Help! Engine coolant sensor snapped off!

[mcc]

My Envoy's running cool (up to 3 ticks to the left of center, confirmed by Torque) so I decided to replace the thermostat + engine coolant temp sensor. I was taking the old one off with an offset 18mm flare nut wrench and this happened:

View attachment 21506

How do I get this thing out? Should I get it towed?

 

[McGMT]

Oh you poor poor man, feel for ya... One thing about it, it wont leak... But, do you happen to have a set of easy outs? Could try those, hit it with some penetrating oil, work the easy out around in there, if that don't work I have another suggestion but you have to be extremely careful with it if you try it...

 

[mcc]

Unfortunately my tool selection here is sparse, I'm home with only this car and I don't have a set of easy outs. I've sprayed it with PB blaster (I did before I started working on it as well).

In my panic after this I didn't even realize that it's not going to leak. Should it be safe to drive without it for 3 1/2 hour trips? I need to get to work tomorrow... If not, how could I rig up the new sensor to report high enough temps for the car to enter closed loop?

 

[Phantom]

My Envoy's running cool (up to 3 ticks to the left of center, confirmed by Torque) so I decided to replace the thermostat + engine coolant temp sensor. I was taking the old one off with an offset 18mm flare nut wrench and this happened:

View attachment 7635iView attachment 7636

How do I get this thing out? Should I get it towed?

Left handed drill bit? Spray it with some penetrating oil and do not try to get it out quick. Take your time. That's what I did when i broke two bolts in the block when changing the water pump.. Good luck!

 

[McGMT]

Unfortunately my tool selection here is sparse, I'm home with only this car and I don't have a set of easy outs. I've sprayed it with PB blaster (I did before I started working on it as well).

In my panic after this I didn't even realize that it's not going to leak. Should it be safe to drive without it for 3 1/2 hour trips? I need to get to work tomorrow... If not, how could I rig up the new sensor to report high enough temps for the car to enter closed loop?

Ummmmm, a resistor put in place of the old sensor would trick it if you knew what resistance 200 deg was.... A short trip would be ok to get it where you gotta go without the sensor but I don't know about a few longer trips, would hate to see ya take out your converter...

 

[mcc]

I DO have a large variety of resistors and soldering equipment on hand. If I knew the resistance I could easily rig something up.

Edit: I don't see how I could get my drill in there

 

[Mark20]

If you heat the old one to about 200F you can get a resistance measurement on the thermister.

 

[MAY03LT]

I DO have a large variety of resistors and soldering equipment on hand. If I knew the resistance I could easily rig something up.

The temp vs resistance chart in the service manual states that:

177ohms = 212degrees
241ohms = 194degrees

So a resistor in that range should do what you're looking for.

Did the sensor turn at all before it snapped?

 

[Wooluf1952]

Did the sensor turn at all before it snapped?

^^^ That.

The brass is soft. You may be able to wedge a screwdriver in there and get it to back out.

 

[Wooluf1952]

I DO have a large variety of resistors and soldering equipment on hand. If I knew the resistance I could easily rig something up.

Edit: I don't see how I could get my drill in there

If you get the right size extractor, you should be able to remove it without drilling.

 

[mcc]

Thanks everyone for your fast/quality replies. I was able to get about 1 full turn before it snapped.

Based on the ranges MAY03LT posted I was able to pick a variable resistor and set it for the 190-195* range- I verified it with Torque. At this point I'm too worried about messing it up further to proceed. I'm having doubts about getting the lower thermostat bolt out and I have to accept the limits of my inexperience with these sorts of jobs. I'm having someone drive it in to a local independent shop tomorrow to get the coolant sensor, thermostat and new hoses installed professionally. It'll be $$$ but at least I won't mess it up to the point of having to get it towed

Update: It didn't start this morning so I set it to 120*, let it idle for a bit, revved it to ~2k to warm it up and set it to 160*F. I've left instructions to let it idle for 2-3 minutes every 45mins to keep it warm until it can be taken in in a few hours. Thankfully the shop's only 7-10 minutes away so it won't run long in open loop.

 

[mcc]

Ok, the damage is in- $270 for:

-Extract the coolant temp sensor
-Replace coolant temp sensor and thermostat (both Delco)
-Replace upper/lower radiator hoses (Gates) and clamps (Precision Brand)
-1 gal coolant

Add $90 for the parts from Amazon and the total for the job comes to $360. Not bad at all!