hey guys....

i have a 2002 tl-p and it has about 45k miles on it...just today i noticed that the car idles kinda rough. when it's fully warmed up, it idles around 750rpm and then when the radiator kicks in, it'll jump up to 1000rpm. i noticed that radiator fans do not stay on, they turn on and spin at full speed for a second and then they slow down and the process repeats. as this is happening, the rpm meter is bouncing between 750-1100rpm. when the radiator fans are constantly on at full speed, i do not feel this problem, nor do i feel the problem when the fans are not on.

another thing i noticed is that the interior lights will dim when the rpm is fluctuating (alternator problem? not sure..hence, this post).

some history about my car....it was in a front end collision (this past summer) and the radiator was replaced along with one of the radiator fans...i'm not sure if it's the radiator problem or if it's a problem with a clogged egr port. i read searched for similar issues and most people cleaned their egr ports and their rough idling problem went away.

i also noticed that the top piece on the coolant reservoir moves around freely, like it can be pulled out and put back in...i'm referring to the plastic piece that's attached to the black hose. is it supposed to be like that?

please let me know what you guys think. thanks.