Need Help with Coolant Leak

[Matthew S]

I have had a small coolant leak for about a year now and have just now found it I think (I am only home 1 day a week each week, so my time is really limited). Anyway, I have one of the first ST's off the line (2001), and I know my thermostat housing area is a little different from most based on my research back in 2003/2004 when I had to replace my thermostat at 36030 miles.



Anyway, the picture is taken standing just in front of the battery housing and looking towards the passenger side. There seems to be dried/crusted coolant in the immediate area of the thermostat housing and whatever sensor this is on the backside of that housing. I believe the rusted area at the base of the sensor is the cause of the leak as it has the most rust present. It's that, or that's where the coolant puddled the most.



Either way, any opinions/advice on what sensor part this is exactly and what parts I should replace? I am going to go ahead and replace the thermostat and I can order a new thermostat housing, but I am not sure what all pieces within the picture that housing would include. Has anyone had to work in this area before? Appreciate any and all help.



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[Richard L]

You should only need to replace the thermostat and gasket. However, when you have a leak, it's always best to have the system pressure tested with a dye in your coolant...That takes all the guess-work out of it.



If a sensor is leaking at the base but is working otherwise, you should just be able to put a little sealant on the threads and screw it back in.



If your Sport Trac has the original hoses and belts, you should replace them. They start to go bad in 3-5 years...beyond that they are living on borrowed time and can easily leave you stranded on the side of the road...or worse



...Rich

 

[Fudged Undies]

I would also suggest getting some degreaser or engine cleaner and cleaning that area so the leak will be a bit easier to detect visually. Since there is just rust there I wouldn't be so quick to jump on a leak. Have you noticed a loss of coolant? Have you seen any coolant leaking?



May just be rust not related to a leak. The thermostat housing is plastic and lower part where the two sensors in you pic plug into has a seem that will unglue and leak. I had this and I know of another member here who has had it. It's a pain to change and the part is not a dealer stock item.



The part you label thermostat housing is actually the T-stat cover.



The ?? part is one of the temp sensors. There is another, don't recall if it's behind the one pictured or to the left.

 

[Matthew S]

Yes, there has definately been coolant loss and a burning smell that I couldn't find for the past year or so. So when I finally saw this, I came to the conclusion that the leak must be in this area. The encrusted fluid is what caught my eye, and then the rust.



So if I order a new Thermostate housing, are we saying that that includes the whole black/grey plastic part from the bolts on the left side of the picture to just past the rusted sensor on the right side of the picture?



Has anyone replaced all the radiator hoses on this engine? The upper radiator hose alone is a combination of 3or4 hoses tied together with inline metal tubing where it runs close to the engine block. I guess I am gonna have to spend quite a bit of time at the Napa shop making sure I get all the hoses ordered if I want to replace all coolant hoses. I don't see any info at all on this site about the hoses. Am I missing something?



Again, appreciate your help.