Volvo: volvo 960 rough idle, master mechanic, vacuum leak

Question
Relax Ray,
If you are going to call yourself a master mechanic, at least provide something insightful and not reply with something a junior mechanic would say.  I wrote to you because the dealer just does not know.  If you have never experience this type of rough idle, just say so, please don't tell me to force the dealer to pay attention, might as well just write him a blank cheque.  Sorry to have bother you, I'll go away now. Thanks.
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Followup To

Question -
I have a 95 960 with a B6304S engine.  The engine developed a rough idle about 4 months ago in which the whole car shakes and gets worst when taken out of drive. The rough idle sounds like a misfire at the exhaust and only happens when the engine is warm, no issues when it's cold.  Driveability is still fine, no power problems even at 120km/hr.  There are no service lights or codes, the dealer doesn't know the cause and don't want to spend too much time on it.  The spark plugs look fine, no sluge or heavy carbon deposits. I usually have the air conditioning turned off so I don't think it's related to the a/c compressor and I've changed the idle air control and both power stages, no luck.  Any suggestions?  Thank you.

Answer -
Paul,
So I advise you what things make or cause a rough idle and you accuse me of not "reading the question". May I ask what you mean? You say Oh well the plugs look good!!! Good looking plugs that are fouled out cause a missfire. Oh let me see since the car runs out well at speed, you mean there could not be a vacuum leak? I now know why the shop you brought the car to did not want to spend any more time on it.

Answer
Paul,
If there are "Master Techs" looking at your car, and they can not see a problem. You ask through e-mail what I think and receive an answer as to what the cause could be which I supplied, now you would like me to offer a fix for what apprarently is so slight it can not be dectected. Let me offer this, perhaps the injectors are getting slightly clogged causing a misfire and a cleaning would be in order.