Coolant is missing, MPG is poor. What is wrong?

[accent]

I have a 2010 ford edge with 70k miles. It only gets 18MPG on city driving. Coolant is missing. The coolant resolver is almost empty. Don't see any leaks. Is it a sign of bad engine?

[James Costa]

I am by no means an expert, but if the coolant reservoir is empty, you have a problem. Definitely don't drive it like that... If the head gasket was blown it could have sucked the coolant into the exhaust but you would have certainly seen an obvious performance problem (and probably some white smoke from the exhaust). It could also be a problem with a cracked or broken thermostat housing or hose, or a broken/unsealed radiator. I have seen those as common issues on other cars, not specific to the Edge. Less likely would be a secondary device that connects to the coolant lines, like the heater.

 

As a quick check, you could fill your coolant tank with water and take a look underneath to see if you see any water spillage anywhere.

[omar302]

18 MPG in the City is good and as per EPA ratings.

 

As for the coolant, did you try to fill it up & see how long it holds?

Edited September 22, 2016 by omar302

[WWWPerfA_ZN0W]

Be sure to fill up with 50/50 Motorcraft pre-diluted (could be Specialty Green or Specialty Orange, NOT interchangeable) coolant in the reservoir/degas bottle. You may need to top it up a few times depending on how low the coolant actually is. It should burp itself over time, but if it doesn't and you have temperature control problems, you will need to follow a "burp"ing procedure at that time.

 

How frequently do you check the coolant? Was this the first time?

[accent]

 

 

How frequently do you check the coolant? Was this the first time?

Yes, first time.

[WWWPerfA_ZN0W]

If everything is otherwise working fine, no warning lights nothing, then go ahead and fill the coolant in the reservoir (with engine cold/at ambient and turned off) to the FULL COLD mark. Then drive around like normal and check again when engine is cold & off. Repeat as needed.