motor was swapped out not sure what it is now

[johnunit]

Actually there is no 'police chip' either, the earlier reference to one was a joke.
Some police boxes got carb'ed 351's, but they only had 20-30 more HP than the 5.0.

just to add to this, you'd know if it was a 351W from a police (or some Canadian) Crown Vic

they look like this:


Very different look from the EFI's found in 86 and later crown vics.

[FordMan77]

HOWEVER I am slowly losing antifreeze, about 1 inch every 4-5 days. I cannot see any leaks and the performance does not suffer.

You may want to have the cooling system pressure tested. You may discover your leak.

I just went through this with my Dad's 89 and after changing everything in the cooling system but the heater core, we finally figured out that one of the head bolts on the drivers side had broken and blew the headgasket. The only way we found it is when it overhead once, then the HG started to leak. That and the spark plugs around those 2 cylinders were a bit white. Never even got any sweet smelling exhaust or the white cloud as you typically see when a HG lets go. No warning, ran jsut fine, just mysterious loss of coolant and then the overheat, which was probably what pushed the HG over the edge. A new set of ARP head bolts and HG's and it's running fine.

Just something to think about.

Jay

[sly]

also check the oil. it should NOT look like a chocolate milkshake. If it does... your coolant is leaking into the oil and that's probably a head gasket as well.

also check the drip hole behind the water pump between the pump and the engine itself. see if there's any pooling of coolant there. This means you need a new water pump gasket at least and because they're generally cheap, a new water pump (they come with the gaskets). This is how I found the leak on my Mark VI, but then I could smell a very faint whiff of coolant when I would park after driving for a while.