Thermostat bolt removal issue?

2003 CHEVROLET MONTE CARLO
118,000 MILES • 2WD • AUTOMATIC
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DANIEL NELSON2
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I need help getting off the bolts that hold the thermostat the bottom one in particular.
Nov 12, 2023 at 11:24 AM
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JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
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Hi,

I need to know which engine you have. Is it a 3.4L or a 3.8L? (see pic below).

Let me know. If it is the 3.4, you will need to remove the crossover pipe.

Take care and I'll watch for your reply.

Joe

See pic below.
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Nov 12, 2023 at 8:52 PM
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DANIEL NELSON2
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  • 44 POSTS
It is the 3.4.
Nov 14, 2023 at 9:19 AM
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DANIEL NELSON2
  • MEMBER
  • 44 POSTS
How do I take off the crossover pipe?
Nov 14, 2023 at 9:20 AM
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JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 110,190 POSTS
Hi,

Yep, you have to remove the exhaust cross-over pipe to access the thermostat. I attached the directions below.

The first four pics are for thermostat replacement. In pic 2, I highlighted what needs to be removed. The cross-over pipe directions start with pic 5.

Let me know if this helps.

Take care,

Joe

See pics below.
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Nov 14, 2023 at 2:52 PM
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DANIEL NELSON2
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  • 44 POSTS
What size are the bolts because I lost one?
Nov 14, 2023 at 4:23 PM
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JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
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Hi,

That type of information isn't provided in my manual. Is it possible to remove one of the other two and have it sized for replacement?

Let me know.

Joe
Nov 14, 2023 at 4:30 PM