Engine Noise After Timing Belt Replacement

Hi!

Recently, the timing belt was replaced in my Golf TDI PD (ATD) at a VW workshop (90,000 km, and it cost 1000 EUR along with a few other minor things). When I picked up the car from the workshop, I immediately noticed a strange rumbling sound, which only occurs at idle speed.

So, I had to take it back to the workshop right away. The mechanic confirmed that the noise was 'not normal,' but he didn't want to do anything about it immediately. He said the noise usually comes from the timing belt being a bit tight, but the ATD has an automatic tensioner, so I shouldn't worry. It definitely wouldn't break, and he told me to just drive another 1000 km. If the noise was still there after that, he would 'take another look.' Also, the timing belt would naturally stretch over time.

Can you believe this, or is it just pure BS? Because nobody wants to take the whole engine apart again just to properly install the timing belt! By the way, the knocking sound is barely audible when the engine is cold, but it gets louder when the engine is at operating temperature.

tom76de wrote:

. The noise usually comes from the timing belt being a little tight, but the ATD has an automatic tensioner, so I shouldn't worry. It definitely wouldn't break, I just need to drive about 1000km, and if the noise is still there then, he would "take another look"... Also, the timing belt would naturally stretch over time. Can you believe this, or is it just pure **bull** because you don't want to have to disassemble half the engine again just to properly install the timing belt? By the way, the knocking sound is hardly audible when the engine is cold, but it gets louder when the engine is at operating temperature

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Hi,

I think that's nonsense, because the automatic tensioner is specifically designed to ensure the correct belt tension.

However, the tensioning roller must be pre-tensioned according to the regulations to ensure that its adjustment range covers all operating and temperature conditions, and that the pre-tensioning force is correct.

The fact that the noise is loudest when the engine is warm suggests that the tensioner pulley has been tightened to its maximum limit and cannot give way any further as the belt tension increases with rising engine temperature.

In my opinion, substandard work was performed here, which not only overloaded the belt but also the bearings of the tensioner, water pump, etc.