sensor search
#1
sensor search
My 2000 Expedition with a 4.6 decided to not start right up since cold weather
arrived finally the other day. It only does this when it is cold out and it has set
for awhile and the engine cools off in warm weather 50 or above it will not do this. It reminds me of a temperature sensor which I was going to try since it
was fairly cheap, the engine starts after a couple of rotations but then it falls down in rpms then when you bump the throttle it comes up and stays. Anyway
I have looked all over this 4.6 and I cannot find the location of this water temp sensor. I called the local Zone to see if they had any idea and they said their book showed up front on the left side of the engine but I can't see it there at all, I just hope it isn't under the intake or something crazy like that. I just installed a new battery when it first happened since mine was 5 years old, so it shouldn't be the battery more than likely. It just acts like a carb engine that doesn't have the choke set correctly, and isn't getting enough fuel at first. Any ideas or help is appreciated.
AD
arrived finally the other day. It only does this when it is cold out and it has set
for awhile and the engine cools off in warm weather 50 or above it will not do this. It reminds me of a temperature sensor which I was going to try since it
was fairly cheap, the engine starts after a couple of rotations but then it falls down in rpms then when you bump the throttle it comes up and stays. Anyway
I have looked all over this 4.6 and I cannot find the location of this water temp sensor. I called the local Zone to see if they had any idea and they said their book showed up front on the left side of the engine but I can't see it there at all, I just hope it isn't under the intake or something crazy like that. I just installed a new battery when it first happened since mine was 5 years old, so it shouldn't be the battery more than likely. It just acts like a carb engine that doesn't have the choke set correctly, and isn't getting enough fuel at first. Any ideas or help is appreciated.
AD
#2
#4
Originally Posted by LxMan1
Sounds more like a bad IAC (Idle air control valve) to me.
Any 4.6L's I've ever seen (none past '97 that is) has the temp sensor in the front coolant crossover in the plastic intake (I've heard this crossover is aluminum on later 4.6L's).
I think my '96 and '97 has two right there in front, one's for the gauge, the other is the computer sensor.
#5
Thanks,
guys I will check that out. I had already looked at the intake coolant passage on the front of the motor it has a brass plug there, I know this is factory because I bought it new. I did find out on one article I read that after 2000 they went from a sensor for the temp guage and one for the computer to one that did both functions. I just can't find it, I even talked to a guy I know that is a Ford shop forman at the local dealer and he didn't know where it was either he just said it might use a cylinder head temperature sensor I bought one of those but I can' t find it at all to swap it out. I will check out the IAC thanks a bunch.
AD
guys I will check that out. I had already looked at the intake coolant passage on the front of the motor it has a brass plug there, I know this is factory because I bought it new. I did find out on one article I read that after 2000 they went from a sensor for the temp guage and one for the computer to one that did both functions. I just can't find it, I even talked to a guy I know that is a Ford shop forman at the local dealer and he didn't know where it was either he just said it might use a cylinder head temperature sensor I bought one of those but I can' t find it at all to swap it out. I will check out the IAC thanks a bunch.
AD
#6
the 99 and 2000 4.6l engines uses only one sensor, a cylinder head temp sensor, it is located on the left head behind the thermostat housing..It is under the intake manifold. You must remove the alternator to see it...Fords manuel says you must remove the intake. I just replaced one on my truck ...It can be replaced without removing the manifold, you have to make your own tool modification....
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