A4 B8 2.0 TDi Problems Starting, Rough Idle & Steering Knock

[jamin128]

Please help ... I think I may have bought a lemon :-(

I have a 2008 A4 B8 2.0 TDI which has done 80,000 miles ... I am having starting problem, rough idle particularly when warm & a steering knock.
I have had the car about 4 months, and it has always been rough on idle, but it seems to be getting worse.

The car struggled to start sometimes, and as it still had its original battery which wouldn't hold its charge, i decided to replace it. This didn't make any difference to the starting :-(

Not long after this (about 4 weeks) the coil light started to flash very briefly every minute or so, and then the engine light came on.
Did a scan with VCDS and it came up with the throttle valve and a glowplug. I replaced the throttle valve and all 4 glowplugs.
Cleared fault codes and they haven't returned, although the car is still running rough :-(
*** Not sure if this is relevant, but the pipe that connects to the throttle valve had and still gets oil in it ... is this normal ?

I have tried injector cleaner, and premium diesel, although I always fill up at BP regardless.
I also had a full service carried out, although it was only at a local garage.

Now the steering makes a knock at low speed when turning from right to left / left to right. I have noticed that the steering pump has become very noisy, it sounds like the bearings.

My knowledge on cars is very limited, but I am keen to learn :-) ... Also, funds are limited!!!!
Can anyone help me with, and or point me in the right direction to diagnose any of the above problems. I have VCDS and a tool kit.

Thank you in advance, any help is much appreciated :-)

*** Sorry I forgot to mention that I had 2 new front tyres fitted prior to the knocking noise, and when I collected the car the steering was off center, although this seemed to rectify itself!!! The steering has only recently started making a noise.

[Guest 2]

When did it last have a MOT?

[jamin128]

It had an MOT about 5 months ago before I bought it.
I did forget to mention that I have also had 2 new front tyres fitted, and when I picked the car up, the steering seemed to be off centre, although this seemed to rectify itself!!!

[Embisix]

Can't comment on the other issues but the steering knock could be the lower part of the steering column (the section that has a UJ just before it disappears through the bulkhead, inside the cabin). Had a similar issue recently and a new section cured it. Cost about £300 fitted at local Audi dealership.



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[jamin128]

Thanks for your reply, I was hoping it would be a cheap fix!!!
Will try and get under the car to have a look :-)

[Embisix]

It's not under the car, and Audi couldn't even diagnose by way of excess movement in any component. They only sorted it by replacing various sections of the column. Turned out to be the lower half of the internal section in my case....

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[jamin128]

Doh :-(

[Embisix]

That was the diagnosis I had, your issue may be different of course.

If you do decide to get underneath, you'll need to remove only the engine's rear splash-guard (5 minute job) and greasing the universal joint closest to the rack. You'll see it and your steering rack very clearly by lying on your back and looking to the right of the engine/sump. There's a UJ squeezed in between the engine and the exhaust. On mine (a TDI), it's about 10-15mm from the exhaust and seperated by a very thin heat shield (I've had takeways in thicker containers!).

It's a terrible design in my opinion and you'll probably find the UJ is dry, so worth packing it with some good quality heat resistant grease. This may solve the problem, it may not but the grease certainly won't do any harm and it's always interesting to have a poke around underneath anyway.