Thermostat Question

[explorerford1999]

I have a 2000 Taurus 3.0 FFV. I recently changed my thermostat which I purchased from Ford. When I changed it, everything seemed to go smooth at least I thought. The Ford guy said the most common problem is not bleeding the air out of the system. I ran it until the thermostat opened with the coolant cap off, which is how I remember doing it years ago. After the install I had the coolant system flushed, good to go. Started it up on a cold morning, and drove about 10 miles before the gauge started moving. (Highway) In the city seems to run right in the middle where it should be. When I get on the highway it goes all the way down to cold. I figure the thermostat is staying open.

1. Is the thermostat installed correct? When I installed it was hard to keep it in place while trying to bolt the housing on.

2. Did I reverse the thermostat? I placed the core/spring inside the block.

3. When they flushed it, did air get into the system?

4. Defective thermostat?

[explorerford1999]

I just took it on the highway for ten miles. The first five the temp gauge dropped right down to just above cold. Exit the highway, back to normal. Enter the highway and it goes down a little the first 2.5 miles, then down to cold.

[mediaman67]

air trapped in system is my guess - you should be able to burp it fairly easily...