Coolant Temperature Sender Broken

Scirocco84 · Apr 28, 2011

Hello,

First:
1994 XJ Sport
4.0L HO
5 speed manual

Second:
While trying to replace my coolant temperature sender on the back of the head, I broke the plastic connector off, stripped the brass nut, and finally tore off the stripped brass nut, leaving the hollowed out threads in the head. Frustrating, but my own fault. I'd like to tap out the hole so I can replace the sender, but I'm not sure what the tap size is and I'll have to go buy the right tap. So...

1. Do you guys know what size the threads are on the coolant temperature sender? I assume that their NPT.

2. Do you guys have any experience with breaking off the sender? Is there an acceptable chewing gum and bailing wire fix or a mod that I can do that might be easier than getting a tap in between the firewall and the head?

Thanks guys.

Wayne Sihler · Apr 28, 2011

Do you have the coolant drained out of the block ? If you dont and no water is comming out then,part of the sensor is still in the head.

You may be able to drive in an EZ-OUT and IF it catches the brass part still in the head it may back it out.
Only other method I know is to drill & tap.

b5blue · Apr 29, 2011

Try asking a parts store or hardware store for "E-Z (easy) Outs". Look at the different sizes to see if one fits the hole your left with. You'll see what I mean when ya see one.

8Mud · Apr 29, 2011

In situations like that I've had pretty good luck drilling through the center, gradually increasing the size of the drill until I just skin the threads. Then pry whatever is left of the threads to the center with a very small screw driver or awl and remove with a pair of needle nosed pliers.
I use a battery drill with a slip clutch, less chance of breaking the drill bit. I also bought an angle drill (elbow) attachment for places like that.
An easy out may work, but to tell you the truth, I've had them rarely work. Whatever you do don't break off an easy out or drill bit in there, things can go from bad to worse quick.

MD83ZXJ · Apr 29, 2011

+2 on the broken easy-outs....I bought a set of reverse turn drill bits that can help draw out the metal...I will never risk the brittle hardened steel easy-out that snaps off and then is tough to get out.

cruiser54 · Apr 29, 2011

MD83ZXJ said:
+2 on the broken easy-outs....I bought a set of reverse turn drill bits that can help draw out the metal...I will never risk the brittle hardened steel easy-out that snaps off and then is tough to get out.

My preferred method also.

ehall · Apr 30, 2011

It's a 1/8 NPT thread. It's a tapered plumbing thread that allows it to be self-sealing. Honestly I would drill it until you have most of the crap out of the threads, then use a 1/8 NPT tap to chase the threads, then rinse the hell out of the block to get out the little metal bits so that you don't destroy the water pump blades. You can buy the tap at any home improvement store and most small hardware stores.

CharlesS · Apr 30, 2011

I have the tap you need and if you need assistance I live in Escondido (I-15 & Hwy 78); contact me at [email protected]

Charles

Scirocco84 said:
Hello,

First:
1994 XJ Sport
4.0L HO
5 speed manual

Second:
While trying to replace my coolant temperature sender on the back of the head, I broke the plastic connector off, stripped the brass nut, and finally tore off the stripped brass nut, leaving the hollowed out threads in the head. Frustrating, but my own fault. I'd like to tap out the hole so I can replace the sender, but I'm not sure what the tap size is and I'll have to go buy the right tap. So...

1. Do you guys know what size the threads are on the coolant temperature sender? I assume that their NPT.

2. Do you guys have any experience with breaking off the sender? Is there an acceptable chewing gum and bailing wire fix or a mod that I can do that might be easier than getting a tap in between the firewall and the head?

Thanks guys.

Coolant Temperature Sender Broken

Scirocco84

NAXJA Forum User

Wayne Sihler

NAXJA Member

b5blue

NAXJA Forum User

8Mud

NAXJA Forum User

MD83ZXJ

NAXJA Forum User

cruiser54

NAXJA Forum User

ehall

NAXJA Member

CharlesS

NAXJA Forum User

Similar threads