Mk7 Belt/Pulley Squeal issue, only over 2000revs

[jroddy]

Gday,

Have had a belt squealing issue for a couple months now and each time I make some sort of change it persists. Currently the squeak only happens above 2000rpm and gets louder as revs increase beyond that. Its a 2007 2.4L rwd.

Initially I started with the obvious fixes: new belt, new tensioner, new idler. No luck. It seemed more investigation was needed. Next thing was the fan hub clutch as it had far too much play (in hindsight this was unlikely to be my squealing problem but was glad to replace it regardless). Then the cooling fan pulley was next, I noticed the belt was running towards the front edge of the pulley instead of the back. Still no luck. At this point i talked to an uncle who works at ford, he said that the belt brand may have something to do with it. I decided to spend the extra cash and put on a genuine ford belt instead of the dayco one I had chucked on earlier. This immediately fixed the problem but the squeak came back (a different sound this time) after not even a week.

At this point now I'm assuming its a bearing in one of the pumps, the crankshaft/harmonic balancer being worn or something else entirely, but am not sure what the best process is for diagnosing its source. I'm hoping one of you blokes here have had or heard of a similar experience. Cheers for ya help in advance, this squeal has been doing my head in.

- One very lost bloke from down under

[tbullivant]

not sure on the mk7, but the vacuum pump was leaking oil onto my belt on my mk6 causing it slip and screech. new vacuum pump to stop the leak then a new belt fixed mine. Is there anything leaking that might be contaminating the belt?

[jroddy]

Cheers for the reply mate.
Can't see any obvious coolant or oil leaking onto the belt. I know a bit of water gets in from the engine bay seal but wouldn't expect that to be the cause. Was your leak an obvious one to spot? Maybe ive gotta look a little closer

[tbullivant]

No not obvious, it was a very slow leak. Under the vacuum pump pulley was all contaminated and you could see a slight oil weep where the vacuum and water pumps bolted together. Tried a new gasket first but it wasn't that, it was the pulley on the vacuum pump so out a new one on.

[jroddy]

Update on this. In the end was an alignment issue, fan pulley was replaced but not aligned with the surrounding pulleys. Couple washers to bump it out one side did the job. All is well