penet05

My engine coolant temperature gauge has started to reflect only C. I think I need to replace the sensor. However, I don't know where it is located. Do I need to have any tools to remove and replace? Also, do I need to bleed the coolant and refill it or can I do it without loosing any coolant? Thank you for your inputs.

442dude

BTW - there are more than a couple of reasons why your gauge wouldn't read anything, the ECTS is only one of them...That being said:

Follow the top radiator hose back to the motor - the ECTS is located right under the thermostat housing. Its got 2 wires on it. Don't go aftermarket - stick with the OEM part on this one.

Do you need tools to replace it? Yes...its screwed into the thermostat housing.

Do you need to bleed the system? Most likely no. Work on it when it is cold and work fast. You may lose a little but you can just dump some in.

I would suggest that if you have not flushed your cooling system lately that you take the opportunity to flush the system, replace the thermostat and replace the ECTS all at the same time. Its good practice this time of year if you're due.

Good Luck....

Papa Bear

It's always a good idea when asking a question to include the year/make/model/engine in your post.

penet05

Thanks for the replies. It is a 2005 Uplander LS/ 3.5 motor.
Today all of a sudden the temp gauge worked flawlessly for several trips. 442Dude what other things may cause ECT failure?

442dude

Sometimes its just the wire works it way loose...other times, if your thermostat is NG your coolant might not heat up enough to make the needle move. Could be a problem with the Body Control Module (although the BCM will usually affect all of the gauges at the same time)...could be a problem with the ECM...

There are a bunch of issues that could affect it, just wanted to make sure we were looking at it with eyes wide open. Since yours started working again, I would definitely check the connection at the ECTS under the hood. It runs at millivolts and the slightest amount of corrosion or a slightly loose makes them go bonkers. If you need to replace it its very easy and its also the cheapest thing to replace of all of the possible issues. The definitely do go bad, I've replaced a couple on different vehicles.

I'll keep an eye out - if you need help or detailed info post away! Its a 15 minute job right in your driveway with a wrench (3/4" I think).

colinzhao

my car is 2009 uplander 3.9 engine, when I drive local and highway, coolant temperature gauge show lower than normal, I changed the thermal stat,but same problem, does some body know the temperature sensor location.is same as 2005

442dude

On our 2008 the gauge should be right at the 12:00 position once its warmed up. You're running below that?

I'll double check the location but on the 3.9 I believe its in about the same spot...since I have one sitting in the driveway its pretty easy to check.

sledge.impy

So when you DON'T drive local and highway, it shows normal?

colinzhao

when I park and no drive,coolant temperature gauge show around at 10 clock position.