Cold Start v/s Warm Running - Squeaky Noise?

[2k1BeetleTDI]

I have an 2001 TDI Beetle and on Cold Starts it has a squeaky noise under the hood and when it is warmed up, the noise goes away.



Is this okay or is it a sign of problems?



I'm a TDI newb and just got this car. It has 170k miles on it.

Cold start 30F afternoon

https://vimeo.com/157094467

Warmed up after driving 62F

https://vimeo.com/157094566

 

[RacerTodd]

Mine '01 TDI made a similar chirp or squeak sound. Started 30K after my first TB change. Did it when cold, went away mostly as the engine warmed up.

Easy to diagnose.

Remove upper timing belt cover.
Start engine.
Take a wax candle and gently touch it to the edge of the moving timing belt. Make for dang sure not to get your sleeve/hair/jewelry caught in the belt!

If the noise immediately goes away, then what is happening is the timing belt is rubbing up against the tensioner pulley lip. This is the only pulley in the timing belt path with a shoulder or lip. The other pulleys are either flat or toothed, no lip.

This is not an big issue. Mine did this for the next 70K miles. An application of wax would stop the noise for several thousand miles (real beeswax was better than the synthetic wax ones). Applied wax occasionally till the next TB service, noise hasn't appeared since.

If this doesn't stop the noise, then the next step would be to remove the serpentine belt and start the car.
If the noise is gone, it's something in the serpentine belt system.
If it's still there, it's in the timing belt system.

 

[2k1BeetleTDI]

Thanks. I'll try that and see how it goes.