2.0 TDI Auto - Vibration When at Idle In gear D, R, S or P

[Luke...]

Hi,
New to this forum, and have signed up in the hope someone may be able to offer some advice on the cause of my issue. I have a 2007 A4 B7 2.0 TDI BRE engine, Auto tiptronic transmission.

The car has done just over 180k and after a year of ownership, I have decided to start sorting some of the small issues that are bugging me. My driveshafts where originals and the inner CV joints where shot, i used to get heavy vibration when accelerating so I have recently replaced these with 2 new aftermarket shafts from a reputable company. Ever since I have changed these I now get a vibration when in gear, I don't think it is related to the new shafts but in fact that I have always had the vibration and the old shafts had SO much play in them that they were taking up the vibration and now that the shafts are solid, I can now feel it.

When I start the car from cold it is worse. I get a vibration through the interior and can feel it in my seat, its so bad that it vibrates the passenger door card. I don't feel it at all in the steering wheel. The vibration I feel is only when the car is in D, S or R, if it is in N then i don't get it. If I put the car in park when on a slight hill or slope and take the handbrake off so it locks in park then I get the vibration again. It can only be felt when im at idle, when driving I don't feel it but when im sat at a set of lights I feel it again when im stopped, the car idles around 1000rpm and the vibration goes away around 1200rpm. 1000-12000 the car feels like it running lumpy.

I feel it again when under heavy load such as quick acceleration or if the gearbox kicks down into a lower gear when going up a hill.

So far I have changed:
The drivehafts as mentioned above
2 new front tyres and wheels balanced
New powerflex snub mount
New lower gearbox mount

The vibration is no better, but is big enough that I want it sorted as you can imagine.

Hopefully someone can shed some light on the matter, Im happy to do a lot of jobs on my cars and have rarely needed the help of a garage but im debating putting some garage labour aside and see if they can spend a few hours diagnosing the fault.

Cheers

 

[Mario]

I've just spent the last half hour looking for this diagram! finally found it! From what you describe it is most certainly related to a mount or bushing. It seems like when the gearbox is engaged with the engine, the engine vibration is then being transmitted into the cabin of the car.

Snub mount? Not a chance, no point in touching it. It attaches the engine to the front of the car. You need to focus purely on what secures the gearbox, because when you are in N and the box is dis-engaged it's fine, and only happens when the box is engaged to the engine.

Have a look at this diagram.....

I am guessing you replaced item 10 when you said you fitted a "New Lower Gearbox Mount".

If that has not cured it then I would start looking at the sub-frame mounts. Namely the rear mounts item 26.

The reason I say the rear ones is because the engine console plates (where the engine mounts fit into) share a mounting point with the front sub-frame bushes. So if they were gone I would expect the vibration to be there all the time, but as it's only there when the box is engaged I would be looking at the rear, as the gearbox carrier item 1 shares mounting points with those.

Hope that helps. Get under the car and see if you can spot anything with the rear sub-frame bushes.

NOTE: If you end up removing the rear sub-frame bolts (item 3), you WILL need to replace them as they are torqued to yield and stretch when installed.

 

[Jasesapphy]

Luke
New powerflex snub mount could b causing the issue, they are very stiff and the derv's vibrate more than the petrol, it could be that its vibrating though the chassis

 

[DieselJake]

I'm not very familiar with Auto's but it could be something within the actual assembly like the ball or something which is shaking.

Worth making sure everything's tight as a drum in the engine bay too as I've had a few things loose shaking the car which have since been tightened.

Could be flywheel or something shaking it too.

 

[Jasesapphy]

I'm not very familiar with Auto's but it could be something within the actual assembly like the ball or something which is shaking.

Worth making sure everything's tight as a drum in the engine bay too as I've had a few things loose shaking the car which have since been tightened.

Could be flywheel or something shaking it too.

Jake no flywheel on a Diesel, first cheap test is change snub mount

 

[DieselJake]

Jake no flywheel on a Diesel, first cheap test is change snub mount

... Would you like to see the flywheel which came out of mine... 2.0TDI's have a dual mass flywheel just like my 1.9TDI

You are wrong about the snub mount (as someone else has already pointed out!), a stiffer snub mount may increase vibration on idle but the entire purpose is to stop lift/vibration when the car is accelerating. Feel free to post another (third!) comment suggesting how exactly this supposed "cheap test" aka downgrade will improve the car, baring in mind myself and a few others have either the same or similar snub mounts.

I've only just noticed the engine mounts weren't replaced, these are prone to leak and you should be able to (just about) see if they have leaked by looking down the engine bay seeing if there's black fluid under the one side (from memory only one side contains the vibration dampening liquid), if not a scan should pick this up as it's connected to a sensor. Replaced mine with solid B5 RS4 one's which increases vibration a little on idle but feels like a race car shake or something haha kind of hard to explain, plus they'll never need replacing again as they're solid.

 

[Jasesapphy]

Jake it's an auto hence no flywheel
Manuals have a DMf

 

[Mario]

Jake it's an auto hence no flywheel
Manuals have a DMf

To be fair to Jake your first post never said anything about an auto. You said diesels don't have a flywheel.

