Knock Sensor Removal
Thread Starter
Racer
Joined: Oct 2008
Posts: 379
Likes: 30
From: Indian Mills NJ
Knock Sensor Removal
There have many threads on how to change the anti-freeze and this is what I was trying to do. Drained the radiator and then went after the knock sensors. After some resistance it seemed that the sensor was turning, but that is all it did turn. It didn't seem to be coming out of the socket in the block.
It is a deep threaded sensor and it takes a long time to get out or has something broken inside of it.
The center part of sensor turns but the metal ring around it does not.
Any help would be appreicated.
It is a deep threaded sensor and it takes a long time to get out or has something broken inside of it.
The center part of sensor turns but the metal ring around it does not.
Any help would be appreicated.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 414
From: WV
The whole sensor is suppose to turn, sounds like its broke.. Get a pair of channel locks or vice grips and grab the metel part and turn it out of the block..Make sure when you put the new one in that you tighten to the proper torque setting...WW
Thread Starter
Racer
Joined: Oct 2008
Posts: 379
Likes: 30
From: Indian Mills NJ
Knock sensor
That's exactly what I did before your response. Thanks for taking the time. When I did that the unit broke away from the part that screws into the block. Now I have this stud sticking out of the block. No anti-freeze has leaked out yet.
Any suggestions on this situation? I don't want to break this stud and create more problems.
Thanks again for your time
Any suggestions on this situation? I don't want to break this stud and create more problems.
Thanks again for your time
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
The threaded stud you have left in the block is part of the now broken sensor.
Sensor should look like this
http://cgi.ebay.com/ebaymotors/GM-KN...item256193a493
Thread Starter
Racer
Joined: Oct 2008
Posts: 379
Likes: 30
From: Indian Mills NJ
Knock Sensor Removal
Thanks again for all the help. Yes now I have a stud sticking out of the block. The one good thing is that I have a lift for the Corvette in the garage and I can get at the stud.
Looking for some advice or tips/short cuts to remove the stud.
Have ordered a new sensor.
Thanks again for the help.
Looking for some advice or tips/short cuts to remove the stud.
Have ordered a new sensor.
Thanks again for the help.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 414
From: WV
If theres enough of the stud sticking out use channel locks to grab it and turn it out , if theres not enough sticking out maybe you can drill it and use an easy out to back it out. Another option is maybe take a dremmel tool with a small cutting wheel and cut a grove in the center of the stud, then use a large screw driver to take it out .As an absolute last resort if theres room you could have a smaller bolt welded to the stud and back it out that way...WW
Last edited by WW7; Oct 1, 2011 at 09:21 AM.
Thread Starter
Racer
Joined: Oct 2008
Posts: 379
Likes: 30
From: Indian Mills NJ
Knock Sensor Removal
WW7- Appreciate your suggestions. This adventure will start up again on Monday. Have the replacement on order and should be here soon.
These knock sensors have never been removed. The 95 Corvette has 26,000 miles on it and it is a good possibility that the stud is frozen to the block. At least it is on a lift.
Thanks again and I will let you know how I make out.
These knock sensors have never been removed. The 95 Corvette has 26,000 miles on it and it is a good possibility that the stud is frozen to the block. At least it is on a lift.
Thanks again and I will let you know how I make out.
Pro
Joined: Jul 2006
Posts: 635
Likes: 1
I think you have some sealant around the threads, this could be old and hard and making it hard to turn out. Since it's broke already nothings keeping you from heating it slightly. I'd try to keep the heat on the stud as much as possible though and it doesn't need to be very hot either.
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Thread Starter
Racer
Joined: Oct 2008
Posts: 379
Likes: 30
From: Indian Mills NJ
Knock Sensor Removal
Received my replacement knock sensor today from Corvette Central.
In the photo on E-Bay that I used to purchase the sensor it shows a red sealant on the threads. My new one does not have the sealant. I have read that you should not put pipe tape or any other kind of sealant because it causes problems.
