Hoping for some input here. I have my suspicions, but I'm not an expert on cooling, and I'm not a professional mechanic, so I thought I'd see what others have to say.
This is for my 2010 Fusion with the 2.5 Duratec. I use Torque Pro on a daily basis on my Galaxy S3 'car dash' to monitor everything so I notice when things seem 'different.' The thermostat in this car is a 190F thermostat, and from what I've read, it's supposed to be completely open at ~208F. The coolant system is 'reverse flow.'
Okay, so I drive a lot. Most of my driving is highway, and I commute 55 miles each way, about 52 of which is highway. I see some rush hour bumper-to-bumper traffic regularly, but most of the driving is pretty clear.. usually cruising between about 70-75 mph. Typically, during highway cruising, I see coolant temps fluctuate between 194 and 201 degrees F. There are times it seems to hover lower (186-192), and then other times it hovers up higher (203-206).. doesn't seem to follow any real rhyme or reason.
Today, on my drive in, ambient temps were between about 70-72F, and my drive was pretty standard.. and shortly after I got onto the highway, coolant temps got up in the 203-204 range, and didn't seem to want to come down from there, whether I was going 75 or slowing down to merge, etc.. Then, at one point, I hit an incline with some traffic, and things came down to a crawl. When I hit the top of the incline, the engine was at 208.4F, and traffic opened up (This is normal in this spot - 101 loop north @ Cave Creek road.. there's a backup because of the exit). So I got to the top of the hill, traffic opened up, and I started to speed up again.. and within about 40 seconds, the temps were suddenly down to 183F.. and rose back up and stayed between 186 and 197 until I got off the highway about 12 miles later.
There are also those days when the same trip never sees the coolant get over about 190-192.
I know the way these thermostats are built, when they fail, they're supposed to fail open.. resulting in a 'temp below operating range' code.. but this is not what's happening.
My gut says that the thermostat is either sticking, like the spring is binding, or the shaft/guides are catching.. or it's grown 'lazy'
At one point, I even thought that perhaps some kind of foreign material had come loose inside the cooling system and was occasionally lodging itself in the thermostat or some other passage.. although this seems unlikely, as anything big enough and solid enough to cause this would probablyl also either sieze up the water pump, or lodge for good in a smaller passage somewhere.
What does everyone think?
This is for my 2010 Fusion with the 2.5 Duratec. I use Torque Pro on a daily basis on my Galaxy S3 'car dash' to monitor everything so I notice when things seem 'different.' The thermostat in this car is a 190F thermostat, and from what I've read, it's supposed to be completely open at ~208F. The coolant system is 'reverse flow.'
Okay, so I drive a lot. Most of my driving is highway, and I commute 55 miles each way, about 52 of which is highway. I see some rush hour bumper-to-bumper traffic regularly, but most of the driving is pretty clear.. usually cruising between about 70-75 mph. Typically, during highway cruising, I see coolant temps fluctuate between 194 and 201 degrees F. There are times it seems to hover lower (186-192), and then other times it hovers up higher (203-206).. doesn't seem to follow any real rhyme or reason.
Today, on my drive in, ambient temps were between about 70-72F, and my drive was pretty standard.. and shortly after I got onto the highway, coolant temps got up in the 203-204 range, and didn't seem to want to come down from there, whether I was going 75 or slowing down to merge, etc.. Then, at one point, I hit an incline with some traffic, and things came down to a crawl. When I hit the top of the incline, the engine was at 208.4F, and traffic opened up (This is normal in this spot - 101 loop north @ Cave Creek road.. there's a backup because of the exit). So I got to the top of the hill, traffic opened up, and I started to speed up again.. and within about 40 seconds, the temps were suddenly down to 183F.. and rose back up and stayed between 186 and 197 until I got off the highway about 12 miles later.
There are also those days when the same trip never sees the coolant get over about 190-192.
I know the way these thermostats are built, when they fail, they're supposed to fail open.. resulting in a 'temp below operating range' code.. but this is not what's happening.
My gut says that the thermostat is either sticking, like the spring is binding, or the shaft/guides are catching.. or it's grown 'lazy'
At one point, I even thought that perhaps some kind of foreign material had come loose inside the cooling system and was occasionally lodging itself in the thermostat or some other passage.. although this seems unlikely, as anything big enough and solid enough to cause this would probablyl also either sieze up the water pump, or lodge for good in a smaller passage somewhere.
What does everyone think?