Ertman

Replaced the thermostat and the engine coolant temp sensor.

I did the ECT first. After it was done, the temp guage started acting like the t'stat was sticking, so I just got finished replacing the t'stat.

Bleed the system of air and took it for a spirited run. The temp gauge rose to the "12 o'clock" position just like it used to, but after a couple of minutes of unobstructed airflow, it dropped down to just below the second notch.

a4avant99

I have had a similar problem. I have replaced the T-stat first. The problem was fixed. But it began once again a month or two later, and I have replaced the temperature sensor. The problem never come back since.

I would suggest you to drive a few weeks before doing anything. If the temperature needle rarely arrive at the 12 o'clock position, and stably remain at a lower position, replace the T-stat first. If the temperature needle arrives at the 12 o'clock positioon and then (maybe after a few hours, maybe after a few minutes, not predictable) drop to almost 9 o'clock, replace the temperature sensor first.

If the temperature is lower on high way than local driving, it's most likely a problem of the T-stat.

Ertman

I am going to let it be for a while and see how it does. Today it did both.

Koolgreen

is there a procedure for changing the stat?
ie part number and what other parts are needed ie the gasket or oring or whatever.

I have been told that the stat is on the lower portion of the hoses.

a4avant99

You will know when you are below the car.

I bought both the t-stat and the ring, but a ring came with the t-stat.

kgardnez

I was havign some similar problems and it turned out to be dirty contacts on the temperature sensor on the radiator. This sensor is located (on the 1.8t) on the drivers side about 4" from the bottom of the radiator.

Ertman

I will look at it in the morning, that is one sensor I haven't checked yet.