My Scirocco shakes when idle

[Packham93]

Hello,

I am looking for abit of advice.

My Scirocco has been shaking when idle for about a year now, some days its really bad and some days its non existent.

I have taken my car to 4 different mechanics (Including VW main dealer) and they all said it was the dual mass flywheel, I got a new DMF put on it last weekend and the shaking is still there. I also was told it could be the fuel injectors so I took my car to a specialist place which deals with this type of thing and they checked all injectors and clean them up and put new heads on them and told me all injectors were fine.

I have had 2 lots of diagnostics on it and nothing shows up, I have also had a new timing belt put on it in the last month from VW

I have now spent thousands trying to get this issue sorted however no one can figure out whats causing this. Please could someone help?

[Cuprabob]

Is the idle speed stable or jumping about?
Does it sound as if it's misfiring?
Have the engine mounts been checked?

[Packham93]

Is the idle speed stable or jumping about?
Does it sound as if it's misfiring?
Have the engine mounts been checked?

Thanks for the reply.

How do you mean by is the idle speed stable?

The engine just doesn't sound like its smooth at all when idle, I know very little about cars so wouldn't know if it sounded like it was misfiring however when the car is idle and its shaking sometime it sounds like the engine is going to cut out it never does but it sounds like its going to. I am not sure if the mechanics have checked the engine mounts.... however when I lift the bonnet up the engine looks like it moves a fair bit and it just doesn't look or sound healthy at times....

[Cuprabob]

If you look at the rev counter when the engine is at idle is the needle steady or does it fluctuate up and down.

I assume you have a diesel from changing the belt comment. My diesel idles at around 750rpm and is steady. What value is yours idling at?

Has the car been scanned for any fault codes?

[Packham93]

Yes the car has been scanned and nothing has come up, yes I do have a diesel. In terms of the rev counter I did notice the other day it was sitting at 1000rpm however that was when it was cold, I have just checked and its now sitting at 750rpm

[Cuprabob]

Yes, it idles higher when it is cold. Does it still shake when the idle is higher at around 1,000rpm?

When it's idling at 750rpm, is the rev counter steady and stable at 750rpm or is it fluctuating?

[Kruder]

It could b faulty valves. My car was vibrating a whole lot more during idle and RPM was fluctuating while accelerating which resulted in jerky motions. Went to VW to get it replaced and all's good now


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[a4gee]

Interesting post this as my 2009 petrol 2.0 tsi has done the same thing recently. I`ve noticed it when coming to a stop. Engine has been hot and not for it to happen.
When your sitting minding your own business, it suddenly feels more like a tremor. It lasts for maybe 10-15 seconds then all is ok. It`s only happened in the last month and not all the time either.

[Packham93]

Yes, it idles higher when it is cold. Does it still shake when the idle is higher at around 1,000rpm?

When it's idling at 750rpm, is the rev counter steady and stable at 750rpm or is it fluctuating?

When I up the revs when idle the shaking does go away, sometimes if I have people in my car and I'm at a red light I up the rev to about 1500rpm to make the shaking go away to stop people noticing it.

[tSeL]

First go and check cylinder compression.If nothing is wrong check your sparkplugs mileage


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[Cuprabob]

....check your sparkplugs mileage

Could prove difficult...it's a diesel

[tSeL]

Easier than spending all this money without being sure on where the problem actually is


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[Cuprabob]

Easier than spending all this money without being sure on where the problem actually is


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You do realise that diesels don't have spark plugs?

[tSeL]

Thought you were talking about compression procedure,excuse me


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[Cuprabob]

Thought you were talking about compression procedure,excuse me


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Not at all...compression test is a good call.

[Rawcpoppa]

Have you checked your engine, transmission and pendulum mounts?

Oem versions are rubber based and that rubber gets worn over the years and mileage and their dampening properties get reduced leading to more vibration thru the cabin. If no codes thrown it's a worthy area to check.

[TriGGER]

I believe I may have a similar issue to yours.

First my car is probably more tired than yours and I would have a guess at being one of the most tired on the forums having just gone past the 186,000 miles mark and I would like to take pride in saying that I have looked after it well. I do 30,000 miles a year, I use the cleanest diesel fuel I am lead to believe, having serviced it twice a year, almost a 4 new tyres a year and I LOVE MY CAR (almost bought a new one last week, but I love my car!!). I just want to add the Sirocco standard lights are absolutely pants - sorry gone off topic.

So my issue has probably been going on for around about 2 years now. I started to hear a rattle under the bonnet and I had no idea what it was, I know the sounds of my car and when I first heard the unusual noise my first thought was to get it to the garage ASAP.

The noise I hear is almost like a rattle, not very loud, but just enough to differentiate it from the normal engine noise. At first I was convinced it was like a tooth had broken off a gear and had dropped to the bottom of its casing. Because of that perhaps it's being dragged around with all those moving parts and then being freed but only to happen over and over. It doesn't affect my idle (not that I've noticed anyway). If I turn the car off and turn it back on it can go away most times. If I continue to drive and the next time I'm stationary it doesn't really happen again. It’s not causing a big problem at the moment, but I can tell it has progressed somewhat from before.

So the sound occurs from a cold start more often than not. It's happened a few times after a VERY long drive but only when stationary (perhaps over 2 hours driving continuously).

I've taken it to different VW garages, and they have all mentioned it could perhaps be a DMF – whether this is just for them to make some tidy money I don’t know for sure. I asked about the price and I think to justify a £1500 cost, I need a severe failure which does not allow me to drive the car.

Recently I went to a separate VW specialist – to talk about performances mods which I didn’t bother with but I did mention the rattle - I can't remember exactly what he said but it was something along the lines that within the DMF something can start to wobble over time and eventually it will need to be replaced.

I mentioned it another time at a VW garage who mentioned – I’m going to get this all the wrong way around but I’m sure someone can correct me here – apparently you can work out if it's the Clutch Plate by pressing the clutch and the problem goes away, or if it's the flywheel by pressing the accelerator and the noise increases (again it's been a long time since I had this information but not sure if I got the information in this post the correct way round.

Having failed to get anyone who can tell me exactly what it is I’ve just decided to leave it be and wait till it fails totally and hope to god it doesn’t effect any other part of the system. I'm sure I've got another 100,000 miles in my car if I can work out WTF it is though.

Just going by what the poster’s in this thread have asked:
I'm not sure what a car misfiring sounds like so I can't work out if it is that.
Idle speed does not jump around at all.
Engine mounts, well I've never asked anyone to check that but it's noted now as it's going in for a minor service in 2 weeks.
The car has been scanned for fault codes a few times since this is an issue on going, I've had an EGR valve fault appear twice – over distant periods - had it replaced now.
Like A4gee, I think when my car is hot it’s hardly happened.
Mine is a 2009 also.