C5 wanted a list of common exhaust leak areas.

[cachaciero]

Over the last few days have become aware of an acrid smell in the cabin, usually only when stationary, could be exhaust gas quite: noticable under bonnet apparently stronger at the back (closer to EGR and Turbo .

Can't see anything obvious so best guess welcome, would like to know if there are any known common leakage points.
This is a 2.2.

cachaciero

[Lighty]

Nothing common as such, how about the FAP pressure pipes ?, there is also the front flexi hose , but never had a problem with one.

[myglaren]

Injector seals/washers.
If you listen while the engine is idling you may hear it 'chuffing' and there may be soot or what appear to be tiny pieces of coal near the injectors.
The copper washers burn away after a while. I've had mine done twice, apart from when the injectors have been out for refurbishment when they were replaced as a matter of course.
Inexpensive replacement.

[cachaciero]

Injector seals/washers.
If you listen while the engine is idling you may hear it 'chuffing' and there may be soot or what appear to be tiny pieces of coal near the injectors.
The copper washers burn away after a while. I've had mine done twice, apart from when the injectors have been out for refurbishment when they were replaced as a matter of course.
Inexpensive replacement.

What a wonderful description of the problem!

Removed the rear top cover and all was revealed exactly as described, the only addition to the chuffing, not really audible with the rear cover on, was the stream of smoke emanating from the defective seal.
Problem resolved in a fashion will put more details and observations under a new post, any cheers was a good call.

cachaciero