Question about 1999 Ford Expedition
I have a 99 expedition that is leaking coolant from a line on the passenger side towards the back. This is causing the car to overheat. I think it is one of the lines for the rear heater core. If I bypass the rear heater core, will it solve the problem for now, or do I have to replace the lines? Thank you!
You have to replace them or you can bypass them but there will be no heat in the back did someone put stop leak in if so it clogs the whole system up and causes the weak spots to let go is the heater core clogged most likely and replacement with new lines is a + for the truck and passengers if the leaks from vibration causing the line to rub away then just replace the line depending on the size of it you might be able to use a compression union X2 and a new line but if it's stop leak it has to be flushed a real lot and still that stuff will be in there you must drain the whole system and use phosphoric acid it will get that out and it's available at home Depot or you could use Pepsi or coke it's in theregards and I'm not joking it works also lemon juice and water but mistly juice will eat that stuff then baking soda to neutralize the acid works the truck has to run e couple of hours with it then a high pressure force flush with clean water also laundry detergents work but take longer and sometimes rust will start but could be used after everything else again followed by a high pressure flush for about 15 min so good look I'm not there so I can only tell you probable causes you have to know if the stop leak is in there it either looks like sand or like a redish brown gunk I hope for your sake that this is not the case it's very troublesome to get out and if your mechanic did it it's even worse troublesome because he or she is supposed to know better then to use that unless they are dishonest and that stuff will keep you coming back for more repairs and more $$$$$$$$for them good luck again stephen
Posted on Jan 03, 2018
the heater bypass is quite simple, if you look at the firewall you will see two medium sized coolant lines, remove them from the firewall and link them together using a proper sized tube, you can purchase a kit at a parts store quite cheaply
Posted on Oct 11, 2008
Those codes are for the oxygen sensors, lean fuel mixture on both banks. Change them, problem with stalling and rough idle should go away.
Posted on Apr 23, 2009
check closer to just underneath the firewall--it could be a smaller problem than a heater core--Ford 4.6--5.4 engines have a tube just underneath the intake manifold that the rubber hose goes bad and it will leak towards the back of the engine.Lets hope so-what i hear its very expensive to change a heater core in an Expedition.
Posted on May 01, 2009
Sorry im late with this,i couldnt seem to log on....The answer to your question is YES,there is a steel line under the intake with a short piece of rubber line attached to it and you can just about see it from the front of the intake with a light,it can leak and cause coolant to run off the back of the engine,The intake gasket set alone is about $40.00 and i dont know about the rubber line,i have seen it physically but havent changed one yet.Note the date of manufactor just incase,i bought an intake set for a 99 and the engine design was changed half way through...its not too hard to pull off the intake and re-install,you will need a 7mm socket for the coil packs,8mm socket for the fuel rail bolts and lower intake bolts and power steering bracket bolts and throttle bracket bolts,10mm socket for the intake bolts and alternator bolts and egr valve,and a large cresant wrench for the exhaust tube thats connected to the egr valve,flat screw driver for the air cleaner...and plenty of extensions with a swivel to be able to get to the back bolts of the intake....just incase you do it yourself this info could make it easier to gather tools.Its about a 3 1\2 to 4 hour job start to finish for the first time doing it,includes cleaning everything..Good luck
Posted on May 16, 2009
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