Coolant Temp Sending Unit

[TimmyTXJ]

Does anyone out there have experience extracting broken sending units? I broke the top of the coolant temp sending unit clean off while attempting to replace it. It's broken completely flush to the block. Access is extremely limited as the sending unit is next to the valve cover on the driver side right next to the firewall. I can't get my drill anywhere near it so I can't use my EZ outs.

Any thoughts or tips?

[4.3LXJ]

That is a tight spot. No great ideas

[prcjeep]

ohhh... Sucks when that happens... When i broke mine off flush i was able to get it out due to the nut still being ever so taller. It's just so dang small and in such a tight place that it will be very frustrating

[Mudderoy]

Does anyone out there have experience extracting broken sending units? I broke the top of the coolant temp sending unit clean off while attempting to replace it. It's broken completely flush to the block. Access is extremely limited as the sending unit is next to the valve cover on the driver side right next to the firewall. I can't get my drill anywhere near it so I can't use my EZ outs.

Any thoughts or tips?


When removing this sensor, and I haven't done it before, I'll heat it up with a torch and "wax it" using paraffin - the wax will usually wick in between the threads, and help release it. Also, the process of heating copper and copper alloys and allowing them to gradually cool will make them incrementally stronger - which also helps. Don't heat past 500-550*, if you can help it (this is why I keep a selection of Tempil sticks on hand. Check your local welding supplier.)

When installing a new sensor, I'll liberally coat the threads with never-seez.

:link: (http://www.cherokeeforum.com/f2/temp-sender-broke-off-flush-head-46885/)

[reddragon72]

this is where a welder comes in handy. You could simply tack weld a small bolt or screw onto it and back it out. Done this for a couple broken bolts where I torqued them to much lol

You could also use a small drill bit or dremel sideways(kinda laying horizontally) to make a small cut in the middle of it for a flat head screwdriver.

[TimmyTXJ]

ohhh... Sucks when that happens... When i broke mine off flush i was able to get it out due to the nut still being ever so taller. It's just so dang small and in such a tight place that it will be very frustrating

Yeah tell me about it! As it stands, the bottom half of the plug is intact so at least I don't have coolant spraying out from the block. I'm thinking of trying one of those flexible drill extensions. I can just barely get an EZ out on there by hand but I just can't seem to get any purchase on the brass plug. What a PITA!

[TimmyTXJ]

this is where a welder comes in handy. You could simply tack weld a small bolt or screw onto it and back it out. Done this for a couple broken bolts where I torqued them to much lol

You could also use a small drill bit or dremel sideways(kinda laying horizontally) to make a small cut in the middle of it for a flat head screwdriver.

Thanks for the ideas Scott. Unfortunately, a welder is on my list of "would really come in handy" tools instead of "tools I have at hand" I'll take a look and see if I can get the dremel down there... it's a really tight spot. What part of Cypress (assuming TX) are you in? That's my neck of the woods too!

[BlueXJ]

I have only had this problem once and I removed the manifold to get to that one. I know this is not the only way but it is what I chose to do. I made it into an oppurtunity to replace the gaskets and to remove and clean my throttle body.

[TimmyTXJ]

Okay so apparently it's been nearly a year since I broke the stupid temp sensor. My apologies to anyone that's been waiting to hear progress.

I finally went back at it a few months ago. I disassembled the top half of the engine and stood on a stool to get better access. I was able to get a drill solidly on the brass and drill out a starter hole for and EZ out. I drilled the hole, started the EZ out got excited because it started turning and...

SNAP!!!

The f&$%ing EZ out broke! No choice at this point, I hate the thing. So I take it to a friend of mine who builds hot rods for a living and paid him to fix it for me.

He was able to get the now broken EZ out and fitting out of the head. Unfortunately, the reason the EZ out broke was because I threaded it into the head. The EZ out basically cut a leak path into the head.

The final fix, and I'll try to post a pic later, was to weld the OEM sensor port closed and cut a new thread into a blind in the water pump. By far and away this is the most frustrating thing I've had to deal with on this Jeep since buying it. My advice to anyone out there that has to change the temp sending unit is to be very careful not to break it.

[Brasscatz]

Yikes man! Glad it got sorted out though

[4.3LXJ]

Took some heroics, but you got it done

[XJ Wheeler]

Wow timmy, that is quite a bit of difficulty just for a sensor. Sorry to hear it was so troublesome for ya but glad its fixed up.

Sent via messenger pigeon - i talk, he types.

[TimmyTXJ]

the drama may not yet be over. just went for a test drive and was aghast to see my now working temp gauge jump almost immediately to the edge of the "red zone". i drove it around the neighborhood for about 30 minutes but it never moved from that spot. when i got home i popped the hood and its warm but to my recollection not any more than usual. all i can figure is maybe there are different sending units and i have the wrong one? does anyone have any thoughts?

[4.3LXJ]

Jump when you turn on the key or after a bit?

[bruggz351]

:D:D:(:D:D:D
Jump when you turn on the key or after a bit?
what he said.

If it gradually increases, like normal when driving, it could be a gauge issue or ???.
But, if it jumps to the red as soon as you turn the key, that's the wrong sender unit, or your wiring to the new location is earthing somewhere along the way.

Sent from my HTC_PN071 using Tapatalk

[Carves]

X 3

Wrong sensor or wiring issue.