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I Just Need To Know How Do You Find Out What Type Of Coolant My 2002 Sierra 1500 Takes Or If Anybody Knows The Type And Can Tell Me That...

I Would Like To Add Antifreeze To My Alero. The Cap Says Only Use One Type Of Antifreeze. If I Don't Drain It, Do Have To Use That Type...

What Kind Of Antifreeze Should I Use In The Rad. Also Temp Is Coming Up But When It Idles Cool Heat. Thanks Dan