When is it necessary to change anti-freeze in 2005 ford explorer?

If there is a crack in the head leading into the crankcase the water could be dumping into the oil. Look at the dipstick. Also, water could be dumping into the exhaust ports. I think you need a mechanic smarter than you or me.

The engine in your Ford Explorer has freeze plugs, also called expansion plugs, mounted in the sides of the block. Freeze plugs are supposed to protect the engine block if the water in the engine freezes -- the expanded water is supposed to push out the freeze plug, although that doesn't always happen. Freeze plugs are made of thin steel compared to the engine block, and even with an anti-freeze mixture the plugs can rust out and require replacement.

Read more: How to Replace a Freeze Plug on a 1992 Ford Explorer ' eHow.com http://www.ehow.com/how_7670495_replace-plug-1992-ford-explorer.html#ixzz2IBxfNrjb

Need more info,Amber. Is it water or anti-freeze? Which side of the engine? Are you seeing a drop in the level of anti-freeze in the expansion tank where you add the anti-freeze? Is this a 4.0 V-6 engine or a V-8 engine?(:^) don-ohio

YOU MAY HAVE A BLOWN HEAD GASKET THE CYLINDER HEAD WILL HAVE TO BE REMOVED TO REPLACE THE GASKET. ALSO THE HEAD SHOULD BE PREASURE TESTED FOR CRACKS

1. 1 Drain the coolant from your Explorer into an adequate container by opening the drain plug at the bottom of the radiator. Save the coolant for reuse if it is relatively new and clean.
   
2. 2 Remove the negative battery cable from the battery if your Explorer has a 2.9-, 3.0-, 4.0- or 5.0-liter engine. This step is not necessary for 2.3- and 2.5-liter engines.
   
3. 3 Follow the upper radiator hose to the front driver's side of the intake manifold, where it meets the engine. This is where the thermostat housing on your Ford Explorer is located. If necessary, remove the air cleaner duct for easy access to the housing.
   
4. 4 Loosen the clip on the end of the radiator hose and pull the hose off the thermostat housing. Use a 10mm wrench or socket to remove the two retaining bolts on the thermostat housing cover. Remove the cover.
   
5. 5 Note the position of the thermostat before removal. Pull out the old thermostat. Seat the new thermostat inside the housing in the same position as the old one, spring-side facing into the engine. Install new gasket over the thermostat.
   
6. 6 Reattach the thermostat housing cover and the radiator hose. Reinstall the air cleaner duct if removed earlier. Fill the radiator with reserve or new coolant. Start your Explorer and run with the heater blowing until the engine gets warm. Check for leaks.
   

Read more: How to Change the Thermostat in a Ford Explorer ' eHow.com http://www.ehow.com/how_4484916_change-thermostat-ford-explorer.html#ixzz1CLSvmPwR

OK, recheck the anti-freeze level and fill if necessary. There may be a leak in the system.
If it is filled up to capacity (also check that the upper radiator hose is full of fluid by squeezing), then the next thing to check is the two heater hoses that enter the firewall for the heater core. If they aren't getting hot at normal operating temperature, the heater core is plugged up and will have to be flushed or replaced.

If the heater core hoses are hot, then a blend door problem exists for shuttling hot air from the heater core to the interior of the vehicle.

Good luck on this repair.

Ask your neighbor to come over and read your owners manual to you. Pay him 50 bucks.

DOT Type 3 or better. Look at the brake fluid cap - it will tell you there.

Anti freeze? Go to your full service auto parts store or your authorized Ford Dealer to get the proper anti freeze for your Expedition.

thanks for your question at FixYa.com

Hi ...i suggest changing your head gaskets ...it will come in a complete kit ....do it all ....just looking at a gasket ..some times it hard to tell .....once you take the heads off always change the gaskets ...never will properly seal again ....

YOU COULD HAVE A BLOWN HEAD GASKET, MOST REPAIR SHOPS CAN DO A BLOCK TEST WHICH WILL TELL YOU IF HEAD GASKET IS BAD, ALSO CHECK TAIL PIPE FOR WHITE COLOR SMOKE.