temp sensor problem

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Nov 10, 2000 | 12:25 PM

96eb300

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temp sensor problem

Hello, I have a 96 f150 4.9l 2wd Eddie bauer Truck. About a month ago at 70ish k miles, my check engine light suddenly came on. It was running fine at the time, and I had just replaced my O2 sensor, so I was clueless as to what could be wrong. I had a buddy who is a mechanic. He read my codes for me, (OBD2)and it came back with temp sensor out of range. As far as I know there are only two temp sensors. There is one comming to the dash for the temp needle, and one near the block with a wireing harness on it... I obviously changed the one with the wireing harness. Disconected the battery, hooked it back up and drove the rest of the day. After about 5 hours it came back on with the same code... What gives??? Is there another sensor that I dont know about? The sensor I replaced had a two wire harness on it. It runs fine, and I have not noticed any thing abnormal. In fact I have been driving it daily for about two months since.. but that check engine light is annoying... just wandering if anybody could give me some advice.

Thanks

Nov 10, 2000 | 03:38 PM

hotrodford_88

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From: Texas

temp sensor problem

[font size="1" color="#FF0000"]LAST EDITED ON 10-Nov-00 AT 04:41 PM (EST)[/font][p]If I am not mistaken there are two Temp sensors on most of Fords engines. Which one did you replace? One is called the engine coolant temperature sensor, and the other is just the temperature sensor. If you can tell us which one you replaced it will help us out. And where it was located.

I hope this is of smoe help to you.

1988 F-150 Custom to XLT Lariat conversion, 5.0 EFI (formerly 300 I6), 5-speed M5OD, 3.08 rear gears (will be upgraded to 3.55's), Summit headers, Flowmaster muffler W/ dual 3.5" tips 24" long. Caution Customizing in progress, Watch for flying tools & Parts!

Nov 10, 2000 | 03:46 PM

96eb300

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temp sensor problem

Come to think of it, I remember I had to use teflon tape to keep the new sensor from leaking around the edges... it defenately was a coolent temp sensor. I could not find any other sensor on the truck that had a harness on it... is it buried, or am i just blind??? Guess I should get a repair manual so i could find this stuff huh?

Nov 10, 2000 | 04:08 PM

cgl

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From: NorCal

temp sensor problem

Nov 10, 2000 | 04:37 PM

hotrodford_88

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From: Texas

temp sensor problem

OK, just referred to my trusty (oily) Chilton's manual. On a 300 there should be 2 sensors. One is the engine coolant temperature sensor and the other the other is the coolant temperature sender. The temperature sendin unit is mounted on the passenger's side of the engine just below the head. And the engine coolant temperature sensor is located in Thermostat housing (?) where the upper radiator hose mounts on ( i think) it has been a while since my truck had the 300 in it. So I will have to think backwards. By the way which code # was the computer giving you?

1988 F-150 Custom to XLT Lariat conversion, 5.0 EFI (formerly 300 I6), 5-speed M5OD, 3.08 rear gears (will be upgraded to 3.55's), Summit headers, Flowmaster muffler W/ dual 3.5" tips 24" long. Caution Customizing in progress, Watch for flying tools & Parts!

Nov 10, 2000 | 04:55 PM

96eb300

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temp sensor problem

To be honest with you I really don't remember the code... I only remember the explaination of the code. It is the only old body style year that they used ODBII... Being my luck that just happens to be the year I own... haha. I am going to go out and look right now and see if I can find it. I bought both sensors from the auto parts store. The other sensor doesnt have a harness on it... So I really didnt think that could be my problem sensor, but who knows.. I'll just have to find it and replace it. If i am "lucky" it will be the one that is causing the problem. Just for giggles, does your parts manual have a diagram for it? Does it have a harness? I just figured it must have a harness to send voltage readings to the computer. Never even crossed my mind to try the other one. I'll let you know if i find it.

Nov 10, 2000 | 05:11 PM

96eb300

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temp sensor problem

OK, looked but to no avail. I dug out that part,and looked at the box. Sure enough the box says "temperature sender". I have not put this one one yet. The other sensor was near the front of the heads facing the radiator. Very easy to find... This other sensor is SMALL. the passenger side just happens to be the more cluttered side with both intake and exaust junk weaving around it. I could not make anything out that looks like this, but then again, once this one is screwed in it will only stick out about 1/2 inch. The top side of it has a post that is threaded... It looks like something screws on it.. The only thing I found even close was on one of the exaust manifolds, but it was bigger and had a harness on it... Its harder to see around this engine being fuel injected and all. I used to own a 86 4.9L. MUCH more room in there... Was as about as simple as it got. Is there anymore info you can give me on this? something else next to it that might be readily identifiable perhaps? Thanks again... You have been really helpfull