Quote Originally Posted by Alexlind123
I was under the impression that all m30's idled roughly when cold, perhaps i am wrong. Also, the head gasket itself only costs ~$100 so i would be saving $900 by doing it myself over a couple of days. I think i may wait a bit longer on this to see if it gets any worse.
I could be wrong, but I think all M30s tend to idle a bit rougher period. If there's a noticeable difference in the idle between cold and hot that's not normal.

BTW, that's how mine was, it would idle rough cold and then smooth out when warm. What was happening was when it heated up it would seal up the coolant leak. When they tested for exaust in the cooling system when it was warm there was no sign of it.