Intake manifold Bolt damaged thread?

Tiny
JOE1953
  • MEMBER
  • 1998 CHEVROLET CAPRICE
  • 3.8L
  • V6
  • 2WD
  • AUTOMATIC
  • 1,632,268 MILES
Where the carburetor bolts to the intake manifold one of the thread holes is damaged inside the intake manifold. How do I fix it or can I just use the three bolts to hold the carburetor to the manifold?
Monday, February 10th, 2025 AT 1:01 AM

2 Replies

Tiny
STEVE W.
  • MECHANIC
  • 13,984 POSTS
The easiest solution is to Heli-coil the hole if it isn't severely damaged. You would get the proper sized kit that includes the drill bit, the special tap and the insert and install tool. The process is simple. The hole is drilled with the bit, then you tap the threads and install the insert. The tang on the insert gets snapped off and now you have new threads in the original size to use. You want all four bolts, then can warp and leak at the base even with all four so trying to use only three is just asking for trouble. Many parts stores have the master kits as loaner tools. You "buy" the kit and install the inserts and when you return the kit in good shape, they give you back the money. You end up paying only for the inserts you actually use instead of having the rest of the kit to store.

This is a video showing the full process in a new hole, in your case you would use the damaged hole and just drill it out.

https://www.youtube.com/watch?v=xigq7aPpff0
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Monday, February 10th, 2025 AT 11:10 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,154 POSTS
This car has a carburetor? Can you upload an image?
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Monday, February 10th, 2025 AT 11:11 AM

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