Audi A4 Belt Squeak

beanie10

Hi all, hope someone can help me here.
2004 audi a4 1.9 tdi- when I drive through a pool of water the heads lights dip, wipers slow down. After about 15-20 seconds I can hear a belt squeak and everything is back to normal.
I also noticed today that main belt drive pulley (camshaft pulley I think) which drives the belt around the alternator and power steering pump has a wobbly in it while ticking over- all the other pulleys are spinning perfect.
Is this something to be worried about?

martyc5674

If your interpretation of wobble is that the tensioner is jumping up and down excessively it's prob down to a worn pulley.
Could be idler pulley tensioner or crank pulley... Or all three. (or a big end bearing but hopefully not for now!)

The crank pulleys on high torque diesels are also a harmonic balancer( they have weights offset in them to counteract engine vibration... The pulley is also typically made two parts bonded to a common piece of rubber to limit the pulses reaching the aux drive...and these wear/fatigue with time causing whip on the aux drive which displays itself often as a bobbing tensioner.

Your belt is obviously slipping so that's first on your list to replace but check the pulleys condition and try get rid of the bobbing.


Just re read your thread... Sounds like crank pulley is shot...was it off recently by any chance???
Marty.

beanie10

Thanks for the reply.
Only have the car 3 months so I dont know what work was done.
Looking straight down on it the crank pulley spins as if its buckled which in turn causes huge vibration in the tensioner.
As you said first thing Ill do is change belt and probably pulley.

martyc5674

Ok that sounds dodgy if its wobbling side to side...that comes off and there could be a lot of damage done.
If i were you id take the pulley off and inspect it....it may just be loose.

I put one of these on before and accidently ignored the locator dowel on it(these pulleys have an orientation/locator that lines up with the crank) and it wobbled like your describing until i rectified it.

Marty.

carefull now!

Alternator pulleys give trouble on them too, check the one way clutch on the pulley itself, remove the belt and see will the pulley free wheel one way and lock the other way.

Xpro

carefull now! wrote: »

Alternator pulleys give trouble on them too, check the one way clutch on the pulley itself, remove the belt and see will the pulley free wheel one way and lock the other way.

This is more likely. Was just about to say that.

Alternator pullies give a lot of trouble

martyc5674

Xpro wrote: »

This is more likely. Was just about to say that.

Alternator pullies give a lot of trouble

I would say less likely in this case!!
Those clutch pulleys do give trouble but it's not going to cause the crank pulley to wobble.....
Marty