Alright, I know you have heard this story before but I would PLEASE like some help diagnosing this problem. First a little Background info about my F150
1997 F150 4.6L V8, Windsor, XL Extended Cab, 4x4, offroad package
145,000 Miles Great Shape other than the freakin' motor!
ALL regular maintanence, oil changed every 3k(may have slipped to 5k once! but atleast I am honest) Not one problem other than general mainenance ever with the truck. I bought it with 103,000 miles and have put 42,000 on it.
Since I have had the truck it has never overheated(not even slightly), never been low on oil, never been low on coolant, never leaked a drop.
PROBLEM:
Earlier this summer I noticed a slight smell of antifreeze while doing some gen. maintenance under the hood but did not think much of it. While doing an extended drive I noticed some coolant dripping on the passenger side towards the back of the engine compartment. At the same time I noticed the truck running rough and thought that it was probably two different problems. I had a few more hours to drive so I decided to limp home with my coolant leak, the gauges were rock solid no heating. Then to my surprise white steam that smelled like Antifreeze started seeping from the air vents in the cab!!
The next morning I took it to a reputable shop with an experienced ford mechanic. Here is his report:
1)computer tested for codes and found P0156 Oxygen sensor circuit fault
2)P0401 EGR Insuf Flow
3)P0303 Cylinder 3 misfire.
4)KOER P1288 Cylinder head temp sensor
5)P1127 Oxygen sensor
6)P1408 EGR flow
Cylinder 3 spark plug is burnt from coolant.

I have noticed no smoke from the tail pipes, and only a small coolant leak on the passenger side in the back of the engine compartment. I believe that most of the coolant in the combustion chamber was being burnt until the plug burnt. I drained the coolant and began dismantling the top of the engine. The coolant was darker than normal and had a weird odor.
I am hoping that it is the intake manifold gasket, but probably the head gasket. Are my assumptions correct???
Thanks for your time
JasonT

 

Welcome to the forums.
It sounds as though you have a leaking head gasket, as well as some other more moinor issues. Most of these problems are very common to our trucks.
Try using the search function above with the advanced feature. Just type in the code and you will see many threads with the same OBD2 codes. G luck

 

If you replace the head gaskets I would also replace the 4 freeze plugs under the front timing cover. i had one leak at 90K miles and fill the oil pan but not a drop outside. They are only about 1.50 each but it cost me ~950 yo replace them.

 

It would suspect that the head gasket leak allowed combustion gasses into the cooland passages. This may have blow a hole in the heater core. Have it pressure tested. Find a reputable shop than can finish the head surface to the required Ford tollerances. Have them check the head and block for warping. If the head needs to be milled and it is not done to Ford specks it can casue the Multi Layered Metal head gasket to deform casuing another leak.

JMC

 

Does coolant smoke from vents always mean that you have a busted heater core. Could it be from the bad head gasket and the coolant being burned in the combustion chamber or do I have two problems here.
Thanks for everyones help!!