Changed thermostat, got big leak,

I changed my thermostat in my 2000 lincoln ls, right after the lines would not fill with coolant, i then opened the black cap above the thermostat to bleed the air, it then began to leak really bad from the bottom area of the engine, i couldnt see where it was coming from. what do you believe is leaking and/or what do you think caused it? it also will not kick out any heat as it he.ated up, and i ran 3 gallons of coolant through fast

The most likely leak point, given that it was most recently messed-with, would be the thermostat housing. You did put a new gasket in, right? And you removed the old one and scraped clean the mounting surfaces? Tightened the bolts evenly?

I’d guess if you took the thermostat housing back apart and checked all your work, it’ll take care of it.

I agree with Jack . . . but one part of your post has me stumped . . . the coolant is being lost from the bottom of the engine? Are you sure that it isn’t running down from the t-stat housing and dripping off the bottom? Get underneath (use jack stands please) and locate the exact point of leaking, then post back. The t-stat housing is obvious, but you may have a bigger problem than that if you lost 3 gallons of coolant fast. Rocketman

I agree with the other 2 posts; likely a leak running down from the housing. Why did you change the thermostat in the first place? The only thing that would be leaking from below would be an expansion plug. You won’t have any heat inside the vehicle without hot water circulating. Check your thermostst gasket first.

…Check for cracked t-stat housing