my car has white smoke out the exhaust when it has just been started and for like 30 min after started, i figured ok its cold outside and cars have white smoke when its cold..today it was 70 and had white smoke...whats wrong, head gasket??

 

Could be
Could be
I had that on my 211,500 mill in my Blazer.
I drove it until I got chocolate milk, then installed the 3.4 I mention below.
I recently started that Blazer (FINALLY!) and took test dive.
Untuned/tweeked right, I enjoyed the new found torque & power. HUGH VICTORIOUS SMILE from me.
Ya can change gaskets & such YET when that point happens (head gasket), current mill in almost outta here.
I was very lucky how far I drove my Blazer with a bad head gasket. Very lucky. Cause when that gasket finally went, engine died instantly.