OK, was changing coolant in my 1993 (its been > 10 yrs).
Emptied the radiator.

Then went to yank a knock sensor. Made sure I had the correct socket and that it was seated correctly.

To my horror, the knock sensor insert just spun around in its shell....

So I have a question:
1. Did that destroy the knock sensor? (methinks no, bc its not like there is an internal wire getting twisted off inside it)
2. Should I just cut my losses changing the coolant, doing a partial replacement (of what came out the radiator)
3. Do I try to get vice grips on the outer shell and get it out...I will now have to likely buy a new one, and I worry if the new one's quality is the same as the old ones.
Maybe it is because I think that type of knock sensor was used on many engines (LSx and even non GM engines).
***I am not sure I can get vice grips on it, due to my Canton Road Race pan swingouts and headers.....This is on the drivers side FYI
4. Do I need to remove BOTH knock sensors to drain the coolant, or is just 1 good enough.


Any advice is appreciated!

 

I destroyed one on my 96 when I first got it.

I believe my local chevy dealer had one in stock and it wasnt a bad price.

I believe I either used vice grips or a big set of adjustable channel locks to get it out.

I would TRY to open both to get the coolant out.

 

https://www.corvetteforum.com/forums...ush-works.html

Diz, You are a smart guy. Please take my word on this. This method I describe is MUCH better than just pulling the Knocks. It actually agitates the water in the block area rather than just a drain. You will be Fricking amazed at the crap that comes out. Dan

 

I would replace both knock sensors at the same time. They are tuned to a specific range and are a fragile device. I saw that your Knock sensors are $25.00 for the Delco original type at Rockauto. At Zip their's are twice the price so I would attribute that to the "Corvette Tax" Makes me happy to have just one in my old L98. On my L98 the knock sensor was D-E-A-D and the timing was being held back due to that fact. New Knock sensor and it turned into a Corvette again. The web says it is a close to $300 job to change the Knock sensor for you at a shop. On my L98 the knock sensor was filthy and dirty so I matched the socket up on the clean on the new part and the removed the old sensor. After drying out the coolant I went ahead and installed a new knock sensor and fresh coolant. It was not any kind of horror story but then mine was the original and it was not cranked down too tight.

If you are worried about getting it off I would soak the sensor in a good penetrating oil like KROIL Oil and then heat it with a hot air gun and soak it a second time and wait a few minutes. That will get most parts freed up. If you use the right tool it will get the part off without damaging it. The trick to Knock sensors is they don't need to be cranked down and a lot of folks think it has to be cranked to ~50 Ft pounds. The truth is they need to be cranked down to 14 foot pounds and that is all. I would use a good pipe sealer on the threads to prevent any coolant issues.