Hi!

I have read a lot of tips and procedure....I applied any of them, but the hex bolt won't turn , not even slightly.

I strongly believe the body of the sensor is seized as well.

Tried PB blaster, WD40, a large amount of other products, I put an allen key and hammered the bolt slightly, less slightly, I tried to apply heat with a plumber solder( an electronic joint solder look-a-like , but larger), used a small impact wrench , then a bigger one, then re-tried with every tool used before adding a lot of curses, to no avail. More: the hex bolt is not stripped, has not a single mark of my effort to unbolt it,like it is made of a special unbreakable material from an alien spacecraft .

Can you suggest me another worthwhile shock therapy .

Thank you.

 

Liquid nitrogen.

 

really?
Francesco

 

Run the engine to get everything nice and hot. The CPS bolt is held in with blue thread locker so getting it warm is important.

 

That is usefull, didn't know about blue stuff on bolt thread. Thank you...

 

The release temp for blue Loctite is about 350 degrees F. getting the "engine hot" is not sufficient.

 

get a 5mm allen key in a socket, and use an impact screwdriver if needed. Though I have always been able to extract with a regular socket, extension and ratchet without issue. It can take a fair bit of torque.
Alternatively get an external bolt/stud extractor that grips the outside of the bolt and remove with that.

 

If it's not stripped, your lever arm is too short. If it strips or breaks, drill it off. PITA to do, but sometimes the only solution.

 

Used impact screw driver and socket, socket and a 15 " lever.nothing, it seems it turno some degrees, but it is just flexing.
AO, i think you are one of the voices of wisdom here....but drilling bits in that area of the engine bay, make new thread, and still not knowing if the sensor is seized as the bolt... Sounds a bit scary.. I hope to solve problem without that estreme solution. That CPS works, so i can leave it in place for the moment.

 

Francesco,
Heat Heat Heat (with a MAP torch)
Quench with a 50/50 mix of Acetone and ATF or your favorite penetrating oil(s), do not inhale while doing this.
Smack with a ball peen and a punch...
Repeat until bored and then soak for a few days in a 50/50 mix of Acetone and ATF or your favorite penetrating oil(s).
Try an impact driver as Lizard (Colin) suggested. (Do not use a 2 kg. sledge hammer on it though, no matter how tempting).
Repeat as necessary until it releases or breaks.
The idea is to break the corrosion with repeated heat cycles and rapping with the hammer. Ideally, you heat the surrounding metal, and don't heat the bolt directly.
The Liquid Nitrogen option works too, but you have to try to keep it on the bolt itself...the idea is to shock/contract the bolt enough to break the corrosion free.

 

Not sure if I was lucky or not but I soaked it in PB Blaster and walked away for a whole day. I CAREFULLY broke it loose the next day and then pulled the sensor out by the cord, jiggling and yanking on it.

 

She was just messin' with you...

 

Boys, sensor is out!
Acetone and ATF, 3-4 times , then I hammered the bolt with a plastic hammer.then it with no much effort.
The sensor at that point came out about1 inch, than was again blocked. some acetone/ATF mix and the sensor now is out...

acetone /aTF is the most penetrating lube ^ have ever tried.it melted also the blue thread locker.

Thank you guys!

After this effort , I hope the new sensor will better the engine behaviour....

Francesco from North Italy