The typical things that go wrong with the 3rd gens:
The oem window regulators break. The one he's looking at probably has had
most replaced by now.
Coolant temp sensor deteriorates and gives a bad signal. Very easy to fix.
When changing the timing belt, the water pump and thermostat should be
changed.
Lower control arm bushings are probably ready to replace. Buy the entire
control arm instead of trying to extract and replace the original ones.
Front struts and mounting hardware.
Fuel injectors might start going bad. Usually they are intermittant for a
while and then go bad for good. A somewhat difficult job for a DIY but saves
a lot of money.
The transmissions in these start to go out around 120k to 150k. Sometimes
sooner, sometimes later. I've had both my 90 & 94 rebuilt and they run
great.
The digital clocks go dim and then sometimes just quit. You can get these on
Ebay for around $25.
Sometimes the exhaust Y pipe corrodes where the 2 pipes come together. You
may see a bunch of rust on the muffler casing. Don't be alarmed! This is
just the outside shell that rusts. The muffler is usually still good and
will last several years. Both mine are rusted through the outside shell and
they work just fine.
Sometimes the shift lock controller goes out and you can't get it out of
Park without releasing the button.
The Bose and Clarion stereos' amplifiers usually are toast by now. Remove
all speakers and in-dash unit and replace with aftermarket stereo and
speakers.
The hi pressure power steering hose will start leaking at the upper banjo
bolt connection.
The exhaust manifold studs break due to heat corrosion and expansion. Mine
haven't but I've heard of others that have. A bitch of a job to fix.
The little plastic/rubber shift linkage grommet deteriorates and makes
shifting into gear real sloppy (automatics only). It's a $2.00 part and you
have to get up under the car to replace it. Not too hard if you have hi-lift
jack and jack stands.
My cruise control computer is out in my 90 and I can't seem to get a
replacement unit that works. New one's are ~$400 so I've tried using Ebay
parts but I can't get one that works so I gave up. My 94 cruise control
works just fine.
The rear lights tend to get bad connections where the bulb meets the
connector. They need to be cleaned and check every few months.
All the small vacuum hoses are probably brittle and will need replacing
eventually if you have to replace any fuel injectors.
The alternators and radiators are known to go bad at this age.
If you live near Dallas, your son could buy my '90 GXE!!!! See my ad:
http://www.cars.com/go/search/fsbo_s...liate=da llas
Good luck!
Chris
90 & 94 GXE's
06 SE