I thought I would post my latest issue just to see if anyone thinks it is a problem.

My daily driver is an 89 300SE, and it has been just about perfect since I got it a couple years ago. However, it acted very strangely today. After puttering around town at lower speeds today for maybe an hour, I got it out on a less travelled road, up to about 50mph, and it wouldn't go into 4th gear. It was revved pretty high up for such a speed, like 3K+, and it wouldn't go into 4th. I then stopped at a light, and got back on to another road and tried the same thing. Got it up to 50mph, high revs and no 4th. Then I stopped the car, put it in park, then put it back in gear and accelerated fairly hard...and it shifted fine, 4th came somewhere around 40mph. I drove it for a few mins after that, accelerating normal and hard up to 60-70mph, and it shifted pefectly.

Is this a sign of an impending transmission blowout, or an electrical issue in the regulation of the shifting, or is it just a weird thing that happens on a 15 year old car? Any thoughts would be welcomed.