In 2003 I bought a '97 Bonnie without doing much research. Afterward, I heard about the plastic IM and potential issues with the gaskets, and Googling around convinced me that my motor was going to explode soon, probably the next time I drove it. Haha.
Anyway, I went to my local mechanic, and he hedged on it a bit, but said it wouldn't hurt to replace the stuff, as the car had 90,000 miles on it. He'* very reasonable price-wise, so I decided to take no risks, and have him do it. After that, I drove the car another 100,000 miles with no major engine trouble. So all was good, I guess, but I have to wonder if I was being overly cautious.
Fast forward to my "new" 2002 Bonnie, which I got a week or two ago. It'* got 120,000 miles, and I have no service records. It was well cared for and looks clean inside and out. My question is, how much should I worry about this problem on a 2002? Is it different than a 1997 in significant ways? While I have done a small amount of research, it'* still not clear to me what the actual defect is. Is it the IM itself? A specific gasket? Both? Did GM improve the situation between 1997 and 2002?
I don't want to make any hasty decisions this time around....maybe I should just watch for leaks externally and check the oil frequently? Spending a few hundred bucks to significantly decrease my chances of engine trouble in the next 50,000 miles or so seems like an OK idea to me, but I guess I shouldn't spend money now that I would be fine spending later, or never, if I was safe simply monitoring the situation. I don't drive my cars hard at all (my wife says I drive like an old man); I put on maybe 12-15K miles per year, mostly between home and work (~15 miles one way). Occasional trips of a couple hundred miles, no plans to depend on it for a long road trip at this point.
Like I said, I have done a bit of research, but it'* been spotty, and a perspective from owners of this motor would be very helpful, and very much appreciated.