Jake no flywheel on a Diesel, first cheap test is change snub mount

Also, as I and Jake have said, changing the snub mount is a waste of time, and the OP has said they have already done that. Logically it HAS to be gearbox mount related. Think about it. When the engine is on and the gearbox is in N it is dis-engaged from the engine and there is NO vibration. As soon as the OP puts it into ANY gear and the gearbox engages with the engine he feels a vibration.

That has to mean that when the box is engaged the engine vibration is travelling through the box and "grounding out" on somewhere, transferring the vibration to the chassis.

If the fault was engine mount related it would happen all the time, even in N, but the fact that gearbox engagement is the KEY factor that causes the vibration means it has to be related to how it mounts to the chassis.

The OP has already replaced the rear lower gearbox mount. As per the picture I put above, from that mount it attaches to the sub-frame, which then attaches to the chassis. So if the gearbox mount is good (new), the next step would be the sub-frame bushings, as they are the next link in the chain between the gearbox and the chassis.

 

[Jasesapphy]

Yes should have said autos, I was replying to the post above that said auto

Trust me I know manuals have DMFs my BMW 330d has had 2 of them at £350 each

 

[Jasesapphy]

look box related then, I had an issue with poly mount on 330d causing vibration.
It was sending vibration through cab.

But as you say, if it's not happening in N then it's when the box is loaded up

 

[DieselJake]

Could get something like this if you think it may be subframe bushes (they're solid though so may again increase vibration).

https://www.awesomegti.com/shop-by-...nt-subframe-alloy-bushings-audi-a4-s4-rs4-b7/

Tempted to get myself a set actually along with an 034 gearbox mount.

They also have rear subframe mounts which I might get.

https://www.awesomegti.com/shop-by-...rt-billet-aluminum-rear-subframe-bushing-kit/

 

[Jasesapphy]

Our race car has a solid mounted engine and box, my word shakes quite bad
Misses seems to enjoy passenger rides however

 

[carlcall]

Hi Luke....you say you've put both a new powerflex snub mount and a new lower gearbox mount on.

Did you do them both together or the powerflex one before the lower/rear mount?

I know that my diesel doesn't give any vibrations at all with the powerflex snub mount, even with the clutch biting at a junction.....in fact you would think it was just the OEM one if you didn't know.

 

[Luke...]

Cheers for your help and replies lads. Yup lower gearbox mount is brand new, the old one had nothing visually wrong with it when i took it off but i though might as well fit new as i was already that far into the job and already had the new part. SNUB mount was fitted about a week before the gearbox mount, I didn't notice a difference after fitting but the old one was only slightly cracked, it wasn't completely dead. I have realized that I didn't center the snub mount before tightening the mounts, but I have had another look at it and the gap seems pretty even the whole way round.

I am going to check engine mounts today. I have had a quick look before and the passenger side one looks fine, I cant see the drivers very well as there's an air box and a turbo in the way lol, but I do have a small engine oil leak which I cant find at all where its coming from so hoping it hasn't covered the drivers mount as wont be able to tell if its leaking. Would you be able to see a heavy vibration when engine is idling if you were to look at the engine mounts or even if they were shot would they still look ok?

I have had a strange possible cause of my vibration. I plugged my car into the scanner the other day for an unrelated issue, whilst I was there I ran diag on the engine and it threw up 2 fault codes. 1 was turbo underboost and the other was MAF low signal. Bit of research showed both could be down to a dirty or broken MAF so I unplugged it and started the car, vibration was loads better, took the maf out and cleaned it, it didnt seem dirty but now the vibration is much better

I am still however getting a vibration through the car when accelerating up a hill, when for example the car kicks down. I thought they were related but with the idling vibration better, im not sure they are anymore

 

[Luke...]

Ok Nope im telling lies. Went out in the car this morning, vibration is back and same as it was before. Unplugged MAF and vibration is the same so I think it was just a coincidence the vibration wasn't as bad when i was sorting my MAF.

A strange issue as went out in the car loads yesterday and didn't once get the vibration.

 

[Nazim Uddin]

Luke I don’t suppose you managed to find a solution for the vibration?? My 07 A4 B7 2.0 tdi estate vibrates when idling in D S and R. I’ve had the wheels refurbished balanced engine/gearbox mounts replaced fuel injectors refurbished and duel mass flywheel replaced to no joy. When I’m coasting in rolling traffic I get a weird vibration that comes then goes every few seconds.

 

[DieselJake]

That sounds like the fluid from one of the engine mounts has gone, way to check is park (with the handbrake up) put it in gear and see if it shakes loads... or is it supposed to shake loads on idle then stop in gear... think it's the first haha I'm getting old, bring 'em to Birmingham and I'll diagnose any problems with engine mounts easy, can't fix 'em mind but I've had enough VAG mounts replaced that I know what each one feels like when it's shot. Can also see the fluid in the engine bay (if you look REALLY hard) if the mount is shot.

 

[Nazim Uddin]

I've had em replaced with OEM ones.

 

[Nazim Uddin]

Wheels have been refurbished as well.