Radiator Reservoir Dropping

[ArizonaEnergi]

The water level in my radiator reservoir keeps dropping.  It was at the minimum mark when we bought it with 50 miles on it, and now with 400 miles (150 ICE miles) its about 1" below minimum.  Normal or something to take it in for?

Edited March 21, 2013 by ArizonaEnergi

[plus 3 golfer]

Not normal.  It's a sealed system.  Mine was above the minimum level when purchased and it appears to be the same at 3200 miles.

[ArizonaEnergi]

Update on this.  My OP was made after a 150 mile trip.  When I got a chance to examine the reservoir in detail I decided it had only dropped 1/4"-1/2" over the trip, but was now below the Minimum mark.  Since I was unable to locate Motorcraft Orange antifreeze in Wal-Mart and an auto parts store, I stopped at a Ford dealer and was preparing to spend $22 for a gallon of 100% antifreeze (no water blend) when the clerk upon hearing my story suggested I let the Service dept top it off, and monitor it on our remaining trip (150 miles).  So I did that, and it appears there was no additional loss.  So I suspect it was just air in the system.

 

One thing I did learn is that there is no radiator cap.  The pressure cap on the reservoir is the only way to add antifreeze, and it is indeed a completely sealed and pressurized system.

[plus 3 golfer]

Good there is apparently no issue.  

 

The best time to check coolant level is when the coolant has cooled.  The expansion tank level can vary based on coolant temperature. So there could be a measurable difference if one checks right after shutdown (200+*F)  vs when the coolant is at 50 * F.   When the coolant level is proper, air only gets in the system if one opens the coolant circuit or it has a leak.   When the engine and coolant is at ambient temperature the level should be very consistent and at or above the minimum level. 

[Hatchman]

Sounds like an air bubble. You should be good. You can smell leaking antifreeze, very sweet . Or look for drips under car or on the under engine tray. If the engine was burning it ( leak head gasket) there would be white exhaust smoke.

 

But you should be fine , just a bubble in the system that worked its way out to the reservoir.

[JohnTrigger]

The "problem" with looking for drips under our CMaxs is that the underside of the engine is completely covered by a panel for aerodynamic reasons.  Thus, I suspect an oil or antifreeze leak that is just a few drips every so often is going to go unnoticed, as the panel will hide the drips for quite some time. 

[Hatchman]

The "problem" with looking for drips under our CMaxs is that the underside of the engine is completely covered by a panel for aerodynamic reasons.  Thus, I suspect an oil or antifreeze leak that is just a few drips every so often is going to go unnoticed, as the panel will hide the drips for quite some time. 

 

Yes, which is why I said look "on the under engine tray".  Drip tray, panel, aerodymanic shield, what ever you want to call it.

 Look on top of the panel, which means you'll have to take the 8 screws out to look and see what has dripped on it.  Only takes a few minutes. 

Edited March 23, 2013 by Hatchman

[JAZ]

Sounds like an air bubble. You should be good. You can smell leaking antifreeze, very sweet . Or look for drips under car or on the under engine tray. If the engine was burning it ( leak head gasket) there would be white exhaust smoke.

 

 

Guess my nose isn't that sensitive:  I always 'taste' to make sure.  WARNING:  Antifreeze coolant is highly toxic and very sweet.  Keep away from children and pets at all times.