annoying squeal/squeak on a 06 plate Gti

[fliprio]

Evening all,

It’s one of those strange noise threads again!

While driving along without touching the brakes I get what sounds like some brake squeal which chirps for a couple of seconds and goes away.  Generally a slight turn to the right or left can make it happen more often and when I let off the throttle it also seems to occur more.  It also only happens after ~7 miles, not from cold

Thinking it was the brakes, for the sake of 30 quid I rebuilt the front calipers seals, guides etc and found it had a rear sticky caliper which I have replaced but still the noise!
It doesn’t seem to do it on the motorway but does do it at 50-60 or lower speeds and sometimes I swear I can hear a faint continual sqeak.
It’s a rotary squeal not a momentary squeak which is why I have ruled out suspension etc but it’s starting to get quite annoying!

Anyone got any ideas on how to diagnose what it is?


Cheers
Dan

[fliprio]

oh, the only additional thing is that it started soon after I replaced the CV boot, whole drivers side shaft came out etc

[fliprio]

alternator clutch pulley checked - works fine, aux belt looks good and seems to be at right tension

its not the 'birds in my engine' cambelt tensioner noise and is intermittent

[Mitch H]

My Mrs has what sounds like the same noise on her scirocco and it's annoying as hell but don't know for sure what it is

[lukemk5gti]

Could be a lightly sticking caliper

[fliprio]

I have pinned it down this afternoon to it happening every time I lift of the throttle sharply once its up to temperature, it them gives a chirp and goes away.

PCV valve?

[fliprio]

Could be a lightly sticking caliper

I rebuilt both front calipers yesterday afternoon as that was my first thought, but no its still making the noise!

[fliprio]

out driving this evening, although it happens generally above a certain RPM the squeak isn't road speed related - same pitch at different road-speeds and happens at different RPMs, but usually when letting off.

When I had the bonnet up this morning doing the test on the PCV valve by taking the oil cap off it did the usual rough running like it should but then I could hear an escape of air when the engine was turned off, not a squeak but you could hear something depressuring itself.

[ChazGTI]

out driving this evening, although it happens generally above a certain RPM the squeak isn't road speed related - same pitch at different road-speeds and happens at different RPMs, but usually when letting off.

When I had the bonnet up this morning doing the test on the PCV valve by taking the oil cap off it did the usual rough running like it should but then I could hear an escape of air when the engine was turned off, not a squeak but you could hear something depressuring itself.

Try and get a video of this? It sounds like you're experiencing a problem that would be picked up by the ECU. Do you have access to VCDS/VAGCOM?

[fliprio]

It looks like a new PCV valve has cured the main squeal noise, the check valve in it looked a bit stuck, its also helped the cold start idle as well.

[fliprio]

Despite getting rid of my main loud squeal (the PCV valve), it seems I have a faint background squeal somewhere from the drive train, the curse of listening out for things when you have fixed them to uncover another problem! 

Once the car has a few miles on it ~10 you start to hear a squeal at 30-50mph, much more than 50 and there is too much road noise to hear it and generally only when the windows are down.

Touching the brakes doesn't get rid of it, putting it into neutral doesn't change it so im a bit stumped as to what to do.

The only thing I can think of is that I recently did the driver side outer CV boot so the whole shaft has been off, has anyone had any wheel bearing issues after undoing the hubnut?  can wheel bearings squeal like this?

[lukemk5gti]

I never had noise after doing my CV.

Did you 100% remove, clean and replace with new grease? How long was the boot split? Maybe the actual joint started to wear down if there was no grease left and now it's grinding.

[fliprio]

I never had noise after doing my CV.

Did you 100% remove, clean and replace with new grease? How long was the boot split? Maybe the actual joint started to wear down if there was no grease left and now it's grinding.

it started to crack on the small end of the boot so it didn't chuck all the grease into the arch and get much in it.

Took the whole thing apart, cleaned it all up with degreaser and took the ball bearings out and regreased everything. 

Its more of a squeal than a metal grinding sound