T4 TDi exhaust rattle

[Seano]

This rattle has been going on for a little while at low revs (especially when reversing). Finally thought about it seriously yesterday and found the rattle. It's in the exhaust system. And it's in the exhaust box/muffler/chamber that sits directly underneath the driver. I assume it's the first chamber after the engine.

What does this chamber do? Is it critical or just merely important?

Obviously something is broken but whatever it is doesn't seem to be impeding performance. Replacing it will cost money but the amount depends on whether I can replace it with a simple steel tube or whether I need the bespoke part.

Comments?

[Silver Caravelle]

Sean,

If it was a T4 petrol, it is the catalytic converter that rattling - and leads to performance issues. In a T4 TDI, it is likely to be the same? Without it, it will be noisier and have increased higher resonance.

A tip: you might be able to pick up a good second hand item from a VW wreckers.

Cheers,

Scott

[melissa]

Mine makes a bit of a rattle from there too but I think it's the heat shield.

[Jmac]

Mine makes a bit of a rattle from there too but I think it's the heat shield.

Heat shield is common,this will vibrate, the cat will sound like a bag of stones if its letting go, especially if you rev it at idle or load up the engine, and as someone has already mentioned it can eventually cause a blockage and hinder the perfomance and maybe even cause a non start condition
cheers
Jmac

[jets]

Replacing it will cost money but the amount depends on whether I can replace it with a simple steel tube or whether I need the bespoke part.
Comments?

I have a friend who does the annual inspections in western Sydney & he says there is an enormous fine if you remove the cat & replace it with a straight pipe, its an EPA thing.
If you do take it out you had better stay out bush.

[Seano]

Your feedback and a bit of a think has led me to believe that the problem is one or more of the heatshields. The cat doesn't sound like a bag of rocks and the rattle that is there has that thin, tinny, alloy sound to it....

Hopefully I'll get a chance to actually look at the problem this week!

[Seano]

Righty ho...

The mystery 'rattle' is definitely in the exhaust system of my TDi...and it is between the manifold and the first exhaust box located under the driver seat.

Hunting about underneath before Xmas identifed that the heat sheild in this area is fine and attached....and that one of the exhaust mounts in the rear had walked off the end of its metal 'stick'. All fixed before the Xmas migration.

Having returned after another 3,000km on the clock....I've established a few things...

Fuel economy and general performance are largely unaffected by the rattle - in fact it essentially disappears at higher revs.

It now has friends....the off side front brake disc protection shield has come loose (thanks to the Waratah Ridge Track in the Newnes State Forest near Lithgow, NSW) and rattles like a bastard! And I suspect that one of the steering rod ends on the same side has a tenuous grasp of the functional as well.

The 150,000 service at the local dealer is looking better and better.......<sigh>

[Silver Caravelle]

Righty ho...

The mystery 'rattle' is definitely in the exhaust system of my TDi...and it is between the manifold and the first exhaust box located under the driver seat.

Hunting about underneath before Xmas identifed that the heat sheild in this area is fine and attached....and that one of the exhaust mounts in the rear had walked off the end of its metal 'stick'. All fixed before the Xmas migration.

Having returned after another 3,000km on the clock....I've established a few things...

Fuel economy and general performance are largely unaffected by the rattle - in fact it essentially disappears at higher revs.

It now has friends....the off side front brake disc protection shield has come loose (thanks to the Waratah Ridge Track in the Newnes State Forest near Lithgow, NSW) and rattles like a bastard! And I suspect that one of the steering rod ends on the same side has a tenuous grasp of the functional as well.

The 150,000 service at the local dealer is looking better and better.......<sigh>

G'day, another suggestion is the shield around the engine down pipe itself. This can rattle at harmonic revs. A screw wedged in the bottom of the shield and pipe should cure it. Otherwise the first exhaust box would be the culprit.

Cheers,

Scott