Replaced Temp Sensor, threw P0118

[ptguy]

Well, they looked at it, he couldn't seem to find anything. I told him to replace the freakin sensor, and as soon as he does and cranks it up, it threw the P0118 code.

P0118 Engine Coolant Temperature (ECT) Sensor Circuit High Voltage

We let it get to normal operating temp, and clear it. The needle stays there as it always had until this problem. So we button it up and I go for my test drive.

At 8 or so miles, it goes down 2-2 1/2 needles then goes back to normal (low speed driving). Then I get on the Interstate and after 2 miles, it goes down 2 needles, goes back, then down 3 needles, them back. It goes on again as I exited and turned around.

I did 80 on the return leg and it only went down 1 needle after 3 miles, but it lingered there until I exited and stopped. It went down one more time (2 needles).

What is this code, what does it mean? I literally missed the 5 pm closing of the dealers to see if it was under the powertrain warranty, by 2 minutes.

What a day. Of course, it is not going down anywhere near as it was yesterday after they put in a new battery.

None of this happened until after it blew the t-stat housing gasket?

And it still had the cold early morning squeak this morning, but was gone before I made it to the shop (1 mile away). The squeak is the same as the week preceding my waterpump blowout.

Thank you in advanced.