Temp guage not reading right

[tjsxplodr]

The temp guage is going wacky now....most of the time it won't even register above the C. Could it just be a faulty guage? Or is there something else connected to it that could cause this?

 

[Iron Weasel]

Chances are it's the sending unit and not the gauge. It'll run around $10 - $15 at any parts store and it's fairly easy to replace provided you have the right size wrench since a ratchet & socket don't fit in the area very well.

 

[tjsxplodr]

Ok, yeah, I was thinking maybe it was the sending unit, cuz this doesn't happen all the time. How do I replace the sending unit and where is it located?

 

[Iron Weasel]

Replacement is easy. Find a combination wrench that fits the sensor (thinking 3/4 or 13/16, but don't quote me on it), unplug the electrical harness, remove the sensor, install new sensor, plug harness back in, done.

Here it is on my 94, should be the same on a 91. First picture is from the drivers side, you can see the A/C compressor and air intake labeled for reference. Second picture is from the passenger side and you can see the sensor itself more clearly.

 

[tjsxplodr]

Ah ok, I know where that's at. Just gotta find the right sensor now. Thanks!

 

[BWTGUY]

Umm Iron Weasel isn't the sensor you marked "coolant temperature sensor" the one that feeds info to the PCM? I believe the other sensor to the left side of the air intake as you face the rear of the EX is the one that needs replacement. It is the one that feeds the temperature gauge vice the PCM. I'm doing mine this weekend so can let you know then.

 

[Iron Weasel]

Umm Iron Weasel isn't the sensor you marked "coolant temperature sensor" the one that feeds info to the PCM? I believe the other sensor to the left side of the air intake as you face the rear of the EX is the one that needs replacement. It is the one that feeds the temperature gauge vice the PCM. I'm doing mine this weekend so can let you know then.

Yeah, sorry. I should've specified. I posted both pictures from a previous thread.

If you're standing directly in front of the truck looking at the throttle body then the one you're after is the sensor that has single wire (Red / white tracer) harness. It's going to be the one in the second picture.

Just for confusion sake, both sensors are "Engine Coolant Temperature Sensor" but there are different part numbers depending on if it's the one for the gauge or the one for the PCM. The one for the gauge is cheaper whereas the one for the PCM is about twice (if not more) the cost.

 

[tjsxplodr]

Ok I think I found the one you're now talking about. Now to find the correct sensor lol. Any good sites I should search? Anyone know the part # for this sensor?

 

[tjsxplodr]

Ok I took off my air intake tube, and have a couple views of the area. Which one is the one I need?

 

[Iron Weasel]

Check Autozone and do a search for SU201. It's like $15 or something last I looked.

 

[tjsxplodr]

OOPS, I found it lol. Now which one is the one I have to replace, is it the one that is to the right of the metal tube and under the throttle body that's in my pic?

 

[Iron Weasel]

http://www.autozone.com/autozone/pa...hByPartNumber=true&itemIdentifier=147389_0_0_

That's the one in your picture you just posted that's just below and to the left of the throttle body.

 

[tjsxplodr]

Got it, thanks! I cleaned the electrical connections on mine, and will see if that fixes it, if not, then I'll buy a new one thanks again!

 

[burgundy1994xlt]

Yeah, sorry. I should've specified. I posted both pictures from a previous thread.

If you're standing directly in front of the truck looking at the throttle body then the one you're after is the sensor that has single wire (Red / white tracer) harness. It's going to be the one in the second picture.

Just for confusion sake, both sensors are "Engine Coolant Temperature Sensor" but there are different part numbers depending on if it's the one for the gauge or the one for the PCM. The one for the gauge is cheaper whereas the one for the PCM is about twice (if not more) the cost.

I thought the one on the left is called the sender, the right, the sensor.

 

[tjsxplodr]

I have no idea lol. I'm just going by what these guys are saying. I haven't looked that up yet haha.

 

[surf]

The sending unit that goes to the guage only has only a sine wire going to it and should ony cost 7-8 bucks.

 

[tjsxplodr]

OOOOK. That is the one I'm after. My temp guage is not reading right most of the time. Its usually at the low end of normal, but then it stays at the C alot of the time. My cooling system is full of coolant, and I don't have a head gasket leak that I know of. So which one is the sending unit, that small one directly across from the sensor?

 

[surf]

Yes.

 

[tjsxplodr]

Ok, thanks!

 

[tjsxplodr]

Ok, so new symptoms, fan stays running all the time, the hoses are hotter than **** and the gauge is at below C forever now....