However, if you are experienced and prepared to proceed, here's a general overview of the process. Specific procedures will vary slightly depending on the engine in your particular Lemans (year and engine size matter significantly). Always consult a repair manual specific to your vehicle's year and engine.
Before you begin:
* Consult a repair manual: A Haynes or Chilton manual for your specific year and engine is essential. It will provide detailed instructions, torque specifications, and diagrams.
* Gather tools: You'll need a variety of tools, including wrenches (metric), sockets, ratchets, a timing belt wrench (possibly), jack stands, jack, pulley puller(s), possibly a crankshaft holding tool, and a new timing belt kit (this usually includes the belt, tensioner, and water pump).
* Safety first: Disconnect the negative battery terminal. Wear safety glasses and gloves. Work in a well-ventilated area.
General Steps (These are generalized and may not apply to your specific Lemans):
1. Preparation: Drain the coolant, remove the serpentine belt, and disconnect any components that interfere with access to the timing belt (e.g., power steering pump, alternator). You might need to remove some accessory components for better access.
2. Access the timing belt: This often involves removing the timing belt cover(s).
3. Mark the timing belt and crankshaft position: Critically important! Use paint marks or alignment tools to precisely mark the position of the crankshaft pulley, camshaft sprockets, and the timing belt itself. This ensures proper timing after reassembly. Misalignment will cause engine damage.
4. Remove the timing belt tensioner: This usually involves loosening a bolt or using a special tool. Release the tension on the belt to allow for removal.
5. Remove the old timing belt: Carefully remove the old belt, noting its routing.
6. Inspect components: While the belt is off, inspect the tensioner, water pump, and other components for wear or damage. Replace anything that's worn or questionable. A new water pump is often recommended when replacing a timing belt.
7. Install the new timing belt: Install the new timing belt, ensuring it's properly seated on all pulleys and sprockets. Use your marks to align the belt to the crankshaft and camshafts.
8. Install the timing belt tensioner: Install the new (or refurbished) tensioner, tightening it according to the specifications in your repair manual.
9. Reassemble: Reinstall all components you removed in the reverse order of removal. Pay close attention to torque specifications for all bolts and nuts.
10. Refill coolant: Refill the coolant system and check for leaks.
11. Check timing: After reassembly, double-check your timing marks to confirm everything is aligned correctly.
12. Start the engine: Carefully start the engine and listen for any unusual noises. Check for leaks.
Again, this is a generalized overview. The exact steps and tools required will depend on the specific year, model, and engine of your Pontiac Lemans. Using a repair manual specific to your vehicle is absolutely crucial for success and to avoid damaging your engine. If you're not confident in your abilities, seek professional help. A incorrectly installed timing belt can result in severe and costly engine damage.
