98 V70XC Engine Noise and Vibration Issue

[jmana]

I have had 4 Volvo 850 wagons before, so I am pretty familiar with them. But I just bought an V70XC that has a noise and vibration coming through the gas pedal and underside of the car that I can't figure out. The car has been maintained very well, the previous owner babied it and spent $$$$ on it. Why he never noticed this issue I don't know, maybe he grew used to it over time? But it's pretty bad. The noise sounds like an exhaust leak. That increases to a loud roar when the turbo kicks in. I checked the turbo and the blades are fine, tight and spin fine. I didn't see any obvious leaks in the pipe, but with the shielding in place it's hard to see, but I can't figure out why a leak would just pop up for no reason? The sound seems to be coming from up high, right behind the dash. The other thing is the car vibrates bad, it's really noticeable through the gas pedal upon acceleration. I looked through the service records and some of the engine mounts have been replaced, and I looked at the others and they "seemed" okay. Any ideas on where I should be looking? I don't suppose these issues are related? On a side note, he had a new radiator put in about 50,000 miles ago, and they put in the right antifreeze. Then he went back 30,000 miles later for a flush, and they put in "green" antifreeze. Said so right on the slip. And guess what? The damn heater core leaks and makes a stink anytime the blower is on. Luckily I found a heater core for $35 new on Amazon, but I've done that job once before, and I don't remember it as being a fun job.

[rspi]

Do you have a CEL?

[jmana]

No engine light.