Overheating

[SteveF]

Wife took the Fiesta on 200 mile trip on highways. On arrival car sat in 102 degree temp for about 3 hours. Got back in the car and drove in traffic for about 15 minutes when she got the coolant temp warning and idiot light. Stopped car. Opened hood and said she saw coolant in the reservoir boiling. Waited a few minutes and then carefully opened reservoir. Said all the water was gone. Friend came and said they added about 1/2 gallon to reservoir. Next morning she took it to a shop. They test drove it but found no problem. Pressure tested it overnight and no leak. Test drove again next day and still no problem. Wife drove back home 200 miles and has been driving it for a week in 100 degree temps in traffic with no recurrence. Only thing I can think of is that either the electric fan is intermittently failing of the sensor that controls the fan is failing. Parts schematic only shows the thermostat. Is the electric fan sensor built into the electric fan housing or somewhere else. Any other ideas of what could cause this or how to find fan controller?

 

[SteveS]

It may have been that the car was low on coolant.

 

[SteveF]

It may have been that the car was low on coolant.

Since the cooling system is a totally sealed system and the pressure test was left for over 8 hours and did not lose pressure I do not see how the water could have leaked out. Also, since she returned I have monitored it very closely and the level has not gone down at all and there is no evidence of a leak anywhere. I was hoping that it was just a hose leak but I do not see how.

 

[SteveS]

Since the cooling system is a totally sealed system and the pressure test was left for over 8 hours and did not lose pressure I do not see how the water could have leaked out. Also, since she returned I have monitored it very closely and the level has not gone down at all and there is no evidence of a leak anywhere. I was hoping that it was just a hose leak but I do not see how.

If the reservoir was empty, it was low on coolant. It's a closed system. It doesn't spit out coolant when overheated. How it got low is the question. If the car ever had the coolant replaced the likely answer would be that it was never filled all the way and had an air bubble somewhere that wasn't burped out.

If it hadn't been low but a half gallon of coolant were added, it would be overfilled and overflowing.

 

[WannabeST]

If the reservoir was empty, it was low on coolant. It's a closed system. It doesn't spit out coolant when overheated. How it got low is the question. If the car ever had the coolant replaced the likely answer would be that it was never filled all the way and had an air bubble somewhere that wasn't burped out.

If it hadn't been low but a half gallon of coolant were added, it would be overfilled and overflowing.

I agree with this statement.

 

[Carrottwap]

Hey all, new to the forum. I have an issue hoping y’all can help and/or point me in the right direction. I have a 15 fiesta st. OEM coolant reservoir had a crack so I ordered one online. The reservoir I ordered is a Dorman 603-381 multiple sites say it’s “factory fitment” however the 2 smaller lines won’t seat fully. One is the line that goes to the turbo and the other I believe is the return. Has anyone had similar issues with this?

 

[akiraproject24]

Hey all, new to the forum. I have an issue hoping y’all can help and/or point me in the right direction. I have a 15 fiesta st. OEM coolant reservoir had a crack so I ordered one online. The reservoir I ordered is a Dorman 603-381 multiple sites say it’s “factory fitment” however the 2 smaller lines won’t seat fully. One is the line that goes to the turbo and the other I believe is the return. Has anyone had similar issues with this?

Sort of...

I ordered the Dorman reserve tank for my Ford Focus once. SImilar tank but my Focus was normally aspirated one. Anyhow the small lines that clip in constantly were wet and didn't give a good seal. I initially wanted the Dorman OVER OEM because i liked the metal insert it had. Wont buy anything but OEM now or possibly an aftermarket metal tank like Airtec or ProAlloy.