coolant leak 95 windstar

[tjgalvez]

I own a 1995, 3.8L, 120k miles. For the past week, the engine is running hot, no heat and keep on adding coolant. Today, I drained the coolant from the radiator and I replaced the thermostat. While I was adding coolant to my radiator, I notice that coolant is leaking underneath. After several search, I notice that the leak is coming from a rubber gasket just below the thermostat housing. There is a 2 inch long rubber gasket sticking out and I stick my fingers underneath the gasket and I can feel the coolant leaking out when I my son add more coolant to the radiator. Is that the head gasket? If so, can a coolant stop leak additive fix it temporarily. It's our only means of transportation.

[tjgalvez]

anyone?

[wiswind]

I am not sure of which gasket.....as the '95 3.8L has a different intake manifold setup than the '96 and newer.....
They made a significant change in 1996.

So....there are 2 possibilities, which you should be able to figure out.
1 is the lower intake manifold.....where the lower intake manifold mounts to the TOP of the head.
Coolant flows through there....and is a common leak point on the newer windstars.....don't know about the older ones.
I was NOT successful in stoping this leak with a stop leak product.....it DID slow it down though.
HOWEVER my leak was from the coolant passage(s) INTO the intake manifold.....so I had the pressure of the cooling system on one side....and the vaccum of the intake on the other......so....you might get lucky and be able to seal with the stop leak.

The head gasket is between the BOTTOM of the head and the motor block.
A simple leak to the outside......you might get luckey and solve the leak with with stop leak.
If it were into the cylinder....I would not have high hopes.

I was successful with stop leak in sealing up the front cover (aka timing cover) gasket.
I caught it when it was just a VERY slight seepage......and it has held for at least a good 6 years.

I do recommend keeping some stop leak in the cooling system from this point on.....to seal up leaks as they develop.
The best chance for success is to catch the leak at the seepage stage.
I would recommend the Barrs brand of stop leak.

If you are able to add the product into the radiator.....at the lower radiator hose.....(not easy on the windstar though) it will be drawn into the motor better than adding at the fill point on the radiator.
Otherwise.....I would get the liquid form (alluminumn in color) or the tablets (I think tablet would be the best).....but if you use the tablets......soak them in water or 50/50 coolant mix...until they are broken down and mixed in with the coolant.......
Then....add the tablet mix.....or the alluminumn colored from the bottle.....when the radiator is quite low (maybe 50% full) and fill with a 50/50 mix of coolant/water....but NOT to the top.
Then start the motor......with the radiator cap OFF.
Let the motor idle.....but stay with it to monitor temperature.....and watch for leaks.
Let the coolant with the stop leak circulate through the system......will take a while......and you will not be building up pressure in the system like you would with the cap on.
If you see leakage.....watch that point to see if the stop leak will seal it.... (a big leak most likely will not seal).
Once it is sealed.......and you have run the motor for a while......shut off the motor and let it sit for a while.
Then top off with 50/50 coolant and water......and put the cap back in place.....and idle the motor.....and see if the seal will hold.

The point about adding the stop leak as I mention.....if you put it in a full radiator.....the first thing that happens...as the coolant warms.....but before the thermostat opens......it expands....pushing the stop leak up into the overflow bottle......and it is not going to seal a leak in the motor when it is sitting in the overflow bottle.

The thing about the leak....it lets coolant out during the heat phase....but sucks air when the thermostat opens and cool coolant enters the motor......

I know that Bars brand is sold many places....and I would go to the trouble to shopping a couple stores to get Bar's brand over another brand.
Bar's will NOT clog the heater core....when used as directed..unless there is something super wrong with it to start with.
Coolant flows through the heater core all the time (unless the system has air in it) and so coolant does not just sit there for super extended periods of time.

If this does not work.....then you are looking at a repair.....but you are not out a super large amount of money trying.
I would not hold hope for sealing a LARGE leak....but a small one to the outside....you have a chance.
If it is into the cylinder(s).....I would not have high hopes either.....but let's deal with what you know first.

As a note.....The link in my signature takes you to a lot of pictures that I have taken of my '96 3.8L....including thermostat area.....including with the lower intake manifold off.....I don't know if it will help you determine what is leaking or not.
I am guessing that it is not the thermostat housing gasket itself that is leaking but something below it?.....
Again.....I am not familiar with the intake manifold setup on your engine.....others here will know.
I understand that you do not have the black upper intake manifold....but a alluminum one...as you don't have the IMRC (2 intake ports per cylinder) in the lower intake manifold.
HOWEVER, I expect that they head gasket will be very similar (but it is NOT the same).....

I also wonder if you have the same funky heater hose connection there like I do......another possible leak point.