* Driver's side door jamb: Check the sticker on the driver's side door jamb. While it won't directly say "engine code," it *will* list the engine displacement (e.g., 4.5L, 4.9L, 5.0L, 5.7L, or 7.4L). This narrows down the possibilities significantly. Knowing the displacement helps you look up the corresponding engine code.
* Vehicle Identification Number (VIN) plate: Located on the dashboard, usually visible through the windshield. The VIN itself doesn't contain the engine code directly, but you can use the VIN to get a full vehicle history report from a service like Carfax or AutoCheck. These reports often list the engine details.
* Engine block itself: The engine code might be cast directly onto a part of the engine block. This is the most challenging method because you'll need to visually inspect the engine, potentially needing to clean some areas to see it clearly. The location varies depending on the specific engine.
* Owner's manual (if you have it): The original owner's manual *might* have the engine specifications, though not always the specific code itself.
Once you've identified the engine displacement:
Use online resources (like Cadillac forums, parts websites, or repair manuals) to match the displacement with the engine code. For example, a 4.5L might be a specific HT4100 code, while a 5.7L might be a LT1. Searching for "[year] Cadillac Fleetwood [engine displacement] engine code" should yield helpful results.
Remember that the engine code is different from the engine displacement. The displacement tells you the engine's size, while the code is a unique alphanumeric identifier specific to that engine's design and specifications.
