I've spent DAYS taking off the head to replace the head gasket and it's been one headache over another. This is the LAST thing I need to unhook before the head comes off but it won't come off.

It seems like it would unscrew but I'm not sure as it isn't budging. I've tried a 12mm wrench and it seemed to be a little big and kind of stripped it. I also tried pliers and other things but no go. I also put some PB Blaster on it.

What is it and how do I get it off? Thanks!

 

Water temp sensor.
Put a six sided deep sock over it and it WILL come out. It's just brass and wont ever sieze in aluminum at least I have never seen one sieze, ever.

PS the wire pulls right off, just a bit snug but pulls off the same.

 

Deep socket and breaker bar should do the trick.

 

So I can pull the wire off of the nut?

 

Yes.

 

Yeah the six sided deep socket works perfect, throw a small breaker bar on the end and be firm but gentle. should loosen right up.

 

THANK GOD. Thanks everyone.

 

a DEEP socket and possibly in 1/2 drive or just use an adapter, 1/2F to 3/8M.


wait you didn't know that wire just slipped off ?

 

^^bummer lol, Well atleast he didn't have the thought to just start yanking on wires.

 

It's one of two wires (that I can think of) that do. Can't blame the guy for wanting to avoid breaking any connectors.

 

No I get that, i'm not saying he's dumb, just something's are common sense "no clip, just slip". plug wires and any spade terminal things starter plug etc.

 

Well everything up until that point was all bolts, nuts, or hose clamps. There wasn't anything indicating it was supposed to be pulled off and I didn't want to yank on wires of an old car and have a bigger problem (and it looked a lot like the 02 sensor).

It took 2 seconds to get off once I pulled the wires out

 

Lol... O2 sensor...

 

Have you never seen a 1 wire O2 sensor? It kind of does.