The thermostat housing assembly on my 2003 Mercury Grand Marquis GS is an unusual one.

The hose goes into the "cap" of the thermostat housing assembly - under this "cap" is the thermostat and the rubber thermostat o-ring gasket.

All of this sits ON TOP of a large aluminum housing that is bolted to the engine. The bellows of the thermostat actually resides inside of the top of this large aluminum housing. See the attached photo. At the bottom of this large aluminum housing, is a gasket that has failed and is leaking.

The "cap" that covers the thermostat and the large aluminum housing in which the thermostat bellows resides, are all connected to the block by two long bolts with 10mm heads.

I cannot find this large aluminum housing or its bottom gasket anywhere. I have been to various parts stores and this piece is not even listed. The only thing listed at parts stores is the "cap" that sits on top of the actual thermostat.

Can anyone identify what this large aluminum housing is actually called and where I can order it and the gasket that goes at the bottom where the large aluminum housing connects to the block?

I have a small leak but don't want it to become a large leak. The leak is at the BOTTOM of the large aluminum housing where it bolts to the block. The gasket there has apparently failed (car has 168,359 miles).

Thanks,
Richard
email: rdondes@comcast.net
mobile: 732-742-8940

*** please see attached photo...

 

That "large aluminum housing" is actually the Intake Manifold -- if the manifold itself is not cracked, then it's the Intake Manifold Gasket that is leaking.
Replace gasket set with FEL-PRO gasket set -- Part # MS 98007T-1 -- contains 4 necessary gaskets -- costs more, but MUCH improved over the OEM gaskets.