170 4Mo whining/grinding sound

[hotmetal]

Hi fellas. I've got a 2010 Tiguan 4 motion 170bhp 2.0 tdi. It's got almost 90k on it.

I got it back in January and had the cam belt done and at the same time got them to change the oil in the 4 motion Haldex unit.

I've noticed for a little while that at motorway speeds there's a slight whining noise that starts becoming audible at 70, and rises in pitch upto about 90. It's speed related rather than revs. Yesterday it started getting louder, and more 'grindy' than whiny so I'm getting worried. You hear the noise under acceleration or constant throttle but It stops briefly when you take your foot off the gas. When it's under engine braking it comes back.

Any ideas? Gearbox? 4 motion? Just the oil in either of these or is something about to go bang?

[Rob69]

get the haldex and diff oil level checked, I've read of folks who've had the haldex and diff drained and filter changed then only had the haldex refilled.

[hotmetal]

Cheers Rob, makes sense. I hope no damage has been done. Will get it booked in somewhere other than the place that did the oil change and get them to check as you suggest

[hotmetal]

Quick update. Just for anyone else who has this problem in the future. @Rob69 you were spot on. The garage undid the wrong drain bolt and as a result the diff had no oil and the Haldex twice the quantity. The result was a total write-off of the diff and haldex. Parts and labour over £4k so be warned!

I'm happy to say that the garage who made this mistake (I won't name them) have been very good about it and were properly insured so their insurer is paying for a main dealer to replace.