funny you should say about the manifold because, when the car has been running for about 2 minutes, from cold, and no longer has the rattler from tart up, it starts to sound like a deisel engine, though tickover and running are still smooth.
Then after about 5 minutes of this it quietens down and sounds normal again, so I was wondering if I had a crack int he exhaust, which was opening slightly, when getting warm and then closing up again.
Also if I have left the car, for 20 minutes, it can sound like a deisel again, for a few minutes.
To me it sounds like two distinct problems, though I am not a mechanic, one the rattle on startup, when cold and two the noise that sounds like a blowing exhaust.
I really need it checking over but no longer have faith in my local Vauxhall delaership
Anyone know of a good mechainc in the Berkshire Area ?
MattP