Hello Jesse:

Do you have emissions testing where you live? If so, this will provide you with objective data on the condition of your car. High NOx would suggest vacuum leaks or a bad cat.

Any evidence of rich running? Dark tailpipe, gassy smell, etc?

Have you checked the function of the 02 sensor with a voltmeter?

What is the condition of the ignition components? Cap, rotor, wires and plugs-- the cost of everything but the plugs is a little distressing on the B280F... Baselining all this stuff removes a lot of variables and allows you to diagnose things with greater confidence.

Flush the coolant right away-- the aluminum block in this model is unforgiving when it comes to corrosion.

I liked my '89 760GLE, although it was a little thirsty-- not that my '92 945T is much better...

Good luck!

--
Herb Goltz, Aurora, Ontario, Canada '92 245 w/124K mi, '92 945T w/200K mi