Coolant leak?

Just replaced this engine with a used dohc engine
The car barley drives down the street but after 15 to 20 minutes of idling compliant start to rise in reserviour and then start coming out from under cap coolant is not boiling the gauge temp stay in middle
If I put heater on high it take longer for coolant to build up in reserviour
Is the headgasket blown

I did chemical test and it was ok no change in color
I took the thermostat out it opened up when I put it in boiling qater

I took one of the plugs in the back on this duratech engine and under pressure anti freez came out from the plug hole
This confirm its a headgasket or something worse

LEAking coolant front passanger side when engine is off

By engine off, do you mean it leaks after it has been running and is hot? Assuming that is the case, and that you have already checked the hoses, and the cap (If the cap is bad, it will leak out there), try taking the overflow tank out and turning it over. These tanks have a tendency to develope cracks that usually only leak when under pressure.

If the tank looks good, and you have ruled out the cap, I would get the system pressure tested. You may also want to get a compression check. If the head gasket is leaking, coolant may push out the tank after the engine is shut off. If this is the case you would see it coming out the cap, or at least boiling in the tank.

Car smells like antifreeze, I dont see a leak but smell antifreeze, coolant resovoir gets low enogh to add more. Help
head gasket is ok

Water starts leaking from the coolant system seemingly when the car heats up. When I drive it around town it seems to not lose much water, but when going on the freeway things start to happen. The system has been pressure tested and held pressure. Another problem, which I'm guessing has something to do with the faulty coolant system, is the A/C not providing any heat. When I had my car serviced a while ago I could get heat from the A/C system for a while, but it stopped working again and now I only get heat on rare occasions (almost never works, but not entirely out of order since I still get heat sometimes?). Right now I keep filling up the coolant system water a couple of times a week, as needed. There is no water leaking inside the car, which I've heard is a common problem. Could it be a blown head gasket? What more possibilities are there?

No white smoke from the exhaust, and motor oil looks fine. No leak noticed when placing cardboard under the car.

I brought it to another mechanic to have a second opinion, and he as well concluded that there was no leak to be find after performing a pressure test.

Then he showed me that there was a lot of rust on the inside of the coolant container, and told me to keep an eye on the container cap and see if water was leaking form there. So I did, and he was right about that; water had been leaking out around the cap when I checked.

For the heater issue his suggestion was that the rust in the system caused some for of clog. He said that he could flush the system, but that with so much rust some parts (heater core, and a couple more?) Could crack during the flush.

Does this sound like I can exclude a head gasket issue, and is it a logic explanation of the heater issue?

Oh, and I forgot to ask the mechanic about the waterpump weep hole. I guess it has not been checked, if it's not included in the standard procedures.

I had my mechanic flush the coolant system, and it seemed to be effective at first (held pressure), although it did NOT fix the heater issue.

At first it seemed okay, not loosing any water/anti-freeze for a day, but two days later it was low on coolant again, and I also noticed a leak of anti-freeze from underneath the front of the vehicle that wasn't there before.

Oil is now milky and light brown (in the picture it looks white but the flash made it look brighter than it actually is. The oil looked perfectly fine before the flush, and my mechanic had the oil changed while the flush was performed), which I understand is a possible indication that there is a problem with a head gasket afterall. As can be seen on the stick in the picture the oil/water level is VERY high. Do I even dare to drive the car to my auto repair shop when the oil looks like that?

I drove the car a very short distance, but it still seems to run smooth without any problems. How noticable would it be on the car's performance if a head gasket needs to be replaced?

Coolant leaking from front of engine under manifold. Is it a freeze out plug?

My vehicle started smoking then after leaving for 3 days, I saw where the coolant had gone down and vehicle is leaking coolant under neath of vehicle.