M50 boominess

[stu1]

Hi Guys,
My M50 ('94 vanos) gets a little 'boomy' between 2500 and 3000 rpm's. Above or below this the booming goes away. In addition if I have it in neutral and just rev it up to about 2700 rpm and hold it there it seems to be a little unstable; it hunts about the revs a little bit. It's always had a slight boominess at about these rev ranges but just lately I swear it's a little louder than normal. My thoughts are it's my exhaust which is getting a little long in the tooth at 10 years old but the sound def seems to be coming from the front/engine.

Is this normal in these engines; am I being a little too perfectionist/paranoid or does anybody know what the problem is likely to be?

One last bit of information, last weekend I had the oil changed; previously it's had Mobil 1, but this time the dickheads stuck in a semi; could this have anything to do with it?

TIA,
Stu.

[Karl]

M50 exhaust does make some noise. Looking through the pile of receipts that came with my car showed PO changed the muffler twice in 85,000 miles. I think the third one is starting to sound pretty good about now. One man's noise is another's music.