my beautiful 400SE has been experiencing a rough idle for about 5 minutes AFTER it's warmed up. It idles very rough, sometimes stalls, for 3-5 min's after the engine is warm and then runs normally again. Any suggestions on what this could be?

I might add, the car is driven very little, so it sits for weeks at a time. Might this have something to do with it.

Thanks, steve

 

the problem happens after the warmup phase. air leak/restriction.

the engine is shaking? rough idle?

clean idle speed air valve and throttle valve.

check air intake leak.