A few weeks back I was doing a routine under the hood check for oil level and any thing else which may catch my eye. I have a 04 explorer with the 4.0 engine. I noticed the coolant level was low and started to check for leaks. The plastic thermostat housing was leaking so I ordered the part off the internet and replaced it. So far no leaks in that area. I have noticed the coolant level has dropped slightly. Is this normal and just air working it's way out of the system. No leaks on the ground or any smell of antifreeze. I topped it off tonight and will continue to monitor the level. When would be the best time to check it, I was thinking probably first thing in the morning when the engine is cold. My concern is it's going on a 2000 mile road trip in a few days and I don't want to worry about coolant level. I have another car I could take but would prefer to take the explorer. Thanks for your help in advance.
Replaced thermostat housing on 04 explorer
- Thread starter kwijibo
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Yup, could have been air in it. Cold in the morning is the most repeatable, but you could also do a mental mark (or sharpie mark) for expected hot level on the overflow tank.
Generally after I do coolant service I moderately overfill the overflow tank, expecting it to drop as it burps air out.
Generally after I do coolant service I moderately overfill the overflow tank, expecting it to drop as it burps air out.
most likely its just air
Yep when I flush my coolant it takes a day or so to level out. It always fluctuates from hot and cold too. I always check mine cold.
Probably just air but we had an 05 4.0 and around 100,000 miles the radiator started leaking very slowly. Only when driving, made it hard to detect.
Did you replace the whole thing or just the lower housing? Also what brand did you use? We have found that anything but Motorcraft will leak, and not replacing the entire housing will result in leaking again.
I replaced the whole housing with one built by Dorman. They claim to be better then OEM and I bought the story hook line and sinker. So time will tell, right now the level is holding. If it leaks again I'll go back to Motorcraft. It took less then an hour to replace. Of course with my luck if it leaks again it will be in the middle of winter in MN, Again thanks for the help.
It may be air escaping the cooling system.
However, sometimes when you replace the one part that leaks, the added pressure in the cooling system makes the next weakest part leaks.
However, sometimes when you replace the one part that leaks, the added pressure in the cooling system makes the next weakest part leaks.
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