Humming whistle from rear of car

[Rholtby]

Evening all, I'm hoping someone here can help. The other night whilst travelling back around the M25 I could hear a humming & whistle coming from the rear, a similar sort of noise to carrying ladder on a roof rack. The car also feels as though it's not pulling away as strong.

Could this be rear pads not releasing properly or is it more likely to be barings? I say pads as occasionaly I get a check brake pad warning I thought faulty sensor, new pads and discs less than 6 months ago which took the garage 2 days as they couldn't remove the part that the caliper attaches too.

I have since gone on a short drive a d found the brake discs to be extremely hot, is this likely to be a seized caliper as I've I'd this suggested to me?

Any advice would be great.

Thanks

[Dogma]

Sounds like the calipers to me

[Rholtby]

Thanks. I've got 2 new calipers so going to give it a go

[Dogma]

Thanks. I've got 2 new calipers so going to give it a go

gl

[Rholtby]

So I've changed the calipers and bled the system. The brakes don't seem as harsh as before, must need bleeding again, but they do work. Now the handbrake is non existent so that needs adjusting. BUT most annoyingly the humming/whirring is still there  I think once the problem is solved its going to be time to move on from it

[pudding]

Wheel bearing probably.  Jack the rear up with handbrake off and spin the wheels. You will hear the dodgy one.  Not worth shifting the car on for such a minor thing that ALL cars suffer from!

[MIJ_JAGGER]

+1 for wheel bearing
Had the humming on mine little while back, changed both rear and all good now

[Rholtby]

Wheel bearing probably.  Jack the rear up with handbrake off and spin the wheels. You will hear the dodgy one.  Not worth shifting the car on for such a minor thing that ALL cars suffer from!

Thanks. That was my original thought. Seems I've wasted time and money on the brakes now. The car just seems to be costing all the time. Are the bearings easy enough to change?

[pudding]

Wheel bearing probably.  Jack the rear up with handbrake off and spin the wheels. You will hear the dodgy one.  Not worth shifting the car on for such a minor thing that ALL cars suffer from!

Thanks. That was my original thought. Seems I've wasted time and money on the brakes now. The car just seems to be costing all the time. Are the bearings easy enough to change?

Nature of the beast I'm afraid mate, and all other performance German cars.  You will get the occasional big spend on them but the rewards are worth it imo.

The rear brakes seize up anyway, so that wasn't wasted money.  Treat it as preventative maintenance 

Yes they are very easy to change if you have the right tools.  The rear bearing/hub assembly is about £140 from VW, per side.  You can get much cheaper alternatives from Eurocarparts though, which is probably advisable if you're thinking of selling the car.

[Octoparrot]

Look on YouTube for HumbleMechanic, he's just done a video on changing the rear bearings on a mk5 GTI.

[pudding]

Yeah the Humble one has some great MK5 guides, especially the door module replacement - very detailed.

For the rear brakes, the best tool I can recommend is a stubby spline set to get the carrier bolts out - https://www.amazon.co.uk/Stubby-Impact-Triple-Tamperproof-Sockets/dp/B074QQHC37/ref=sr_1_28?s=diy&ie=UTF8&qid=1537540816&sr=1-28&keywords=spline+socket+set