I have a '94 Pontiac Grand Am with 140k miles on it. The other day I noticed that it took more gas than usual to keep the car moving... when I took my foot off the accelerator, instead of coasting on momentum, the car slowed quickly, almost as if it dropped back down into a lower gear. I know it could be a brake issue, but it just didn't _feel_ like the brakes.
The next day, I noticed that the severity of the problem is proportional to the engine temperature. Not even noticable when the engine was cold, moderate at regular running temp, and difficult to maintain any speed once the temp gague got past the halfway point (220°F).
The fact that it was heating up so soon (again) would have concerned me even without the dragging issue. I ended up stopping to let it cool down, and made it the 4 blocks home without incident.
Relevent History: I had the thermostat replaced ~ 6 mos ago. It wasn't kicking in until about 250° and I had a few near overheats as a result. About 6 weeks ago I brought it into the shop for a check engine light. The diagnostic said it was a problem with the idle air control valve, and they "traced and repaired bad circuit." I mentioned to the mechanic that even with the new thermostat, it seemed like the engine was running hot, but not in the "red zone." He told me that the new thermostat was working fine, but that the dashboard gague was reading about 20° too hot.
Before I bring it in to have this new problem checked (or just replace the car altogether), I wanted to see what the real experts here had to say.... so here I am! Any thoughts, comments, suggestions are greatly appreciated. I'm happy to provide more info, I just don't know what might be helpful to know.
Thanks!
(By the way, in case it wasn't painfully obvious, I'm not much of a do it yourself'er when it comes to my car... I usually leave most maintenance to the professionals.)