coming though the vents is hot air on high hot, but randomly it will come out cool for a while then go back up to hot. fans are coming on when the engine gets hot. i really dont feel coolant flowing though the hoses. and the coolant in the overflow tank will fill up the about the top when hot.

First off, to check if the thermostat is good all you need to do is remove it and drop it in a pot of boiling water. If it opens it's probably good (or at least good enough. If you have a thermometer thats even better. Just get the water to the right temp. Next, there are several ways to check for a blown head gasket (or cracked block/head) without tools.

Is the car running like crap, this is the sign of a blown head gasket. Is the oil or water a milky coffe color. If the car is running bad and the oil is milky this is also a sign of a blown gasket and or cracked head. If the water is milky and your getting excessive pressure in the coolant lines this means a cracked block. The problem is, any one of these can cause any and all of the above problems. Since you said it doesn't feel like there is any presure in the coolant lines, I don't think its the block (the only nightmare out of these problems) It sounds to me like your t-stat is bad, because if there is to much/not enough presure, your heater won't work.

Like I said, I don't think it's as bad as a craked block or even head. But to check for this remove the radiator car (overflow tank) then start the car up. If it bubbles alot and right away your getting exhaust gases into the ratiator system. When you do this look for smoke and smell for exhaust.

I'm not an expert, I've just had all of these problems on differnt cars at one time or another. Good Luck!

umm when i start the car with the overflow cap off i do get some bubbles in the tank, but the oil looks perfect. thermostat works perfect.

say it is the engine how much would a replacement run me???

You might have a small leak on the head gasket but you don't need a $3000 engine job. You still haven't ruled out a system air lock or plugged heater core. Look at the small picture first. Do some trouble shooting!

okay so i got exhaust coming out of the overflow tank. i have hot and cold coming out on high hot. it just switches up. i dont see how to check the heatercore with it off for a clog. and what is the solution for an airlock?

Raise the front tires off the ground / ramps are fine.
Start the engine-let it get to full temp. Leave the cap off the expansion tank and watch for circulation. Massage the rad hoses as well during the process. Turn the heat on full and the fan on 4. If there is air it will eventually pushed to the top of the system. Keep feeling the vents for heat quality.
What does you temp guage say at full temp. Is it over the R, A, L, ??

i'll give that a whirl tommorow, it usally wont overheat just sitting there. when i touch the hoses i usally dont get much flow over by the tstat

This may be a silly question. Is the thermostat in correctly?

yea tstat in correct. so when i turn it on i get bubbles in the reservoir for like 5 seconds and exhaust ish gas coming out of it.

What's the mileage?
Try this: start engine and take off cap to resovior.
While at idle, pull one spark plug lead off and watch what happens in the resovoir. If the bubbling stops completely or gets right out of hand, more than likely the head gasket is leaking around that cylinder.
Getting a service like that done will cost around $1000-$1200.
If there is no change in the expansion tank during this test you can rule out your worst fear.

yea but the worst thing is that the bubbles go away within about 10 seconds so it will be hard checking this out. is this a good sign that they go away quickly

so the bubbles go away quickly so i cant tell. i tried starting the car with only on plug on and everyone one of them allowed the reservior to bubble. when i get the car started the reservior fills up with fluid. i am also having a hard time getting the car started now.

also sometimes after shutting the car off i can hear something boiling in the engine bay...maybe coolant boiling around the engine???

Start the engine with all the wires on and then pull them off one at a time. What's the mileage?

did it it bubbles all the time now no matter which one. and i got like 120k

You are positive the water pump is good, right? I attempted to test mine by pulling the thermostat housing off and moving it and the upper hose out of the way. I also took the thermostat out. Then, I had someone start the car and watched the flow as it came out of the block (only do this with engine cold and get ready for a mess...keep your face away from there, too) On my car, it was just a little bit of flow at idle, like a garden hose near its lowest setting just kind of running out of there with no pressure. Had the helper rev it a little and the volume did increase, but I still wasnt impressed.

Only reason I ask about the waterpump is because my car's heat would blow cold sometimes and warm at other times, but never really hot (Was only warm if the engine was spun up a little bit). Also, since the coolant wasnt circulating in the engine very well, it was boiling in the block and going into the overflow tank in the form of steam. If the cap was off, the radiator cap would purge the pressure every once in a while.

When I got my water pump out it had all of its plastic impeller blades chewed right off of it!

yea i actually did that test the other day and its reeally not flowing hard untill i give it some gas and then it shot everywhere. i really dont feel like taking the waterpump off. about a month ago i had ford put one on so i think its under warrenty so i'll let them do it. should i ask for a metal blade is that how it goes? also when i go to start it the reservoir is empty and upon starting it it quickly fills back up

Hmm... when you say it shot everywhere it makes me think the pump might be OK like you said. Its a really subjective test, hard for a person to tell without seeing another identical car run the same test.

Lets just say that with my own car, when I hit the gas, the water did not shoot out, it just kept rolling out of the water neck, but did it with much more volume. I figured that in order to be able to push coolant through the engine and radiator and the hoses, it would have to have more pressure than what I was seeing, and I luckily ended up being right.

I think someone on here put a metal bladed one on their Zetec, it may have been a GMB or something like that. I don't think Ford makes a metal impellered pump for this engine. I ended up going with an Airtex or something like that. I was in a pinch for time, otherwise I probably would have gotten a metal one.

Good luck man

It's a Zetec... I know my Zetec 'said' it was overheating, it was a bad sending unit. not sure if this was fixed from 95 to the 98....

Does the fan come on when it overheats?

yup fans come on, just don't feel the flow through the lines