overheat problem please help
 

Hi guys I'm going through some issues with my 7.
It's an S4 NA 170k miles, when I start him up his idle bounces from 1500 to 2000 rpms. that lasts until the engine is warmed up, then he drops down the idle to 1200.

About a week ago I overheated the engine on the freeway. As soon as I saw the temperature rising pass normal I pulled over to the side of the frwy and waited for about 45 minutes till the temperature came down completely and I added some more water. The car started with no problems.
Next day I checked the car for oil and water, added some and took it for a spin. Unfortenatly about ten miles from where I live the car started heating up and it was the same all over. But this time it flooded as well.

I started it back again and this time I took of the thermostat thinking that it might help.
I was probably five miles away from home and the thing started boiling again.

Please help, I'm trying to figure out if flushing the radiator will help.
And did any of you guys had inconsistant idling......what fixed it?

There's no white smoke coming out of the exhausts, actually only a little when I start the car but I think thats normal.

Thanx

Start with the basics. Radiator, thermostat, fan and such. Usually if it overheats when driving it at a steady speed it is a problem with the thermostat because the fan isn't doing much at that point. The idle problem could be a lot of things, but you should be able to find something on here. It should be at 750+-.

Thanx 1sweet7.....
I started the car today, and no smoke at all... :)

I need to change my whole exhaust system...I'm thinking the idle dance my be the cause of bad exhaust ( bad cats)

Happy Thanksgiving !!! :o)