Coolant leak(s) at 128k miles.

[sabol]

id like to first state that i do not own an explorer. however i am a freelance mechanic. i currently am fixing all that is wrong with a customers sport trac and one of the issues is a steady leak originating from high on the left bank of the motor. now, today i tried isolating where the coolant is leaking from but, no luck. it just looks like its comming from out of the front of the cylinder head honestly, however i dont believe that may be the issue. now this truck hasnt had a good once over since my customer originally purchased it. so im thinking it may be the water pump gasket or maybe the water pump. although i did notice alot of corrosion on what looked to me like the thermostat housing (is it plastic and right under the intake?) however it wasn't leaking from there. should anyone have a picture of the front of the 4.0 v6 that would be a huge help. im doing all of these repairs in his driveway and he looms over my shoulder at all times. not that it discourages me seeing as i am experienced, but it does make me second guess my better judgment. he also complained of smelling antifreeze in the cabin, which obviously would be the heater core, could both of these issues be happening at the same time? when does the heater core usually need replacing on these vehicles? thank you all again for your assistance as it seems from browsing the forums here you all know a great deal about this platform. (i've seen the 5.0L sport trac sticky and thats damn good work! so i trust i will get pointed in the proper direction!)

i await your replies and god bless.

 

[600remguy]

Do the pics in the "water jacket" posting help at all?

 

[Chronicrage]

yeah see the water jacket posting..sounds like it could be the "expansion plug"

 

[ncranchero]

The thermostat housing it a 2 piece design. My guess would be lower thermostat housing leak.
How to replace upper & lower thermostat housing

 

[sabol]

that actually sounds like that might be it. I'll have to take off the intake and poke around, see if that might be where its leaking. the corrosion is definitely of the glycol based variety, however its right where the top and the bottom on the housing bolt to. nowhere else. but what you're saying is that the bottom of the housing bolts to the engine, and that the seal there can fail? Is there a gasket for it? or would i need to make one using RTV sealant?

 

[ncranchero]

Did you click the links I included?

PM me your email address and I'll send the instructions from the Ford manual to you in pdf. Be sure to include the year and if Flex-fuel or not.

 

[sabol]

yes, im actually reviewing the lower t-stat housing deal now. and after seeing the shape and orientation of the part, and seeing that its actually a common failing point, that has to be it. very helpful. im actually calling my customer now and going to ask him to deposit part money into my account so that i can order the parts.

 

[ncranchero]

Let us know how it turns out!

 

[sabol]

i will. im currently putting a price list together for my customer and then i'll be ordering the parts... once they come in, i'll be installing them. thanks again guys...

i'll photograph and video log (well, bits and pieces of it.) the process

 

[sabol]

ok just before ordering parts i noticed the difference in part numbers. the lower thermostat housing has two different part numbers... one being RH144 and RH148.. what are the differences between these two housings? i would rather not order the wrong part. thanks in advance guys.

 

[sabol]

and let me add that i just noticed the uppers have two different part numbers as well.... RH147 and RH165.. whats the difference between these two as well? and what the hell was ford thinking in producing such an array of replacement parts? wouldn't it be more cost effective to make something like this a simple only-one-kind-of-replacement-part instead of producing multiple pieces that could easily be mistaken for others? it seems im going to have to drive over and get his vin number.. unless he can read it off to me in the morning.

 

[600remguy]

Not positive, but it may be the number of sending units on the top piece. Some have 1, others 2. Just about everybody orders new sending units as well. Somewhere to start-hopefully someone who knows for sure will chime in.

 

[ncranchero]

You didn't specify the year of the Sport Trac you're working on, that I see, so go HERE to the Motorcraft online catalog and look up the correct part number by application.