How can I fix stripped threads in the Engine Block?

white69mach1 · **Joined:** Wed Feb 24, 2010 11:15 pm **Posts:** 29

I am doing my Timing belt and when I attempted to install the exhaust idler pulley, I found that the tip of the threads in the engine block are stripped. The first 1/8 or so are stripped, what are some of my options to fix this?

ATXKJ · **Posted:** Thu Dec 01, 2011 9:59 pm

Helicoil - need the correct thread
- but they have kits with the drill bit

actually - you said 1/8 - you might be able to clean that up with a tap - or even a screw that has the threads ground down slightly

BlackLibertyCRD · **Posted:** Fri Dec 02, 2011 12:57 am

They have such thing as a thread chaser that don't undercut like a tap.

CIMARRON13 · **Posted:** Fri Dec 02, 2011 5:06 am

I have a retread kit that I have used to clean up bolts and nuts. I bought it as sears for around $50 years ago. Came with all the different sizes that I have ever needed. A friend used it once on his engine block after cross threading a bolt. Worked great.

WolverineFW · **Posted:** Fri Dec 02, 2011 11:11 pm

BlackLibertyCRD wrote:

They have such thing as a thread chaser that don't undercut like a tap.

Try this first....save you a big headache if you can clean it up enough.

white69mach1 · **Joined:** Wed Feb 24, 2010 11:15 pm **Posts:** 29

The thread is a reverse thread. I am guessing that a regular thread chaser isn't going to work. Am I correct in this thinking?

Joe Romas · **Posted:** Sat Dec 03, 2011 9:20 am

white69mach1 wrote:

The thread is a reverse thread. I am guessing that a regular thread chaser isn't going to work. Am I correct in this thinking?

Your totally correct if it's a left hand thread.

papaindigo · **Posted:** Sat Dec 03, 2011 10:37 am

Check around for a left hand tap in the appropriate size. They are not that hard to find even Sears has them. Alternatively if you can find a reverse thread bolt of the proper size it's apparently, I'll let others that have done this weigh in, possible to grind/file the tip to make a thread chaser.

white69mach1 · **Joined:** Wed Feb 24, 2010 11:15 pm **Posts:** 29

papaindigo wrote:

Check around for a left hand tap in the appropriate size. They are not that hard to find even Sears has them. Alternatively if you can find a reverse thread bolt of the proper size it's apparently, I'll let others that have done this weigh in, possible to grind/file the tip to make a thread chaser.

Thanks for the help, I was able to make a thread chaser out of a the old bolt for the idler pulley using a dremel. Now its time to put everything back together.

papaindigo · **Posted:** Sat Dec 03, 2011 5:24 pm

Be careful putting the tensioiner back on as both geordi and lgoodbar found there was what's apparently a factory installed helicoil where the tensioner threads in. That helicoil will pull out if you try to install the tensioner last.

How can I fix stripped threads in the Engine Block?

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