Temp sensor stuck in head

[josh_t]

is it typically a big deal to remove the temperature sensor on an A14? this one wont budge. i have used a 6 point socket and it started stripping the head and i took a chisel and hammered on it. now the head of the sensor is unuseable. but isnt the metal soft enough that i can somehow collapse the whole thing and remove it?

[80datson]

Try pb blaster and vise grips

[ggzilla]

This is not common -- but it happens sometimes. There are two parts, the hex part and the sensor part. Use a pipe wrench to remove the hex, then twist the sensor while working it out.

 

It only sticks if the aluminum-to-brass interface has corroded a bit. The same thing can occur with other Datsun engines.

[josh_t]

the new part is one piece. idk why but it is. and how the hell am i supposed to get a pipe wrench in there? i'll have to remove the alternator and bracket and the valve cover just to get any kind of room in there.

[ggzilla]

Yep, do what is necessary. Or spend even more time messing around...no need to remove the valve cover. The temp sensor is just in front of the #1 spark plug.

 

[josh_t]

Yep, do what is necessary. Or spend even more time messing around...no need to remove the valve cover. The temp sensor is just in front of the #1 spark plug.

 

 

 

i know where its at but the valve cover kinda hangs over a litte. so it might prevent me from getting to the sensor easily. all i have is like a 14" pipe wrench.

[banzai510(hainz)]

try heating it with a torch.

 

I have cracked mine out on L motor and had to buy new housings.

[josh_t]

still the same problem except its been 3 more months. i decided to take the easy out i had in it as a plug and try to remove it this time. used PB blaster. A LOT of PB blaster and on many occasions. used quite a few different tools, still stuck but now i'm to the point where i got rid of half the brass part and the inside of the steel part is exposed. i bored it out a little bit with a drill bit. the biggest one i have. i was going to drill it out and helicoil it if i went too far or save the threads if i could just collapse the steel and remove it that way. i have the head off out of curiosity, since a head gasket is less than 10 bucks, and it took less than 30 minutes to remove everything off the top of the motor in one piece, i'm not losing anything. I found out that i still have hone marks and my pistons have such a thin layer of carbon that i can see letters stamped in a couple of pistons. There is a "C" in piston 2 for example. They are dished and the raised portion on them is mostly clean and only the dish is dirty. No ridges. Clean chambers too. I'm assuming there was a rebuild not too far back done on it. It also spins extremely easy. I can turn the crank with just my fingertips on the crank pulley. And there is is very little side to side play in the pistons, I'm assuming that becomes almost 0 from the aluminum expanding when its warmed up. This stupid sensor is my only problem on the whole car, mechanically and electrically.

[ggzilla]

Use heat to remove it.

 

Heat it up!

 

Normally, both part are made out of brass, both the threaded nut and the sender itself:

[Kisor]

I wouldn't drill too much on it. If you look at that pic above the sensor uses a tapered seal at the bottom. The taper is machined into the head.

 

You mentioned your new sensor is one piece so its fine to kill the brass collar but the only way that it will seal in the head is by that tapered seal.

 

I'm gathering you are or will take the head off? If all else fails take it to a machine shop. Just explain to them how its made and not to mess up the taper in there if it comes to drilling.

[josh_t]

If i could get the steel sleeve/bolt out, then i probably wouldnt be having this problem. And the head is off now. It seems like it will be easier with it out of the car.

[ggzilla]

Make sure your replacement sensor is all brass. Just say no to cheap steel sensors the corrode against the brass and aluminum.

[Ranman72]

Make sure your replacement sensor is all brass. Just say no to cheap steel sensors the corrode against the brass and aluminum.

 

I have been able to remove them by chiseling inward with small flat screw driver to break it in two then you can usualy just carfuly peel it away with the screw driver

[HRH]

You have any pics of this problem? I can't see how you haven't been able to get this out in three months. Blue wrench or pipe wrench should have done it. Unless the previous owner set it in with JB weld.

[josh_t]

sorry for the bump but i havent been on in a while and i know how i hate it when ppl never reply. it has a new (used) head on it now so i have a working sensor, and i'm not in dire need of getting the old one out. i'll probably take it to a machine shop to have them fix a couple little problems the head has besides the sensor. this is my spare head for working on now.

[screamer510]

On my loose L20 housing:

 

Had the same problem. Ended up wrenching off the hex head, leaving a metal tab and wire sticking out of the housing. Drilled it out and got it to turn, but the threaded part had its own ideas. Then I got the threaded part out, and the brass tube was still stuck, but turning. Tried to tap it into the housing, tried to pull it out while turning, nothing I could do would work. I ended up drilling it out at a slight angle to thin the metal, pushing it back into the housing, chiseling it, trying to fold it in on itself. No luck. I finally got a big ass tap into the brass tube and was able to work it out that way.

 

A major PITA. I can't imagine doing it while the head is on! Whatever you do, BE CAREFUL! Good luck.

 

Dan