Up to 250,000 km everything was perfect with the exhaust, but now over the past 3 months a rumbling/buzzing sound has appeared from the exhaust.

The exhaust is not hollow, there are no leaks anywhere…

I’m wondering how this could suddenly happen. When driving in 6th gear and pressing the gas pedal all the way, it sounds as if the exhaust is hollow, meaning a deep tone…

Also, a very unpleasant sound is heard when pressing kickdown and the car shifts back into 4th gear.

What should be done?

Both exhaust clamps have been newly installed.

2.0 TDI 4x4 125 kw CFGB Engine

A simple possibility could be one of the heat shields has dropped down.

They are thin aluminium sheet and will create a buzz/rattle if loose.

Worth checking from front to back.

The clips rust through and can be replaced cheaply. I had this at the rear of my car.

Also the exhaust sleeve in the middle of the system became loose, the clamps had rotted and it needed replaced.

Hopefully be something simple.

On 30/03/2026 at 10:08, TasMan said:

A simple possibility could be one of the heat shields has dropped down.

They are thin aluminium sheet and will create a buzz/rattle if loose.

Worth checking from front to back.

The clips rust through and can be replaced cheaply. I had this at the rear of my car.

Also the exhaust sleeve in the middle of the system became loose, the clamps had rotted and it needed replaced.

Hopefully be something simple.

I installed two new clamps on the exhaust.

I checked the heat shields around the exhaust and the clips — they have no play or movement.

Can the rear muffler burn out from the inside or not?

P.S. I am the second owner.

The car was purchased in Bosnia and Herzegovina in 2015, and it has the original 240,000 kilometers.

Edited 2 April2 Apr by WarppeR

Anyone ? Ideas?

Its possible the silencer is double skinned and the inner has gone but its normally the other way round. It may have baffles in box that have come loose. If its the original exhaust it may be failing.

Alasdair

3 hours ago, Alasdair1 said:

Moguće je da prigušivač ima dvostruku oblogu i da je unutrašnji dio nestao, ali obično je obrnuto. Moguće je da su pregrade u kutiji olabavljene. Ako je u pitanju originalni auspuh, moguće je da ne radi ispravno.

Alasdair

I’ll try to find a used exhaust at a scrapyard to test it.
I’ll update the post once I do that.

A friend had similar problem. Car didn't sound right and engine was way down on power. I noticed strands of what looked like hair coming out of rear tailpipe. First we thought a small animal had crawled in and partly blocked it so we pulled it out and it kept coming and kept coming. Weird looking stuff like long hair. The internal baffles on exhaust had rotted out and allowed the fibreglass to come out of tail pipe. New exhaust and back to normal.

Alasdair

42 minutes ago, Alasdair1 said:

Prijatelj je imao sličan problem. Auto nije zvučao kako treba, a motor je imao znatno smanjenu snagu. Primijetio sam pramenove nečega što je izgledalo kao dlaka kako vire iz zadnje auspuha. Prvo smo mislili da se neka mala životinja uvukla unutra i djelomično je blokirala, pa smo je izvukli, a ona je nastavila dolaziti i dolaziti. Čudno izgledajuće stvari, poput duge dlake. Unutrašnje pregrade na auspuhu su istrunule i dozvolile su da fiberglas izađe iz auspuha. Novi auspuh i povratak u normalu.

Alasdair

I will try with used exhaust fr

47 minutes ago, Alasdair1 said:

A friend had similar problem. Car didn't sound right and engine was way down on power. I noticed strands of what looked like hair coming out of rear tailpipe. First we thought a small animal had crawled in and partly blocked it so we pulled it out and it kept coming and kept coming. Weird looking stuff like long hair. The internal baffles on exhaust had rotted out and allowed the fibreglass to come out of tail pipe. New exhaust and back to normal.

Alasdair

Great, I’d be overjoyed if the last muffler on the exhaust had gone 😀