Recently my 92 Deville started spewing coolant out of the heater vents onto my floor mats, and the windshield fogs up. I figure the heater core has finally sprung a leak, after all these years. I am fairly confident that I can replace it myself. However, my factory service manual does not seem to show many pictures or illustrations. I am just wondering how much of a job it is going to be. A mechanic quoted $400 ballpark cost. Any input will be most appreciated.

 

i think its the same as my 95 deville i didnt know how to either a year ago. i had pictures but i guess i threw them away. it wasn't so hard it took me like an hour cuz i didnt know how. u have to go from the bottom under the glove box but u also have to take the glove box off so u can get to some bolts but the heater core comes out from the bottom.
if i can find the pics i will scan them and upload them.

 

A belated thanks for the advise on the heater core replacement. It was not as bad as I had imagined. The hardest part was disconnecting the factory clamps on the engine side of the firewall. They were impossible to get to. Finally a friend advised breaking the heater core loose from inside the car...sure enough that worked. The old heater core end was made of plastic on the hose connection end. The plastic was so old that it broke loose at the hose connections. Then I could just pull the plastic thru the firewall and remove the hose. Overall, not too bad of a job to do in an afternoon. Figure I saved at least $500-600 by doing the job myself. I hope this will help someone else in a similiar situation.