After having the radiator replaced with a Jaguar radiator, (still has plastic on both ends) I smelled some coolant. I kept checking for weeks and would top it off with 50/50 Ford orange coolant as needed. There was never a puddle under the car nor any stains around the radiator or heater hoses, but the smell was definately there. I called the mechanic to let him know about the smell.

Today, I happened to see a small shiny reflection of light around the thermostat tower. This surprised me, because I had that replaced at 60k miles. Now it has 124k miles and could it leak again

How many pints of coolant can be in a pool on top of the engine?

It is very crowded around the thermostat area. How much labor is involved to remove things to fully diagnose exactly what is leaking?

Also the color is green while because the mechanic told me they filled it with Dexcool. Could that be incompatible with Ford orange coolant?

 

The plastic thermostat housings can and will fail in the 64K miles since it was replaced. There is also a small hose that runs under the manifold to the throttle body that can fail. Everyone is using the aluminum replacement housing these days. Paint it black as a shiny housing on top of an otherwise black engine looks out of place. Removing it is somewhat of a challenge due to the two rear bolts on the housing but I and lots of others have done it. You will need a 10mm crows foot wrench, a 1/4" drive 10mm socket ground down or a 10mm box end wrench bent 90 degrees to get to the bolts. I would not recommend lifting the intake manifold for access. Other than those two bolts everything else is easy. I cut a blade screwdriver slot with a Dremel tool into two of the bolts to make running them down with the screwdriver quick and easy. Others have replaced then with Allen bolts.

On the coolant question, I think the long and often discussions on that subject are far overblown. You are going to be flushing and replacing the coolant so put the correct one in and forget it.

A reoccurring recommendation is to cut the 'jiggle valve' off the new thermostat which will allow the system to bleed trapped air much better.

Just another opportunity to give your car a little loving on Valentines Day.

 

Thanks for the insights and info.

My mechanic thinks that the leak is just from the cap on top of the thermostat housing.

He is going to replace that and retest.

If that is the only thing, the aluminum housing can wait

 

I have the aluminum housing and am not impressed. The URO housing comes with a paper 5 hole gasket and the Jag plastic housing has a round rubber gasket. The URO housing I had leaked from day one on top because the machining at the top of the housing is crap and the supplied gasket for the cap is crap. here recently the gasket on the base has begun to have seepage.

I ended up with the plastic cap on my aluminum housing so it would stop leaking. And lastly on my 99 I had to insulate the fuel line because of the heat build up on the aluminum.

 

DaddyO: There are more than one source for metal thermostat housings. Where did you purchase your housing?

 

I got mine thru Car Quest and the brand was URO. That is good to hear there are others. May be I should have shopped around more. But who knew!

 

I replaced my housing early and put together a little procedure that might help http://www.gusglikas.com/AutoRepairTherHousing.htm I got my parts from http://www.motorcarsltd.com ask for Ken in the parts department, but if you go to the VENDERS link on this page you will also see others that can provide you the parts you need.