I looked at the temp gauge in the car again - the temp is not getting much above 60C on even medium-duration trips, and the fuel economy is really taking a hit.

I'll replace the thermostat soon - JJ thanks for that great write-up. If you ever need to remove the valve covers on the same engine, please don't hesitate to ask for help. Lots of little helpful hints, that i unfortunately had to learn along the way, will help turn it from an all-day job to a few hours.

Troy
1995 E420 105k