1998 Explorer burning through Antifreeze

[Laurae201]

I have a '98 Explorer, the engine and radiator were replaced in Dec. 2014 by my local Ford dealer. Since then it has been burning through antifreeze - and by 'burning through', I mean I put between 6-8 gallons in it per year since it was replaced, and on par to do the same this year. There are no noticeable leaks anywhere. The dealer looked at it twice and found nothing. My personal mechanic looked at it, found nothing. They referred me to another shop in their group that did a pressure test and also found no leaks. Nothing unusual shows up with the oil change, no smell, nothing apparent. When I fill it up, I fill the overflow tank and in some cases directly into the radiator [since one time the overflow was full but it didn't drain into the radiator and almost overheated on the interstate. Was probably a sediment issue since it has not happened since.] I replaced the radiator cap, no difference. Does anyone have any ideas what is going on? Where is it all going? I'm paranoid to drive without a container of antifreeze in the truck since it drinks it, and am now having issues with the hood release latch not working because i'm lifting the hood so often. HELP!!! Thanks in advance...

 

[Ray Leonard]

Get a test kit to test for blown head gasket. I more then happy to bet that doing the test will show exhuast gas in the cooling system! which primary cause will be bad head gaskets or gaskets ready to blow out. Or you can do nothing and just wait for the gaskets to give out completely, in which the antifreeze you are carring will do nothing for.

 

[MrQ]

Question: Are you seeing white smoke while it's running or under hard acceleration?

The issue could be the lower intake gasket (The lower intake has coolant passages) and that is a much cheaper and simpler fix. Now it COULD be that the when the engine warms up a small leak path appears between the intake port and the coolant passage allowing coolant to be sucked in and burned. And when the engine is cool the leak path seals up again causing a false-positive on the coolant pressure test.

Unfortunately, this analysis can also apply to head gaskets as well.

The fact that the system was not pulling from the overflow tank is evidence enough that you are not maintaining pressure in the cooling system. My suggestion is to test the coolant system while it's warm (NOT HOT) and see if it still maintains pressure (should be around 16psi).

 

[Laurae201]

Question: Are you seeing white smoke while it's running or under hard acceleration?

The issue could be the lower intake gasket (The lower intake has coolant passages) and that is a much cheaper and simpler fix. Now it COULD be that the when the engine warms up a small leak path appears between the intake port and the coolant passage allowing coolant to be sucked in and burned. And when the engine is cool the leak path seals up again causing a false-positive on the coolant pressure test.

Unfortunately, this analysis can also apply to head gaskets as well.

The fact that the system was not pulling from the overflow tank is evidence enough that you are not maintaining pressure in the cooling system. My suggestion is to test the coolant system while it's warm (NOT HOT) and see if it still maintains pressure (should be around 16psi).

No smoke of any kind - and it doesn't smell hot after driving for an hour on the interstate. I had my mechanic give it a good once-over for it's 22nd birthday and they said it looked pretty good. The occurrence of it not pulling from the overflow tank only happened once, and not since, which is why they thought it could have been a sediment clog.

But, lower intake gasket is something that has not been mentioned before, so that's a lead worth exploring. Since the engine was replaced at the same time the radiator was it leads me to think they didn't align something properly. Who knows. Thank you!!!

 

[410Fortune]

if they did not align something properly with a radiator install and all this coolant was hitting the ground I would think one of these mechanics would have spotted that leak by now....pressure leak test, etc
It is likely being burned up by the engine as @Ray Leonard suggested
Going through a head gasket or intake gasket leak...
A lab test of the oil/coolant is a good idea!!!


You can also pull the 6 spark plugs after a hard run and have a look at their tips.....the cylinder(s) with water in them will look way different then the rest...........maybe even wet. This will at least point to which cyl are having water issues

 

[Gary Crist]

Like Fortune410 said, the plug with the leak might even be "cleaner"
than the others too!

Another a$$ biter is when the head has a crack in exhaust port.
But, it passed all the leak tests was magnafluxed but, only leak when it is hot and running!
That dang car was a blue Ford LTD w/ 302 left head. I did that job 2 times.
The last time free and I paid for the rebuilt heads too.

 

[410Fortune]

oh boy do I know that story. After doing heads on a 5.0 twice ($800 invested) I finally determined the engine sucked and swapped that out too... (another $800 invested) only to have the transmission lose all forward gears on the first test drive.... needless to say Ipulled all the good parts off that Eddie and crushed that stupid truck. That was a 98 Eddie Bauer, around here known as "the eddie"
Battle on!

 

[Laurae201]

Get a test kit to test for blown head gasket. I more then happy to bet that doing the test will show exhuast gas in the cooling system! which primary cause will be bad head gaskets or gaskets ready to blow out. Or you can do nothing and just wait for the gaskets to give out completely, in which the antifreeze you are carring will do nothing for.

Thanks - i'll ask my mechanic about this. Crazy question, but it's not in my paperwork - would the head gasket have been replaced when the new engine was put in? Since it all started happening about the same time it's like a never-ending puzzle. I know 'new' doesn't mean good, and there are definitely lemons out there with parts. Thanks for the feedback!!