Tapping/Knocking Noise

[Funkyfin2000]

Hi All,

Have an A4 Avant 130pd tdi 2004 Reg.

I've always had a problem with lumpy starting and the car chucking out quite a bit of smoke on start up. Normally worse on Colder says.

Yesterday upon starting the car, I could hear a tapping/knocking noise. Appears to be coming from the front.

I could hear it without the bonnet open. It's irregular. Seems to go away once warm, say 2-3 mins after starting but then occasionally happens. Don't think it got worse or faster upon revving the car as far as I could tell.

The engine rocks/shakes quite a lot and always has done.

Anyone got any ideas? Alternator Pulley and CamBelt all done a while back. It taps heavily when pulling away heavily, but this might be just due to the oil getting round the system I guess.

Anyone got any ideas?

Rich

 

[alpesh26]

Hi All,

Have an A4 Avant 130pd tdi 2004 Reg.

I've always had a problem with lumpy starting and the car chucking out quite a bit of smoke on start up. Normally worse on Colder says.

Have you tried changing the glow plugs? Mine used to do this, changed the plugs and it starts much smoother - cost about £30 for 4 new glow plugs. They're pretty easy to change, just watch you don't snap them when taking them out or you'll be screwed

 

[Funkyfin2000]

Yeah they were all replaced with genuine ones too.

I have a fear its camshaft issues.

The car has a misfire/flat spot about 2-3k sometimes and smokes a lot at start up!

Lumpy running etc....oh dear

 

[mememe]

I had a similar noise. Look here (read it all). Then found the problem was an engine mount look here.

I didn't check properly UNDER the engine mount to see the securing nut. Only found it while I was replacing the starter motor.

 

[Funkyfin2000]

Hmmm not sure it's that given the other symptons.......but will get it checked, thanks for the heads up.

The smoking and the juddering engine worries me the most.

Going to be going to BVRautomotive.co.uk in Stoke shortly to see my good friend Dave!

 

[Funkyfin2000]

Im stil geting this.....just rnuning at idle when warm or cold you get irregular tapping at the front of the car.......its very odd!!!

Any ideas!

 

[Funkyfin2000]

Got to the bottom of it... Air Con Compressor Clutch £430 fitted! Doh!

 

[Funkyfin2000]

Twas all fixed with a clutch kit........£150 or so job done! Really pleased!

 

[Enzo_UK]

Twas all fixed with a clutch kit

Not many B6 that I have worked on even have a clutch on the aircon pump anymore!

The pumps are always driven, mainly to stop them siezing up when people dont use it over the winter like cars of old, but with modern climate control they needed more than just off and on with the pump....

The pump has an internal bypass valve that is PWM driven from the climate unit, and bypass valve just lets it pump the fluid round inside itself, or valve shuts and then pump pushes fluid round the rest of the aircon pipework, so it can modulate to provide a suitable amount of cooling.

The pulley does have a rubber damper type thing inside it to cut down vibration, and these can break up, but you can get the rubber bit for £25, but have to drill out the rivets in the pulley to change it, and then rivet pulley back together.

 

[Funkyfin2000]

Apologies, it wasn't a clutch kit it was a pulley kit that included the rubber bits! You can't get the rubber bits desperately anymore!