Strange rattle at idle

[ma77y]

Any one had this? vans driven fine with no issues. Starting it after visiting me ma's and it's making an awful rattle noise, seems to be coming from the timing belt side of the engine. I increase the revs and the rattle goes. took the risk and drove it home with no issues and the engine was pulling strong. Reversing on the drive I heard a little squealing noise that I've never heard before. Rattle seems to be affected by moving the steering wheel left and right.

I had the timing belt and water pump done at vw in 2022 @96,710 miles van is now on 105,010 miles. can't imagine it's that.

Had the auxiliary belt & tensioner changed under warranty in 2021. had a little squealing off it in the winter but nothing since.

The video I've taken is mp4 and unable to upload, I'll try record an audio file tomorrow.

Any suggestions?

 

[Stay Frosty]

Alternator belt tensioner pulley sounds like a tinkling rattle when it's on the way out.
I've got mine booked in in three weeks time to investigate just this with our camper at 59,000 miles now but I had the tensioner pulley and the auxiliary belt replaced a couple of years back so not overly impressed at how that's dying already.

 

[ma77y]

Suppose I could remove the auxiliary belt and see if the tensioner pulley is bad. could also start the engine and check if the rattle is still present or not.

 

[Dellmassive]

Any one had this? vans driven fine with no issues. Starting it after visiting me ma's and it's making an awful rattle noise, seems to be coming from the timing belt side of the engine. I increase the revs and the rattle goes. took the risk and drove it home with no issues and the engine was pulling strong. Reversing on the drive I heard a little squealing noise that I've never heard before. Rattle seems to be affected by moving the steering wheel left and right.

I had the timing belt and water pump done at vw in 2022 @96,710 miles van is now on 105,010 miles. can't imagine it's that.

Had the auxiliary belt & tensioner changed under warranty in 2021. had a little squealing off it in the winter but nothing since.

The video I've taken is mp4 and unable to upload, I'll try record an audio file tomorrow.

Any suggestions?

Drop a link to Ur video here.

Or put it on YouTube and put a link to that here.

If it possible dual mass flywheel?

 

[ma77y]

 

[ma77y]

Louder inside

 

[Dellmassive]

a bit inconclusive from the outside, without any throttle blips, . .

but the inside sound woukld imply there is soumthuing thats transfereing the sound to the chassis . .

loose pipe or somrthing touching the body work?

has it just started?

have you had any work done recently?

undertray wrattling?

++++++

try a new clip with the phone under the engine area facing up. . . then start the engine, some tickover, some throttle blips and a shut down . . lets see if that shows anything?

 

[ma77y]

Yes only just started. no work done recently just services. Engine has no under-tray but I do intend to buy one. I'll try get another video posted up today. cheers

 

[meza]

Yeah be interesting to hear a video with a bit of throttle variation and also steering to lock.

The squealing you described when reversing - is it worse when steering, especially to lock? What about with air con turned on?

These things would all point to auxiliary belt.
The alternator clutch pulley can fail too causing aux belt issues.

 

[meza]

as it has no tray, you might be able to video the belt and tensioner from underneath

 

[ma77y]

My kids are off school now so until swmbo returns from work I'm pretty much tied up. I'll try do some diagnostic later this evening. thanks for your replies.

 

[ma77y]

Successful diagnosis done! turned out to be the alternator freewheel pulley. It appears to be locked up solid. I bought a new pulley for it and using the laser alternator pulley removal tool found that the T50 on the alternator shaft was a lot looser fitting than it should be, one turn and could feel it slipping . I've now got to remove the alternator and either fit a new one or try remove the pulley somehow.

 

[ma77y]

Quick update! Just finished the alternator pulley swap. Turns out it was a spline on the alternator shaft not a t50 torx. Bought the slide pins so I can put the lock carrier into service position and it made the job a doddle for access and pulling the alternator out of the top! Pulley torque was 108Nm going off the INA website.

£40 pulley, 2.5 hours on the drive (alternator out) and the van runs sweet again.

Thanks for all replies.