Knock sensor removal

So in the process of doing a complete cooling system flush I removed the drivers side knock sensor with no problem other than a shower .Well the passenger side nut spins ( I used a 6 point socket so as to not round the bolt ) but the sensor itself won't budge .I reconnected the wires and flushed the system again but would like to remove and replace it so I can get a complete flush any suggestions on how to remove it without breaking it off in the block .Thanks for any help on this .

A pair of grove joint pliers or vice grips on the stub sticking out of the hole should do the trick

Before using the pliers, spray some Freeze Off on the base of the sensor. Use a judicious amount.

Thanks for the replies and Fred I took your advice from previous posts and picked up a can the last time I was at the parts store now is my chance to try this stuff ot .

Lol. Stop and think about that a second.

The sensor has multiple parts and you already said the hex portion is spinning while the base section does not move. No amount of penetrant is going to solve that issue. Penetrant will not make those parts stick together and come out.

Very common issue with knock sensors. Get the sensor out and grab a new one from Rock Auto for 25 bucks.

Woody I have to believe that Fred meant spraying this stuff on the threads to facilitate removing the sensor I know there is no way that this thing is going to go back together . I bought a replacement before I started this so I know the the nut portion is basically press fit onto the base portion . Stopped and picked up a 20 inch channel lock plier and another knock sensor it's a tite fit do to the starter in the way so with the pliers and the Freeze Off ,I think it will work out . I was thinking about heating it up but right now there is a lot of old oil/grease and the last thing I need to do is catch something on fire . One of my goals this winter is to spend some time underneath and completely clean the engine and tranny areas . 

Wojtek wrote:

Woody I have to believe that Fred meant spraying this stuff on the threads to facilitate removing the sensor I know there is no way that this thing is going to go back together . I bought a replacement before I started this so I know the the nut portion is basically press fit onto the base portion . Stopped and picked up a 20 inch channel lock plier and another knock sensor it's a tite fit do to  the starter in the way so with the pliers and the Freeze Off ,I think it will work out . I was thinking about heating it up but right now there is a lot of old oil/grease and the last thing I need to do is catch something on fire . One of my goals this winter is to spend some time underneath and completely clean the engine and tranny areas . 

Common sense would say you're correct.

Wojtek wrote:

Woody I have to believe that Fred meant spraying this stuff on the threads to facilitate removing the sensor. 

He did indeed. That’s what I get for replying to threads 7 hours after surgery. Sorry about that.

He did indeed. That’s what I get for replying to threads 7 hours after surgery. Sorry about that.[/quote]                             It's the thought that counts ! Hope all is well with you !