Vibration through steering wheel

[Coinneach]

Hi All

Octavia 2008 1.9tdi Elegance, 45,000 miles

When I bought the car, there was a small vibration through the steering wheel from 60mph upwards.  I had all the 4 pretty new tyres (Pirelli P3) that were on the car balanced, turned out they had never ever been balanced after fitting.  This cured the vibration.  However, I discovered that if I knock the car out of gear going down hill at 60mph, or above, the vibration instantly returns.  Put it back in gear and it goes away.   This vibration feels just the same as needing to have the tyres balanced.  Any ideas as to why or what may cause this?

 

I also discovered, after having the tyres balanced and thus able to drive a bit faster, that braking from about 70mph also caused quite a vibration on the steering wheel which disappears when the speed comes down to 60 and below.  There is no vibration while breaking at lower speeds, so it seems unlikely to be buckled disks.  The disks seem to be fairly new, with little wear.  Again, any ideas?  This problem to me is a bit more worrying.

 

The two things may be related, or not, I really do not know.  Thanks in advance for any and all help.

[Tilt]

Higher speeds will make any vibrations more noticeable, especially whilst braking, IMO.

 

Either warped discs or loose caliper / carrier or even wheel (tho doubt the last one is likely). Or wheel bearing, possibly.

 

Check brakes, check for any loose brake components and wheels.and check wheel weights are still on (I suspect you will have already done this last bit).

 

But IMO has to be discs as most likely............I have had the same issue and it was warped disc.

 

As for the out of gear vibration.........Don't push it out of gear.........would be illegal in this country i believe

[Jevpls]

Yeah, warped discs could be the cause. I've had similar problem and the first thing I did was re-balancing the tyres. Didn't help at all. When it became more annoying (especially while braking) I suspected the discs and it was the cause.

Actually the only way (at least I think so) to check this is to change the discs.

[Tech1e]

9/10 it’s not actually a warped disc but contamination. Especially common on autos where you might pull to a stop and hold the car stationary on the brake. 

[J.R.]

15 hours ago, Tilt said:

As for the out of gear vibration.........Don't push it out of gear.........would be illegal in this country i believe

 

Like walking on the cracks in the pavement?

 

I wonder if people with the latest generation of DSG equipped cars know they could be locked up and the keys thrown away!

[Coinneach]

Thanks for all your replies and advice.

 

As regards the knocking it out of gear going downhill, I wondered if it might have anything to do with the driveshaft(s), ie the constant velocity joints.  When out of gear, the wheels are driving the transmission train back to the clutch, instead of the usual way round.  So everything is loaded backwards.  Light load, true, but backwards.   Surely if it was the disks, the vibration ought to be there all the time, in or out of gear.  Which it is not.  Until I start to brake, at 70mph.  What I cannot understand is why there is zero vibration when braking at, say, 50mph.

 

Tech1e, can you tell me what you mean by contamination?   I always hold the car on the footbrake, seldom use the handbrake.  Disks have probably been replaced, too good for 45,000 miles, only a very slight lip on the edge.  Might be cheap chinese replacements, though. Changed before I bought it.  Bit annoying if it is the disks, I had hoped to get another 20,000 out of them.  As you say, Jevpls, the only way to find out is to change them.  Should I just change the front to see if that cured it?

[Tilt]

I'm a little like this  about the contamination comment......but i may have the wrong end of the stick???

 

I can't see how contamination can cause steering wheel wobble..........(tho Tech1e gives out some good advice ).

 

@Coinneach me having now mentioned steering wheel wobble and you only mentioning "vibration" (i think)..............Do you get steering wheel wobble, or is it just a vibration.

I assumed you were talking steering wobble, side to side slightly.

[Tech1e]

On 02/07/2019 at 14:00, Coinneach said:

braking from about 70mph also caused quite a vibration on the steering wheel which disappears when the speed comes down to 60 and below. 

 

1 hour ago, Tilt said:

I can't see how contamination can cause steering wheel wobble..........(tho Tech1e gives out some good advice ).

 

Brake judder...

 

What can happen if you clamp brake pads on a hot disc then you get a material/dust transfer that bakes onto the disc. This causes a tiny raised part of the disc which causes judder. 

Edited 3 July, 2019 by Tech1e

[Tilt]

Yes, I was thinking as mine was, wheel wobble and warped disc....

[Morph]

I’ve just had very similar problems and mine was a leaking rear shock. 

[King85]

On 03/07/2019 at 12:59, Coinneach said:

Thanks for all your replies and advice.

 

As regards the knocking it out of gear going downhill...

 

You're car is at its most efficient on over run rather than idle so when you knock it out of gear to coast you're doing the opposite of what you think you're doing.

[Coinneach]

Not many people will remember the old "Mobil Economy Run" where drivers were challenged to get the maximum mpg using whatever tricks they wanted including obviously free-wheeling whenever possible.  It was a long time ago before cars had ecu's, or any electrics except a spark plug!  They achieved remarkable results.  In those days it was true that free-wheeling did save on fuel as the minimum amount of fuel that could be delivered was that set for tickover.  So the less revolutions the engine was doing while free-wheeling, the less fuel used.

 

King85 is quite correct, nowadays (with diesels anyway) when you take your foot off the throttle in gear, NO fuel is delivered to the engine.  So that becomes the most economical way to coast - in gear with the foot off.  As soon as you knock it out of gear, enough fuel has to be delivered to the engine to allow it to tickover.  Thus marginally less efficient.

 

Back to vibration - no, not a wobble, just vibration, I am coming to the conclusion that it is the disks and, as it is liveable with and I do not think it is causing any other problem or accelerated wear, I will wait and see if it is going to get worse or not - and of course keep the car in gear at all times!

[J.R.]

The above is incontrevertably (dont think thats a wod!) correct if you have to stop at the bottom of the hill or are slowed by traffic ahead of you, if there is a long straight or an uphill section above then the fuel saved by engine braking in gear will be offset by the increase in speed carrying you much further when coasting before you need to get back in gear and on the gas.

 

It all depends on how long the descent, how much speed you can gain and what lies ahead, I did enough repeat journeys when money was really tight obsessively watching the fuel consumption to work out when it gained and when it didn't, when it gained it could be very significant.

 

Future generations will probably have a decompressor to limit the engine braking on over-run.

[Tilt]

1 hour ago, J.R. said:

The above is incontrevertably (dont think thats a wod!)

 

No, I don't think wod is either, Lol.