This is a general overview; the exact steps may vary slightly depending on the specific engine (likely a 2.2L or a 2.4L). Always consult a repair manual specific to your Sunfire's year and engine for detailed instructions and torque specifications. Improper torque can lead to engine damage.
I. Preparation:
1. Safety First: Disconnect the negative battery cable. Wear safety glasses and gloves. Work in a well-ventilated area.
2. Gather Tools and Supplies: You'll need a comprehensive set of tools, including various wrenches (metric), sockets, screwdrivers, a torque wrench, a head gasket set (including the gasket itself, head bolts, possibly new valve cover gasket), coolant, engine oil, antifreeze, sealant, jack stands, and possibly a hoist. A repair manual is crucial.
3. Drain Fluids: Drain the engine coolant, engine oil, and transmission fluid (if applicable).
4. Disconnect Components: Disconnect various components connected to the engine, including the intake manifold, exhaust manifolds, wiring harnesses, fuel lines (be extremely careful with fuel lines!), sensors, and accessories. Take pictures as you go to aid reassembly.
5. Remove the Timing Belt (if applicable): This is essential to avoid damaging the timing belt and potentially the engine. The procedure for this varies greatly by engine. Consult your repair manual.
II. Head Removal:
1. Remove the Cylinder Head: Loosen and carefully remove the cylinder head bolts in the correct sequence (as specified in your repair manual). This is crucial to prevent warping the head. The head is heavy; use a suitable hoist or engine support to lift it.
2. Inspect the Head and Block: Carefully inspect the cylinder head and engine block for any damage, cracks, or warping. If damage is found, these parts may need to be replaced or repaired before installing a new gasket.
III. Head Gasket Replacement:
1. Clean the Surfaces: Thoroughly clean the mating surfaces of the cylinder head and engine block, removing any old gasket material, debris, or sealant. Use a scraper and a suitable cleaner.
2. Install New Head Gasket: Carefully install the new head gasket, ensuring it's correctly aligned.
3. Install the Cylinder Head: Carefully install the cylinder head, ensuring it's properly seated.
4. Tighten Cylinder Head Bolts: Tighten the cylinder head bolts in the correct sequence and to the specified torque using a torque wrench. This is incredibly important; incorrect torque can cause head gasket failure or even crack the head. The sequence and torque are found in your repair manual. Often this involves several passes with increasing torque.
IV. Reassembly:
1. Reconnect Components: Carefully reconnect all the components you disconnected earlier, referring to your pictures and the repair manual.
2. Refill Fluids: Refill the engine coolant, engine oil, and transmission fluid (if applicable) to the correct levels.
3. Start the Engine: Carefully start the engine and check for leaks. Watch the temperature gauge closely. There's a chance for leaks initially even after a correct job.
V. Post-Repair Checks:
1. Leak Check: Carefully inspect for any coolant or oil leaks.
2. Temperature Check: Monitor the engine temperature.
3. Compression Test (recommended): A compression test ensures the cylinders are sealing properly.
Again, this is a simplified overview. Replacing a head gasket is a complex and potentially expensive repair. Using a repair manual specific to your 1995 Pontiac Sunfire is absolutely necessary. If you lack the experience or tools, take your car to a professional mechanic. The cost of making a mistake far outweighs the cost of professional repair.
