Caddy Maxi issue DSG? Help please

[Panada83]

Hi folks,
Wondered if I could pick your brains on a issue with my van.
It's a 2012 vw caddy maxi c20 that's a 1.6 diesel with a DSG gearbox.

For quite some time now the vehicle has what I can only describe as an intermittent problem.

Every so often, like maybe a 2 or 3 times a month, suddenly while driving the tone of the engine changes, a deeper tone. The vehicle also appears slightly less smooth/sluggish between gear changes. A smell that is quite pungent enters the cabin, maybe a bit like oil burning or like somethings hot. And also sometimes while its entered this state it will do a jumping/juddering when reversing and sometimes when crawling at a busy roundabout, when you edge forward (maybe a little bit heavy footed) you hear the most disturbing noise of all which sounds like, some kind of belt slipping or something.

Very strange. I've tried to describe this as best as I can. I guess that's what intermittent problems are like.

But then for 95-98% of the time the van is absolutely normal...

Has any one got any ideas.

Very much appreciate your comments

Nathan

[Panada83]

Thanks for replies.

If it was the DSG gearbox would the engine sound have that deeper tone I mentioned. Almost as if the engine has something wrong with it?

Sometimes the vehicle does it when it has been used very little in the day - could the gearbox oil and clutch plate get so hot so quickly after little usage?

Nathan

[Panada83]

Thanks but would EGR bring a smell into the cabin? And sound at times like there's a strimmer under the bonnet?