i'm a newbie to this forum , and i would like to ask you guys for help.
i have a w 202 based c 180 (65000km on the clock). a few weeks ago i had an over heating problem, it turned out that my visco fan needed replacement so i have i replaced. the problem was solved.
last week i had an oil change, i normally use mobil super s but since i was on vacation and the shop didnt sell mobil 1 products so i used petronas synthium because i read that it has MB certification.
but now everythime i got on the freeway or climbing up some steep road the temperature would rise to over 110 degrees (centigrade) it even went on to 120 on some occasions. when i'm back to level road it will drop back to around 90-100.
i tried replacing the radiator cap, checked the auxiliary fans and they turned out to be okay.
what's the problem wiht my car.
ps: i always use 95 octane gas.
help please