How to Replace a Thermostat on a 1997 BMW 528i

1. Take the thermostat housing cover off by removing the two mounting bolts that holds the cover onto the 528i intake manifold. The cover is located on the top of the engine directly to the right of the throttle body. It's connected to the radiator hose.
2. Pull the thermostat out of the intake manifold of the BMW by pulling up on it. The thermostat rests on a machined-lip inside of the manifold. It is not permanently attached to the engine so it can be pulled out. Once the thermostat has been removed, scrape the old gasket off of the manifold with a small scraper. Do not get any gasket material into the hole. This can cause blockage in the coolant system. Press a shop towel into the hole and remove it once the gasket has been removed.
3. Set a new gasket into place and put a new thermostat into the intake manifold. Once in place, bolt the thermostat housing cover back into place using the original bolts that were previously removed.