Grrr!!!!!

My check engine light came on for th first time this morning and it is the worst feeling I've ever had in relation to my truck. 70,000 miles and it's been running great.

So what happened????

I left work at 6:30am this morning and got on the highway. My truck felt like it was running a little rough,vibrating. I thought that it may just be the muffler shaking so I step on the gas to drop out of overdrive and bring the RPM's up but it still feels the same. Then I wonder if my tires are out of balance again and decide to just slow down to 55-60MPH. After 10 miles of interstate I get off on a Co Rd with a 45mph speed limit and plenty of stop lights. Because my truck doesn't seem happy, I take it easy but the there's a dump truck in front of me going way too slow so I step on the gas to go around him. The RPM's go to 3000 and the "CHECK ENGINE" light comes on. My heart starts to race and I'm thinking what the heck did I do??? Should I pull over and look??? I'm wondering of a spark plug wire is loose but the engine isn't missing so I think it must be something else. I had to drive another 5 miles to get home so I took it real easy and nothing happend with the engine. No surging or odd noises.

I pulled into my driveway and when I opened the hood I though the engine sounded a little louder than usual. I put my had on top of the engine and it is HOT!!! Too hot to keep my hand on it. Usually my engine just feels warm so I knew there was a problem. The temp guage stayed normal and and the cooling system seemed to be working fine. Coolant was flowing through the system and I just changed it a few months ago.

I was going to take it to the dealer but I know that they'll charge me for the scan as well as parts and hours of labor and I'm not about to turn my check book over to them.

I went in the house and made a cup of coffee and grabbed my Haynes and Chilton's manuals and went to work. My concentration was focused on sensors telling the computer that the engine was cold and giving it a rich fuel mixture. This would explain why the head was so hot.

I considered the 02 sensors but wasn't about to go out and spend a couple hundred dollars to replace all 4. The engine had all of it's power so I didn't think that is was and air sensor on the intake side. Then I come across the "Engine Coolant Temp Sensor" or "ECT". It sits on top of the engine block and as coolant flows accross it tells the computer how warn the engine is so it can adjust the mixture.

I went out to my truck, looked for it, gave up and went back inside 3 times before I gained the courage to start pulling things of the enigine to gain access. I pulled of the intake tube and a few tubes and wires and used a long screw driver to disconnect the electrical connection from the sensor. I need a 3/4" socket with a long neck as well as a flexible extention to get a hold of the sensor but did manage to get it out.

Couldn't do a traditional cuircit test because my voltmeter is broken so I called a Ford parts dept and it turns out I pulled the wrong ECT.One goes to the computer and the other to the guage on the dash. I pulled the one for the dash. I checked the price while I had him on the line and for the pair I'll only have to put out about $35.00 so I have him order me 1 of each and went back to find the other ECT.

For referrance, the insterment guage ECT is on the top front of the engine block and the computer ECT is on the right front side at a 45 degree angle. I pulled the other and called the parts dept back to verify the part # and this time I had the right one and they'd be there in a few hours.

On the way to the dealer I picked up some teflon tape to make sure I did the job right. Got home with the 2 new sensors and put 'em in there. I didn't reset the computer yet because I wanted to make sure that everything ran before clearing the error codes just in case.

Put all my tools away, cleaned up the coolant, refilled the overflow tank and started the engine. Everything sounded normal and I let it idle for about 5 minutes while I made sure the temp guage was working. Drove around the neighborhood for about 15 minutes and everything ran fine and felt as it used to so I went home and unplugged the battery to reset the computer.

Before I drove to work tonight I debated heavily whether or not I wanted to drive my truck or take another car to but decided I'd give it a shot and see what happened. I drove the 14-15 miles to work without incident and the engine felt just as it did a few days ago, perfectly smooth and powerful. I pulled into the lot and opened up the hood and put my hand on the cylinder head and it was oh so nice and warm, but definately not hot

Problem solved???? Sure hope so. We'll see in a few days.

Important side note/benifit: I've had a slow coolant leak for the past 40,000 miles. I always had a small pool of collant under the engine after a drove it. Never had oil in the coolant or coolant in the oil but could see it drip from the bottom of the engine block onto the ground. Just couldn't find the leak. Well, today I found the leak!!!!The sensor for the temp guage was not sealing tight so very small amounts of coolant would seep out under presure when the engine was warm. With the teflon tape wrapped around the tread it keeps the coolant from coming out. My truck has been sitting out side work for 4 hours now and there is no puddle. Not a drip.

I know there are a few people here that are running rich. Maybe this will help.