Hi all! I've got a newly inherited 240 with about 300,000 miles on it that runs great on the highway but is having problems when in idle. I'm far, far from a mechanic so forgive me if my question is an easy one.

As I said, my car runs great except when I'm idling at a stop sign or at a toll plaza, etc. It will be fine for about 45 seconds but if I sit any longer than that it sounds like the engine is banging against the roof of the hood. If I stop the car and restart it and start driving it runs fine but if I stop again and don't turn off the car while I'm waiting it does the exact same thing. Again, it works fantastic while driving down the road. This actually gets worse in the afternoon when it's hotter (it starts banging a lot sooner than it does in the early morning).

If someone can point me to some things I can check out I would be very, very grateful to you!

Thanks!

 

pop the hood, then start the car. check the movement of the motor. if it starts out smooth then wobbles really bad.....could be a worn mount. rev the engine by the throttle body and watch the motor's vibrations it should smooth out....

maybe video tape the engine then post it.....

wait for the experts to get on.

 

My first thought was at idle there is not enough oil pressure to lubricate the bearings. The oil pick-up screen may be clogged and at low speed cant provide enough lubrication to keep the bearings from banging, but at higher engine speeds there is enough pressure to keep the bearings lubed...I like the idea of videotaping or recording the banging

 

Do you have a mechanical fan on the car or an electrical one for engine cooling.

 

I just checked with my boyfriend and he said it was an electrical fan.

When I get home this evening I can take a video and post it on here.

Thanks!

 

wheres the video?!