KA24DE runnin hot, but not showing it. help plz

[punkrocker7788]

This has happened for a while now.. Ive been driving my 93 240 around, has the KA24DE. While Ive been driving and after it gets warm I can smell a burning smell, almost like the oil is getting too hot, but when I go to check it... its fine. No loss or anything. I use 5w-30 royal purp. I went outside to check my spark plugs and they were white, signs that the motor is runnin hot, but while Im driving it the temp gauge stays in the middle. never goes higher.. I dont have a clue what is wrong and need some opinions please. Gracias.