Deep vibrating noise when idling, squealing noise when turning wheel full lock - HELP! 1.9 TDI

[vonny232]

Hi Guys,

I dont often post here, but I have a problem with my 2004 1.9 TDI (185,000 miles) which I really want to get to the bottom of.

About 2 weeks ago I noticed some unusual noises coming from the Engine area of my car.
1) When the car idles, I get this deep grumbling vibrating noise coming from the engine area.
2) When I turn the steering wheel full lock either way (usually when slowly pulling away from a parked position), I get a shrieking/squealing noise which becomes more pronounced if I put additional pressure on the wheel when fully locked.

I took the car to my Garage (A VW dealership with official Audi repair centre) and they told me it was probably a worn flywheel and would cost over €700 to repair (or over €1300 if they did the clutch at the same time) which is extortionate. This was based on the opinion of a mechanic listening to the noise. There were no Engine warning lights and no error codes were available on the car computer.

The Mechanic said the squeaking sound was related to the alternator pulley system slipping, and he put some grease on it and told me to monitor it (It didnt help and is still making the noise).

I was talking to some friends and they said this might be a wrong diagnosis.

The reason they were sceptical was because the other symptoms didnt sound like a flywheel problem:
1) I dont feel any vibration through the wheel or gear stick at all. In fact, apart from the vibrating sound, I dont feel any vibrations at all.
2) The vibration sound only occurs when the car idles. If I touch the accelerator (either out of gear, or when driving) the vibrating noise stops entirely.
3) The car has the same performance it always had. I feel no decrease in performance at all.
4) Its a funny co-incidence that I got the squealing noise when turning the wheel full lock at exactly the same time I got this vibrating sound. I cannot see how I suddenly get a worn flywheel on the same day I get a squealing alternator pulley system.

I might be totally wrong about this, but I want to try and get a better idea of the problem before I consider spending a lot of money on a car which is getting rather old now anyway (The Garage would probably charge me regardless of whether this is the actual cause or not).

I read somewhere it might be a damaged Alternator pully which can make a similar deep vibrating noise, which would tie into what I described about the squeaking but in reality I have no idea.

Can someone please help me identify this, or allow me to at least eliminate/narrow down some of the possibilities?

regards

Danny

[zollaf]

the alternator pulley is a freewheeling clutch type. engine off, use a pointy thing such a sa screwdriver to turn the fan inside the alternator. you should be able to turn it in the norml direction of rotation as if the engine is running, but not the other. start the engine and watch the tensioner, see if it jumps about. if the tensioner jumps and the pulley is seized, replace the pulley. about 65 quid and an hour but you do need a special tool and a windy gun, so best left to a garage, or remove the alternator yourself and take that to a gaarge along with the new pulley, as long as they have the tool, but not the garage you went to, i think they are best avoided if they cant identify a faulty pulley. grease will do nothing if its seized.

[vonny232]

Hi, thanks for the reply.

How can I turn the alternator if the engine is off? Isnt the alternator tied to the engine so it wont move unless the engine turns over?

How can the pulley be siezed if I have been driving to work for the last 2 weeks? Wouldnt it stop the alternator turning entirely?

[zollaf]

the pulley is a freewheel, a one way bearing, the engine turns the pulley and thus the alternator when its running but allows the alternator to also run faster than the engine. so with the engine off you need to be able to turn the alternator one way but not the other. you do this by turning the fan blade inside it that would spin if the engine is running. you need to be able to turn it one way but not the other. they fail and lock up and then the aternator cannot freewheel and you get a lot of noise and vibration.

[vonny232]

Ok, I can try that. Though as I say, once I touch the throttle the vibrating noise stops entirely. Does that make sense regarding the pulley?

[zollaf]

yes it does. it wont stop entirely, it will just be far less. if the fault is your pulley and you fit a new one then you may well be surprised just how important they are..

[vonny232]

Hi,

I just went out to the car and took a small screwdriver and poked it through one of the air grill holes and put pressure on the fan blade one direction and the other. It was stuck solid both ways.

If I put some firm pressure on the screwdriver, I could see the tensioner and belt flexing slightly both directions, as if the strain was being transferred into the belt (i.e. it was not spinning freely).

I guess that proves that the pulley is damaged?

Is this a standard part? I know a machanic who doesent mind me supplying the parts. Do I need a specific engine number part, or will any pulley work provided its for a 2004 A4 B6 1.9 TDI?

[zollaf]

i think theres only one choice for your car. you want one made by INA, although if you get a gates one it will most likely be an ina anyway for a tenner less than one in an ina box.

[vonny232]

I ordered an INA 535001210 which I measured and seems to be the correct one. Went to a different mechanic to the main Audi garage and they agreed its probably the Pulley. Got a quote for 30-40 quid labour if I supply the part.

Thanks for the help.