Replacing coolant temperature sensor

[EvoStevo]

Is it possible to replace the coolant temperature sensor/sending unit without having to completely drain the coolant?

[jlevie]

Yes. Get the front of the car 1-2' in the air. You'll loose a bit of coolant and will need to re-bleed the system, but that's less work than draining the cooling system.

[EvoStevo]

Yes. Get the front of the car 1-2' in the air. You'll loose a bit of coolant and will need to re-bleed the system, but that's less work than draining the cooling system.

Thanks. I'll try this. Would a rag be sufficient enough for catching the coolant that leaks out?

[bimmerboy12]

I took it out and put my finger over the hole really quick, had the new one ready and put it in... lost a tablespoon or so...

[SlowGoinE30]

So I guess it means I have air in the system if I did mine and no coolant came out.

I'm talking about the blue thermo-time ( whatever its called ) I probably need to bleed the system.

I just had the rad changed, it does seem to run a little hot for a brand new rad.

[yert315]

anytime you mess with the cooling system you will want to bleed it. Make it common practice, or you will have headaches with it getting hot.

It's honestly not that hard, just tedious

[SlowGoinE30]

I didnt do the rad swap or I would have, it was 3ft of snow around here when we did it, I had to bring it somewhere. I'll do it this weeknd.

[EvoStevo]

I replaced the Coolant temp sensor (I think) on my M20B25 and the car starts with every turn of the key now and generally runs much better. However, I broke off the plug on the sensor above the CTS. Is that just a sending unit to the gauge cluster? The only thing I seem to have lost is the temp gauge. The Bentley manual says this sensor also adjusts idle air/fuel mixture and actually is supposed to have two contacts in the plug (mine only had one). I'm really confused, guys. Is this a big deal or not?

[EvoStevo]

Bump. Now my car is acting like it did before. What the hell does this thing do?

[rThor432]

The blue two pole sensor is for the motor electronics. The brown single pole sensor is for your guage cluster. Make sure you've got a working temp guage. That's probably the most important guage in the cluster.

If you park the car on an incline, you can usually just crack the bleed screw and fill the coolant reservoir until it runs out at the bleed screw. You might still have a couple of tiny air bubbles, but it isnt likely that you'll have much bleeding to do.

(I'm not saying to fill and go, always bleed it out right).