Technical Rough running at medium speed

[smart51]

An addendum to this discussion to finish it off. I replaced the exhaust today after a piece of the old one fell off. Looking at the pattern of rust around the breaks, it seems that the weld between the header pipe and the can has been failing for a while now. With a new exhaust fitted, all remaining traces of vibration have gone away. The car is transformed. It seems that the exhaust was causing vibration and the engine mount was transmitting it to the body. With both fixed, the problem is cured.

 

[the hobbler]

An addendum to this discussion to finish it off. I replaced the exhaust today after a piece of the old one fell off. Looking at the pattern of rust around the breaks, it seems that the weld between the header pipe and the can has been failing for a while now. With a new exhaust fitted, all remaining traces of vibration have gone away. The car is transformed. It seems that the exhaust was causing vibration and the engine mount was transmitting it to the body. With both fixed, the problem is cured.

Delighted to hear that all is now well; but it just goes to show how difficult it is to correctly diagnose a problem "from afare"!