Ok I have a 1990 ford thunderbird 3.8L NA and last year I was having problems with the needle goin crazy hot cold..... so I changed the thermostat and water pump. IT was all fine till today i get on the expressway and it goes HOT and the heat isnt working....
I popped the hood and there is coolent coming out of the overflow tank.... and then the coolent was going down after the car was turned off.
What could this be.....please tell me its not going to need headgaskets. It has 200K on it and im sure they were changed b4 i bought it.
Classic symptoms of blown head gaskets, Jay. Not a hard job to do with a shop manual, some decent tools and a little time. Make sure you get the heads resurfaced AND pressure tested by a machine shop. See my article to see why !CRACKED Also check the block area around where the gasket blew for any signs of erosion. ThunderCentral.
Sounds like a cracked head to me!! the way it goes back and forth from hot to cold, then all of a sudden overheats.. my 90 3.8 LX did that too.
whatever you do.. dont let the coolant sit in the block!!
My 92 blew hg's, and I let it sit for 2 years before finally fixing it which was a month ago.. the car runs now, but just developed a knock in the past few weeks!! and that was after a new timing chain and other crap too!
mine did the same thing when my HG went. It was bubbling out the overflow. you could pull you plugs after it sits over night and see if any coolant comes out. i had some coolant come out of one of my cylinders.
How cold was it? Do you have enough antifreeze in the system to prevent freeze up. A frozen system could also cause exactly what you were describing and then when it thaws out everything may be just fine, or it may have cracked expensive parts.