P0172 98 Taurus running rich and burping out coolant tank

I have a 98 Taurus wagon that I am getting a P0172 and P0301 on. I pulled spark plug #1 and it was worn badly. The plugs are Autolite plantinums, and are not that old. So I changed plugs and reset the codes. They came back after 30 minutes. I pulled out plug #1 again and this time the plug has a build up and was extremely wet with fuel. Along with that, I am having some coolant issues. I have noticed that if the car sits all night in 10 degree weather,I take off the coolant cap, start the car, I immediately have steam/fog/smoke in the coolant tank and it would also appear, air bubbles are coming up from bottom. This causes the car to release pressure out of the cap every 3 minutes. It also has a strange smell. I am getting the same smell inside the car. It kind of smells like exhaust. I did see underneath the car right under the transaxle that there is some coolant driping. The only thing I can figure is its coming from a soft plug behind the bell housing. I havent looked yet. I have checked compression on all cylinders and 4 are 125, 1 is 139, 1 is 140. All indications point towards a head gasket but I am trying to confirm. Any thoughts?:banghead:

The symptons do seem to diagnoise a head gasket.

the compression check doesn't

have you done the compression check with the engine both hot and cold

I bet it will give different readings

Mike
:smokin:

I have done a compression when engine both hot and cold. When it was hot the compression were as listed in original question. When cold, compression is alot higher. All the cylinders were in the 147-155 psi range and no lower. I was hoping that would diagnose it without question,but still not 100% sure. After draining coolant from system, it had a brownish color and it is not that old.

Are you doing pressure check with all plugs out? Are any green? Are you getting an excessive amount of smoke/vapor and water out of your exhaust pipe? If easy, is your o2 sensor green? Just off the cuff, it sounds like your head has an internal crack. I say that rather than the gasket because of your pressure readings. The Faulty plug/cylinder may mean something more.

I took the compression readings with all the plugs out. When I pulled 02 sensor out of affected bank, it was greenish. I also noticed greenish residue by the holes in the converter. Because all symptoms except compression test pointed to bad gasket, I pulled the heads. I did have a break between cooling jacket and cylinder 1 in the gasket. It was small, but you could definately tell it had been leaking. Plus the inside of the valve covers and the bottom of the intake had milkshake look to it. Maybe if I would have warmed the car up to its maximum temp and let it run a while, the compression readings would have been different. Would have antifreeze leaking directly into the cylinder cause the misfire and the top of piston and valves to carbon up? Could the O2 sensor detected a problem and dumped more fuel into cylinder 1? The rest of bank 1 and bank 2 look ok. I am going to change both head gaskets and see how she does.

Update.....
the bank 1 cylinder head gasket is leaking. It had a leak between #1 and the coolant jacket, which would explain the steam in the coolant tank when I started it cold. I am going to have the heads checked tommorow to make sure they are'nt warped/cracked. For some reason this did not show up on compression tests. The only thing I can figure is I have not really drove it since it started to have issues and it did'nt have a chance to get really bad. The thing that concerns me is the top of the piston and the valves have a buildup on them. Is this from the coolant getting in on the downstroke?