This coolant change has become a major pain.
Any help again about this sealant. I can see it on the stud sticking out of the block.
In the photo on E-Bay that I used to purchase the sensor it shows a red sealant on the threads. My new one does not have the sealant. I have read that you should not put pipe tape or any other kind of sealant because it causes problems.
This coolant change has become a major pain.
Any help again about this sealant. I can see it on the stud sticking out of the block.
Thread Starter
Racer
Joined: Oct 2008
Posts: 379
Likes: 30
From: Indian Mills NJ
Knock Sensor Removal
The saga continues. Contacted Corvette Central about the Knock Sensor they sent me without the red sealant. Advised them their photo in theirsale item shows red sealant on the screw threads, but when I received it from them the threads were bare of sealant. This is an important part of the sensor for sealing purposes.
Corvette Central admitted to me that they had made a mistake with that photo and that all replacement knock sensors do not have the sealant on the threads. They said they were sorry for the problem and would send me a tube a appropriate sealant, without charge. This all happened in one day and I got just a shipping notice that the sealant was on the way.
Thank you Corvette Central for making good.
Corvette Central admitted to me that they had made a mistake with that photo and that all replacement knock sensors do not have the sealant on the threads. They said they were sorry for the problem and would send me a tube a appropriate sealant, without charge. This all happened in one day and I got just a shipping notice that the sealant was on the way.
Thank you Corvette Central for making good.
Thread Starter
Racer
Joined: Oct 2008
Posts: 379
Likes: 30
From: Indian Mills NJ
Knock Sensor Removal
Hopefully this is the last of this saga.
My associate brought over to the garage a star type socket and was able to force it on the stud. A little pressure was used to do this attaching.
Then the two of us, my associate being 6-3 and 250 lbs put all our weight on a heavy duty bar and after some pulling and a few choice words were able to break the stud loose.
I had order a replacement from Corvette Central but the one they sent me did not have the sealant as advertised by them on e-bay. They good enough to send me some sealant, free of charge.
We flushed the system twice and burphed it a couple of times.
Took it out for a run yesterday and no codes just a nice ride.
Thanks to all for all their help and suggestions. Of course thanks to Corvette Central for making good on their product.
My associate brought over to the garage a star type socket and was able to force it on the stud. A little pressure was used to do this attaching.
Then the two of us, my associate being 6-3 and 250 lbs put all our weight on a heavy duty bar and after some pulling and a few choice words were able to break the stud loose.
I had order a replacement from Corvette Central but the one they sent me did not have the sealant as advertised by them on e-bay. They good enough to send me some sealant, free of charge.
We flushed the system twice and burphed it a couple of times.
Took it out for a run yesterday and no codes just a nice ride.
Thanks to all for all their help and suggestions. Of course thanks to Corvette Central for making good on their product.
Melting Slicks
Joined: Jan 2009
Posts: 3,181
Likes: 286
From: Puyallup Washington
Only twice
I just changed the coolant in my 1992 with 51000 miles. I had no problem getting the knock sensors out but I flushed it 6 times before I thought the water coming out was clean enough. Drain, fill, run to 200*, cool, drain, fill, etc. With cool down times it took 2 days.
Team Owner
Joined: Sep 2003
Posts: 20,179
Likes: 673
From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
The saga continues. Contacted Corvette Central about the Knock Sensor they sent me without the red sealant. Advised them their photo in theirsale item shows red sealant on the screw threads, but when I received it from them the threads were bare of sealant. This is an important part of the sensor for sealing purposes.
And save us all the expense of increased prices?
Well then again, you did prove your point.
Last edited by JrRifleCoach; Oct 8, 2011 at 01:20 PM.
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Glad it worked out. The knock sensor can be purchased from any dealer or local parts store. I just use teflon tape or pipe thread sealer on mine. When I was using the knock sensor, I would wrap a few turns of teflon tape and tighten lightly if I wanted to desensitize the signal from the sensors.
