Knocking from the back? W203 estate

[britnordic]

Hi all
over the past couple of weeks I've noticed a knocking sound from the back as if the exhaust pipe is making contact with something. This only happens when the engine is cold (hence suspected exhaust) but is louder when fuel tank is half full or lower.
The silencer box seems rigid and cant see anything loose, perhaps I need a ramp? Any ideas?
Thanks in anticipation..

Tony

 

[television]

Is the banging in sympathy with the road speed

 

[britnordic]

Hi Malcom
not really, just moving off from start and seems to be there till I reach the dual carriageway, approx 2 miles, then gone !!!
Should qualify that if I put my foot down imediately after starting, you can still hear it. But as with all my diesels, I can't stand the sound of the engine when cold, so usually take it easy for a couple of miles.
Tony

 

[television]

I am blank for the minute on this, lets see if someone else picks up on it

 

[jibcl500]

Tony

Its not those cheap tyres you bought going lumpy on you is it???

jib

 

[britnordic]

Hi Jib
no dont think so, she steams along without any vibration!
Might have to pay you a visit!
The lumpy ones were the original Dunlops!

Tony

 

[television]

Some cheap tyres can get flats on them, this does not affect the balance but they can be felt in the car

 

[britnordic]

Khumos again ! A few thousand on them now, but feels smooth. The Dunlops went out of shape, probably due to age, as I bought the car with 30k up in summer of 2007. (Registered in Jan 2003!!).
On the second set of Khumos at nearly 90k now.

Tony