opinion is still the same, you might need a small mirror to check the valve function.
-
I've got a mate who works in a motor factors so can get me a new ASV at cost so he's going to price it me tomorrow, but ill still check if the flap is staying open when I shut the end off.
Skard, is this what your car was doing before you changed your ASV?
-
There's going to be an element of 'jerkyness' when shutting off any engine but yeh that was similar to mine. Upon inspection my flap was stuck open.
I'd definitely check the operation before ordering a new one.
-
Ok no problem, thanks for the help, so if the flap isn't fully closing when the engine is turned off it needs replacing? If it isn't the ASV I'm not sure where to start looking.
-
Common fault:- the gears strip internally and give your fault before failing totally.
found this article below which may help?
Since the ASV is an all or nothing unit (either open or closed), there is really no scenario where the unit should ever remain in a mid position.
You'll find four wires going to the device. Two for motor power and two to a position sensor. Spring tension will hold the valve normally open. Engine shutdown will apply voltage to activate the ASV motor, the valve shutter will cycle, and a flag will pass the sensor in order to signal to the ECU that the function has taken place... At least that's the way it should be.
If there is voltage to the motor and a ground path, you may expect the motor to cycle. If a high resistance path, then likely a partial cycle until such point as the motor is unable to overcome the homing spring.
Of course the sensor wires could also be a problem. If one or the other was crushed and partially shorted or open, then the ECU would receive spurious information and attempt to cycle the ASV based on false information.
My guess here is the ASV motor. Short of an obvious broken or shorted wire in the harness I expect the new unit will work as advertised.
-
When your ASV caused problems did it bring any lights on or make any noise or was it just abit jerky when shutting the engine off?
-
I had no lights appear nor a VCDS fault log.
The problem was smashed cogs.
-
Ok mine doesnt really make a noise or anything but just with the engine being jerky on shut off its pointing me towards the ASV, ill get my friend with VCDS to scan it at the weekend and all also do afew tests on it, just been quoted £107 for a pierburg ASV from my friends work.
-
It takes a few minutes to check if it's sticking, I doubt a scan would point to it as electrically it'll be fine...prise off the clip, remove hose, have a friend start/stop the engine and keep an eye out, might need a small mirror for visibility.
-
Ok thanks Skard, ill let you know my findings, whilst I'm under the bonnet I'm going to change the alternator tensioner and belt.
-
You might find it's your alternator clutch pulley that's making it sound a but rickety, if either of those changes make no improvement on the noise.
-
Just a question about the tensioner, does if flap about like its lost its tension?
-
There is movement in the tensioner but nothing out of the world the belt still looks tight, I just thought the noise sounded like it could be the tensioner or am I wrong? :laugh: lol
-
Yes it could still be the tensioner but when I went down a similar route with my mk4 (tensioner was flapping about, especially with the engine under load like when on full lock for example) I replaced the tensioner thinking it was that. Changed it and all was good for about a day haha. So did some research which pointed to the alternator pulley. They have a freewheel clutch mechanism in them, which dampens the ocillations of the engine. When these seize up, it causes the tensioner to waggle as the belt is speeding up and slowing down (exaggerated).
You can test by taking the tension off the belt, slide an Allen key or small screwdriver through the hole in the tensioner which holds it back, slip the belt off the alternator pulley, then with your hand spin the pulley without letting go and jerk it back the opposite way. You should be able to make it freewheel. I suggest wearing gloves if you do try it so the ribs on the pulley don't slice your hand if it spins.
-
Agree the alternator pulley can give a false reading of a failing tensioner.
Had a tickover rumble on two previous diesels because of this.
If you're changing it, a tool like http://www.ebay.co.uk/itm/Laser-3307-Alternator-Tool-M10-Spline-1-2-D-/280964948511?pt=UK_Hand_Tools_Equipment&hash=item416ad0e21f will be handy
-
Usefull info there chaps. I'm going to take my asv off and have a spring clean me thinks.