The head gasket on a GM model, 3100 SFI VG engine may blow because of engine overheating problems. A head gasket can be replaced without enlisting the help of a professional mechanic, but it will require time and patience to dismantle the the top portion of the engine, which is where the gasket sits. If you suspect that your vehicle's head gasket is damaged, contact a your local GM manufacturer to order a head gasket specific to your GM model.
Park your GM model vehicle and shut down the engine. Pop the hood.
Disconnect the negative cable from the battery; use a socket wrench to loosen and remove the bolt that secures the cable to the battery. Lift the battery unit out and set aside.
Locate the car's radiator. Position a tray underneath the radiator and remove its pressure cap and drain plug to initiate coolant drain.
Once the coolant completely filters and out, replace the radiator's pressure cap and drain plug.
Disassemble the top portion of the engine to access the head gasket. Dislocate the nuts that secure the engine's top cover with a socket wrench and set aside. Loosen the bolts that secure the distributor -- positioned next to the vehicle's cylinder -- with a socket wrench.
Remove the cylinder head inside the internal combustion engine by unbolting its nuts; it will be set on top of the cylinder block and spark plugs. Loosen the nuts attached to the valve cover with an adjustable wrench.
Lift the damaged head gasket from the top of the cylinder block. Clean residue from where the gasket was positioned with a scraper.
Position the replacement head gasket inside on top of the cylinder block. Replace all engine components and the battery back into place, re-tightening all bolts or cords.
Replenish the radiator's cooling system. Add in coolant fluid to the appropriate level as specified in the your model's owner manual. Insert a funnel inside the radiator's fill hole, adding coolant to the reservoir. Start the engine and run the car for 10 minutes. Replace the radiator fill cap.
