What size thread and size are the thermostat housing bolt?

2004 OLDSMOBILE SILHOUETTE
153,000 MILES • 3.4L • 6 CYL • 2WD • AUTOMATIC
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RENEE ROGERS
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Bolts stripped need to know replacement size.
Feb 7, 2021 at 8:18 AM
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ASEMASTER6371
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Good morning,

The bolts are 8 mm 1.25 pitch about 1 1/4 inches long.

https://www.2carpros.com/articles/replace-thermostat

https://www.2carpros.com/articles/coolant-flush-and-refill-all-cars

Roy

Thermostat Replacement

Removal Procedure


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1. Remove the air cleaner and duct assembly.
2. Drain the coolant until the coolant level is below the thermostat.
3. Remove the crossover exhaust pipe.
4. Remove the radiator hose from the thermostat housing.
5. Remove the thermostat housing bolts and clean any sealer from the bolt threads.
6. Remove the thermostat housing and gasket.


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7. Remove the thermostat.
8. Clean the mating surfaces.
Feb 7, 2021 at 8:26 AM