Extracting a broken knock-sensor? Need advice.
Thread Starter
Instructor
Joined: Mar 2005
Posts: 178
Likes: 0
From: Thornton CO
Extracting a broken knock-sensor? Need advice.
Hello everyone at CF!
I need advice on the extraction of a broken knock-sensor. The sensor head broke off when I was trying to remove it so I could replace it with a new one. So, I have about a 1/4 inch or less of the sensor's bolt section just sticking out of the engine block now. Apparently the previous owner or service tech either over torqued the sensor or put on some/too much thread-lok (type) or other sealant type stuff on it. I see red on the visible threads, so I am assuming it could be RVT sealant.
Well, how should I approach to extraction of the remaining knock-sensor bolt part?
~Chris
I need advice on the extraction of a broken knock-sensor. The sensor head broke off when I was trying to remove it so I could replace it with a new one. So, I have about a 1/4 inch or less of the sensor's bolt section just sticking out of the engine block now. Apparently the previous owner or service tech either over torqued the sensor or put on some/too much thread-lok (type) or other sealant type stuff on it. I see red on the visible threads, so I am assuming it could be RVT sealant.
Well, how should I approach to extraction of the remaining knock-sensor bolt part?
~Chris
Thread Starter
Instructor
Joined: Mar 2005
Posts: 178
Likes: 0
From: Thornton CO
Well, no luck with the vise grips of the penitrating lub. It's in such an ackward spot...it's the one on the passenger's side with the transmission lines that go to the radiator.
Is there anything out there that can eat at RTV sealant?
I think I'm going to try the tap-n-easy out method. But since it is in such an awkward spot, I'll need to buy a extra long drill bit to get a hole in it at a proper angle.
I'll have to wait until Sunday to try it thought...too busy tomorrow.
Is there anything out there that can eat at RTV sealant?
I think I'm going to try the tap-n-easy out method. But since it is in such an awkward spot, I'll need to buy a extra long drill bit to get a hole in it at a proper angle.
I'll have to wait until Sunday to try it thought...too busy tomorrow.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
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
Thread Starter
Instructor
Joined: Mar 2005
Posts: 178
Likes: 0
From: Thornton CO
Well, it boiled down to getting my bother-in-law (a mechanic) to take on the problem and fix it.
He had some more specialty tool to work with...I'm glad I have him in my family!
First, he tried a specialty type of vise grip pliers, and that did not work.
The next day, he brought in his angled air-drill and professional extractor set. Well, he drilled a hole and tried to extract...the bit dug in and then spun. He then tried the next size up...same result. Three more times...same result.
Finally, (same night) he had his tap bit to rethread the hole...he drilled out mostly what was left of the sensor bolt and rethreaded it...basically the same threads just removing the sensor metal from the thread grooves.
So, all is well once again and I can finish my radiator replacement and a few other things!
Moral of the story...don't over torque the knock sensors and leave them untouch for years!
~Chris
He had some more specialty tool to work with...I'm glad I have him in my family!
First, he tried a specialty type of vise grip pliers, and that did not work.
The next day, he brought in his angled air-drill and professional extractor set. Well, he drilled a hole and tried to extract...the bit dug in and then spun. He then tried the next size up...same result. Three more times...same result.
Finally, (same night) he had his tap bit to rethread the hole...he drilled out mostly what was left of the sensor bolt and rethreaded it...basically the same threads just removing the sensor metal from the thread grooves.
So, all is well once again and I can finish my radiator replacement and a few other things!
Moral of the story...don't over torque the knock sensors and leave them untouch for years!
~Chris
Last edited by stearnman; Sep 20, 2007 at 12:31 PM.
Drifting
Joined: Dec 2005
Posts: 1,313
Likes: 2
From: High Ridge Missouri
