Screw Broken in engine
Thread Starter
Intermediate
Joined: Apr 2009
Posts: 41
Likes: 0
Screw Broken in engine
Hi I have a 1991 vette L98 engine. I was going to change the thermosat to a 180 deg. I took out one screw and it came out fine. I tryed taking out the other screw and it broke?
Anyone have any ideas how to get this broken screw out??
thank you
Anyone have any ideas how to get this broken screw out??
thank you
Corvette Enthusiast
Joined: Oct 2007
Posts: 6,790
Likes: 2,697
From: So. Cal.
2025 C7 of the Year Finalist- Unmodified
2024 C7 of the Year Finalist - Unmodified
2023 C7 of the Year Finalist - Unmodified
Vette
Very carefully drill a hole on the center of the bolt and us an easy out. Always use anti-seize on threads when you put it back together. I always use anti-seize when threading into aluminum.
Corvette Mike
Corvette Mike
Pro
Joined: Jun 2008
Posts: 610
Likes: 1
I'll second that, and stress that you must hit dead center with the hole. You only get one shot at it. If there is anything sticking out, filing it flat will help.
Common screw extractors...
Common screw extractors...
Last edited by M. Schumacher; May 9, 2009 at 09:52 PM.
Pro
Joined: Dec 2008
Posts: 512
Likes: 2
From: Denton TX
I hate to be discouraging, but it sounds as if you have never done anything like this before. Not knowing what an easy out was was the first clue. I would suggest that your next step is to have the car towed to a mechanic who is competent.
You may want to brace yourself for some significant cost. If the manifold has to be pulled or in the event the bolt cannot be removed, a new manifold.
When working with aluminum, there isn't much room for error. Always...and I stress always use studs in aluminum if you can...secondly, when working in the water jacket..the studs should be stainless steel...and always use anti-sieze regardless of the situation. Spark plugs in particular should be installed with anti-sieze.
Best of luck...the learning curve is steep and expensive
Sam
You may want to brace yourself for some significant cost. If the manifold has to be pulled or in the event the bolt cannot be removed, a new manifold.
When working with aluminum, there isn't much room for error. Always...and I stress always use studs in aluminum if you can...secondly, when working in the water jacket..the studs should be stainless steel...and always use anti-sieze regardless of the situation. Spark plugs in particular should be installed with anti-sieze.
Best of luck...the learning curve is steep and expensive
Sam
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
Pro
Joined: Jan 2009
Posts: 686
Likes: 4
From: Austin Texas
Instructor
Joined: Oct 2008
Posts: 163
Likes: 0
From: Gulf State
I had a about the same issue and made my repair today. I had a bolt hole clean up bit break off in one of my tstat bolt holes. I removed the air plenum so I cold access the area more easily. I started drilling as close as I could get to center of the broken piece with a very small drill. Then I increased bit sizes until I drilled out all of the broken bit except for the threads. The I used a awl and hammer and knocked the threaded piece into the center of the hole. Then I use the largest drill and drilled thru that debri. Every time I drilled I use a magnet to clean up the drill debri to keep the hole cleaned out. It took about an hour but it worked out fine for me. When I got all the pieces out I used a tap and cleaned up the threads for the bolt hole. I am not a great mechanic but I took my time and used my head and it worked our well for me. Hang in there and lose your cool.