How to fix that squeaking belt
Alfa 916 GTV / Spider Aux belt and tensioner replacement (Twinspark 2.0)
Alfas are notorious for costly belt failures. Fortunately mine has had a relatively recent change of timing & balancer belts which are the most costly and potentially damaging point of failure.
However some strange faults had been developing on mine which resulted in me eventually changing the auxiliary belt and tensioner:
The car had started to stall when slowing down. The revs were just dropping too low. There were no fault codes on the ECU and initially I suspected a vacuum leak or sticking throttle body. However over time a squeaking auxiliary belt seemed to be getting worse. The car was idling fine (particularly after resetting the idle control motor), but revs seem to be dropping particularly at low speeds when steering.
I’m not completely satisfied it was the cause, but changing both the tensioner and belt did seem to solve the noise and the stalling problem. Here’s how to do it:
[disclaimer - this is a free resource to help, I accept no responsibility for damage to your car or person - be careful and sensible and if in any doubt leave it to a professional]
Note: you will need the correct tensioner and belt. These parts vary between the different variations of engine on the Alfa GTV / Spider: best to make check with an Alfa specialist of the correct parts for your car or do careful research first, otherwise you could end up with the wrong size belt or type of tensioner.
Also: take note of the routing of the belt on your car. I will include an image from the Alfa workshop manual below, but taking a photo before you take the old belt off will help.
Loosen the driver’s side front wheel bolts and jack this corner of the car up. Support the car on axle stands.
Remove the wheel to reveal the wheel arch liner. A few tiny screws hold this in place which need to be removed to gain access.
To the left of the large pulley you see the tensioner - it consists of two round sections with hex bolt heads. The black plastic bit (top-left - just hidden by the wheel arch) is the tensioner’s ‘idler pulley’. You need to get a 15mm spanner on this and turn anti-clockwise (just like loosening a normal bolt). A swan-neck spanner is helpful for this. When you turn this the idler pulley will move and slacken the belt, you can then use your other hand to slip the belt off the larger pulley to the right.
Now you should have plenty of slack to remove the belt from all the other pulleys. You will have to remove the belt off the top pulleys by going in from above with the bonnet lifted.
Remove the tensioner by undoing the 13mm bolt that holds it in: the one that goes through the bit that is not the tensioner’s ‘idler pulley’.
Get your new tensioner lined up and ensure it sits correctly on the locating lug(s) on the side of the engine block. Tighten the 13mm bolt down to around 30nm of torque.
Put the new belt on in the correct configuration. Best to put it over the top two pulleys from above first. Then feed it around the other pulleys from below, including the tensioner. Leave the bottom-right or centre pulley for now.
Finally you will need your 15mm (preferably swan necked) spanner to turn the new tensioner’s idler pulley the same way (anti-clockwise) again. This will allow you enough slack to slip the last remaining part of the belt over the last pulley. It is fiddly work, and might take you a few attempts as it requires some strength to keep the belt tension loose enough.
Double check the routing of the belt, check the area around the belt is free from any tools or human extremities, and then fire that bad boy up.
Two things will help - a lengthy enough swan-necked spanner for loosening the tension (and/or some muscle) and jacking the car high enough that you’re not groveling around too low down.
This is a fairly quick and satisfying bit of preventative maintenance and may even solve a few issues like those I experienced.
Stay safe, have fun and may the Gods of Alfa Romeo forever shine upon you