Two things are happening to my Lanos. First, the engine is fairly loud and seems to be at fairly high RPM in idle (1.5K - 2.5K, IDK, Don't have Tach). Second, when I'm stopped at a light, my engine heat goes up, but not into the danger mark, then when I resume driving, it returns to normal. This has never happened before. I feel pretty confident saying that this isn't a mechanical problem, I have checked all the vaccum hoses, oil, coolant, etc. But all seems normal. Could these two things be a sensor issue?
These two are in the running for the bad sensor. Coolant Temperature Sensor, and O2 Sensor. (Neither have been changed in 6 years or 180K miles.) Is it possible that these two are the issue, or is there something else. What are the "symptoms" of a fouled CTS or O2S? And where is the CTS located?
Thanks all.
Damir.