Thermostat Rating
Mackab
12-05-2005, 02:22 PM
While Im buying parts, I might as well get a new thermostat. What rating is required for a 2000 Windstar 3.8L? Parts shopping shows various temp rating such as 195, 197, 185, and 180. Vehicle manual shows the following requirements:
Starts to Open: 183-190
Fully Open: 210
Which temp t-stat should I get?
Starts to Open: 183-190
Fully Open: 210
Which temp t-stat should I get?
phil-l
12-05-2005, 03:52 PM
I just replaced the thermostat on my 2000 Windstar LX 3.8 yesterday.
My original, OEM thermostat was marked 192 degrees. The aftermarket replacement thermostat was marked 195 degrees.
The replacement was the standard replacement from my local Autozone; they looked it up. I didn't look into changing the temperature. The engine runs fine; temperature gauge rises to the location I'm used to seeing.
I don't believe the 3 degree difference is significant, I just want the thermostat to work correctly (OEM got stuck open periodically).
I would stay as close to the originally specified temperature as you can. In the old days, cooler thermostats were a way to potentially boost performance. Overly cooling a modern engine can cause engine control problems (mostly emissions related; the controller thinks the engine isn't warm enough to go into closed-loop mode and throws a CEL).
Other hints:
- Make sure to ask for a gasket. My thermostat didn't come with one; it was a separate item.
- This is also a good time to flush the coolant system. I drained the system using the radiator petcock (look below the battery; it's white), lower radiator hose (near the oil filter), the thermostat housing itself and one of the rear heater lines. I also removed the heater supply line just next to the thermostat housing, which made it easy to flush the rear lines. If you remove the heater supply line, note that there are *two* O-rings in there. I almost missed the second one (it got stuck inside the line). Also note that the O-rings were pretty cruddy; I removed them (and the plastic spacer) and cleaned everything up. A light coat of dielectric grease helped re-assembly.
- I also removed the coolant reservoir and cleaned it. Lots of gunk in the bottom.
- It takes awhile to get rid of air in the heater cores. I spent time going up and down the most hilly local roads I could find, topping off the reservoir as I worked the air out.
Phil
My original, OEM thermostat was marked 192 degrees. The aftermarket replacement thermostat was marked 195 degrees.
The replacement was the standard replacement from my local Autozone; they looked it up. I didn't look into changing the temperature. The engine runs fine; temperature gauge rises to the location I'm used to seeing.
I don't believe the 3 degree difference is significant, I just want the thermostat to work correctly (OEM got stuck open periodically).
I would stay as close to the originally specified temperature as you can. In the old days, cooler thermostats were a way to potentially boost performance. Overly cooling a modern engine can cause engine control problems (mostly emissions related; the controller thinks the engine isn't warm enough to go into closed-loop mode and throws a CEL).
Other hints:
- Make sure to ask for a gasket. My thermostat didn't come with one; it was a separate item.
- This is also a good time to flush the coolant system. I drained the system using the radiator petcock (look below the battery; it's white), lower radiator hose (near the oil filter), the thermostat housing itself and one of the rear heater lines. I also removed the heater supply line just next to the thermostat housing, which made it easy to flush the rear lines. If you remove the heater supply line, note that there are *two* O-rings in there. I almost missed the second one (it got stuck inside the line). Also note that the O-rings were pretty cruddy; I removed them (and the plastic spacer) and cleaned everything up. A light coat of dielectric grease helped re-assembly.
- I also removed the coolant reservoir and cleaned it. Lots of gunk in the bottom.
- It takes awhile to get rid of air in the heater cores. I spent time going up and down the most hilly local roads I could find, topping off the reservoir as I worked the air out.
Phil
garync1
12-09-2005, 10:16 AM
also depends on were you live.. They say up north a higher opening temp down south they say a lower opening temp.. I live down south so I always got the lower opening temp..
LeSabre97mint
12-09-2005, 02:12 PM
also depends on were you live.. They say up north a higher opening temp down south they say a lower opening temp.. I live down south so I always got the lower opening temp..
Hello
I thought that I'd add my :2cents: here. Keep in mind that the engine computer monitors the temp of the engine and adjusts the fuel mixture and timing accordingly. Most engines designed today were made to run around the 195 mark. The engine parts are designed to expand to a certaion size at operation temperature.
Too cold of a thermo will burn more gas.
Regards
Dan
Hello
I thought that I'd add my :2cents: here. Keep in mind that the engine computer monitors the temp of the engine and adjusts the fuel mixture and timing accordingly. Most engines designed today were made to run around the 195 mark. The engine parts are designed to expand to a certaion size at operation temperature.
Too cold of a thermo will burn more gas.
Regards
Dan
Automotive Network, Inc., Copyright ©2026