How to Change a Thermostat on a 1999 Oldsmobile

by Lisa Wampler
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If you need to change the thermostat in your 1999 Oldsmobile, you will need basic hand tools, a few dollars for replacement thermostat and RTV gasket maker to complete the job. If you've noticed that your engine had been running hot, this could be all it will take to keep your aging Oldsmobile on the road for years to come. When the thermostat stops working, the engine overheats, and when this happens on an engine that has high miles, it can cause several issues that could cause the need to overhaul the engine.

Step 1

Remove the radiator hose from the thermostat housing by prying the old retaining clip off of the hose with a screwdriver. Pull the hose off of the thermostat housing.

Step 2

Remove the bolts that hold the thermostat housing onto the intake manifold of the Oldsmobile with an adjustable wrench. With the bolts removed, lift up on the thermostat housing to remove it from the manifold.

Step 3

Pull the old thermostat out of the intake manifold and plug the hole with a cotton towel.

Step 4

Scrape the old gasket off of the intake manifold with a razor or a scraper. Do not get any of the old gasket into the intake manifold.

Step 5

Remove the cotton towel from the hole in the intake manifold and place the new thermostat into place. The thermostat will be marked to indicate which end should be placed into the intake manifold.

Step 6

Place a bead of silicone RTV gasket maker onto the bottom edge of the thermostat housing and then bolt the housing back onto the intake manifold of the Oldsmobile.

Step 7

Place a band clamp onto the radiator hose and secure the radiator hose back onto the thermostat housing.

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