Just fixed a leaking hose, and noticed the water pump belt is pretty slack.

I assume the belt has just stretched over time so have ordered a replacement- or could there be another reason its slack?

I couldn't see a tensioner, so assume it just goes around the water pump pulley to the small pulley on the balancer shaft?

2.0 tsi

No tensioner. They're a pain to change as the pulley on the balance shaft has to come off. Pretty much impossible without a good deal of disassembly. Its a toothed belt and is not highly loades. Often, they are not replaced even with the water pump due to the pita nature of it.

Yeah it did look quite inaccessible.

It doesn't look in bad condition, just fairly slack, and concerned it may snap/snag, and overheat!

17 hours ago, major-eyeswater said:

I assume the belt has just stretched over time so have ordered a replacement- or could there be another reason its slack?

Yes, they generally slack when they have coolant dripped all over them; usually from a leaking water pump.

No coolant, it's bone dry, just didn't know if it was too slack.

58 minutes ago, major-eyeswater said:

No coolant, it's bone dry, just didn't know if it was too slack.

I think you may have misunderstood me. If coolant drips on to the belt, it would cause it to stretch/slacken. It might be dry now, but generally you would need a new belt. Tail-tail signs are staining on the top side of the belt.

Plenty of info on Youtube.

7 hours ago, major-eyeswater said:

Yeah it did look quite inaccessible.

It doesn't look in bad condition, just fairly slack, and concerned it may snap/snag, and overheat!

Not the best photo. The TCMU connector block is right in the way. But if you search some you tube videos for the change you'll see what it is like at the balance shaft end! It is captive until you release the pulley. And you need a right angle pneumatic wrench of similar I think.

On 11/03/2025 at 15:54, major-eyeswater said:

Just fixed a leaking hose, and noticed the water pump belt is pretty slack.

I assume the belt has just stretched over time so have ordered a replacement- or could there be another reason its slack?

I couldn't see a tensioner, so assume it just goes around the water pump pulley to the small pulley on the balancer shaft?

2.0 tsi

Thinking back to when I did the thermostat and pump. There is enough slack in the system to push the belt off the teeth in of the pump pulley and refit without removing anything, That's what I did. So it is not strongly tensioned. But not super slack either..