After getting my rough start issue fixed (rumbling on cold start), I still have a high idle when I start my car. It revs to about 1.5k rpm for a bout 30 seconds and then goes to about 750 rpm. This happens at all times during the course of the day. Is this normal? Or is it part of the rough start issue?

 

Depends on the temerature when you start the car. Does it happen all the time or only on a "cold" start?

 

higher than usual RPM is due to initial/cold starts on most cars. But if a car is already warmed up and started it should not be doing so.

 

Im pretty sure it does it all the time.

 

When cold, my 550 starts up and surges to only about 1,000-1,100 rpm for 10 seconds or less and then rumbles down to about 750 rpm.

I've never seen my engine start up at 1,500 rom and stay there for a half a minute.

Your experience is certainly different than mine.

 

Same here ... no idling surge at 1500. Mainly 1000 - 1200 rpm on a cold start, then to 750 after about 15 seconds. Then when the car's already warm, idle is 750 with A/C on (and with accessories off if clutch is pressed while stopped); 500 with all accessories off (with clutch released and car in neutral).

 

I think you guys are right, its about 1200 for 10 secs or so. I guess then its normal. I will have to wait and see what it does when the temp. goes up outside.

 

I get that too, but only on cold starts. Do you usually start driving right away or do you wait until it goes down to around 750?

 

I usualy wait, till it drops..

 

same here only for cold starts, expecially after not driving it for a while.. but it rumbles at that rpm only for about 10 seconds or so, as said by tachyon.