The first thing that happened around 60,000 or so; intake gaskets leaked and needed replaced. Took it to a few garages because the O2 sensor was throwing a code. They suggested I replace the O2 sensor or two (note this is a Canada model and only has one O2 sensor). I replaced it, but that didn't fix the problem. The car would idle rough from high to low. I found the intakes were leaking with a little spray around the engine while running. I replaced the intake gaskets, taking care of the problem and the O2 sensor code.
Yes the center console lid breaks; a known issue.
Alternator quit working, had a garage replace it for about $400 or so. Lasted about a year and they towed it back to the garage and replaced it again. This happened 3 or 4 times for about $1600. Finally I told them to use an OEM alternator. This fixed the problem other than they didn't fasten the line back to the bracket, causing the line to break and leak into the alternator. They fixed it free of charge that time. Now it's 166000 miles and still working.
Replaced intake gaskets again at about 120,000 miles. These plastic gaskets shrink, causing the leaking problem. Known GM issue, yet they still used a cheaper gasket on different models for years.
Timing belt lasted to about 140,000 miles, longer than it should; wasn't broke, but worn. I replaced it along with the tensioner. The tool for locking the four cams up doesn't work on Canada models, two cams are a 180 degrees out. I made my own tool for the cams.
At 166,000 I noticed oil around the spark plugs, Time to change all the seals. I'm using a generic way for now to stop the oil leaks without tearing the engine down. Working but not sure for how long. Some day I'll probably do a major rebuild, but for now it's running fairly good and strong, other than a low idle and stalling issue at start up.
Note: Only ever replaced one sensor on this car, the O2 sensor, and the one I replaced tested good. O2 and the EGR valve needed cleaned. Most of the sensors can be cleaned, which I have done a few times over the years.
Had problem with tires wearing with only 19,000 miles on them. They couldn't get the alignment right until we oblonged the strut tower holes. Then we got the alignment perfectly on. No more wearing tires out so quick.
The rear trailing arms needed to be replaced; a rusted bad one even broke from hitting a pot hole. Notable corrosion on rear frame parts.
Turn signal lever/cruise control on steering column needed replaced twice. The major cause of this is believed to be the tilting steering flexing the wiring. The last one I replaced with added hot glue to reinforce the wiring.
My Monte is white, and the paint job is peeling down to the primer; a known issue.
Hoping to strip it to bare metal and give it a new paint job. Trying to restore it.
Overall the vehicle has been good; just wish GM would wise up some, or hire new engineers.
The vehicle even goes good in the snow with different tires. Had to experiment with tires for traction.
Doing the maintenance as it should be done makes this vehicle keep running.
Rotating tires every 3-5000 miles, changing oil at 3000 all helps.