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Discussion Starter #1
I did search but I couldn't really find the answer - I don't think this is normal behavior.

My temp gauge always reads very low, just off the blue stripe (it does move, just not much), no where near the middle of the gauge. Does this indicate a different thermostat has been installed in my vehicle? I'm getting ~22mpg 50/50 city highway, so I am wondering if this isn't contributing.
 

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I wouldn't trust the temperature gauge for checking anything. Get an external temperature meter of some sort.....a simple cooking thermometer will do. Put it in the coolant over-flow tank, and warm up the car for a while (you can leave the cap open).

Depending on what kind of thermostat you have, the temperature should be around 180-220 degrees. If your engine is really running cool all the time, your MPGs will go down.
 

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C2H5OH
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With a 180* thermostat your gauge will still be almost straight up, just to the left maybe a needle width.
If your gauge is staying that low I'd have to say the Cylinder Head Temp Sensor is shot and not feeding the ECU the proper resistance.
 

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i have a 180 t-stat and i run about 190 and 205 under heavy driving
 

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Discussion Starter #6 (Edited)
I see people reporting actual numbers - is there a way to check this? Edit: hurpdurp, cooking thermometer it is.

Cylinder Head Temp Sensor eh? I'm guessing that this is what the ECU tunes to, and the thermostat merely controls the cooling system. This would make lower mileage due to running rich likely also, no? Thanks for the help! +rep
 

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FF's Night Security
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If you do the odometer trick one of the displays actual temp in F and C. Has for an after market gauge. I have an autometer and I between 160 all the way to almost 230 which is really close to over heating and warping the cyl head. My fans don't come on unless it gets hot about 230. I did replace the resister and assciated harnes or pigtail whatever you want to call it. Mainly though I run right aroung 180 and up to 210 once I get on the highway or road with a fairly good speed limit it'll drop to 160-180 always. I come to a stop it'll creep up to 210 and somtimes past it but will drop has soon has I start moving. I don't trust my factory temp gauge at all it's almost never the same has the after market gauge.
 

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You likely need a new CHT sensor. However, I'd check to see if you have a stuck thermostat first. Thermostats can stick open or closed. Yours is likely to be stuck open from your conditions. Like Bluefront wrote, MPG will drop tremendously when engine temps are low. Combine that with an old fuel filter, bad gas, and other typical MPG robbers, and you're getting 22 instead of 32.

The first thing to do would be replace the thermostat. My reasoning is that it's cheaper- about $10 to replace the thermostat and gasket, and that might fix the CHT sensor as well. I have no idea what a CHT costs, but if you still can't get the gauge to work, I'd definitely contact Mike at Hilbish Ford and get a new part. The car won't blow up without it, so there's no sense in paying to get one sooner than Mike can ship it. After replacing the thermostat, warm the car up, and check engine temps as Sleepyboy suggested using the odometer. If you need a How-To on that, go to our home page and click the "Member's How-To Archive". There should also be a How-To in the Complete How-To Archive stickied to the top of this forum.

If you get the gauge to come up, and things seem to be working better- I'd consider going through the typical MPG robbers starting with the cheapest- like the fuel filter, air filter, and ending with the O2 sensor if the others don't increase fuel economy sufficiently. As a general rule, I try the cheapest repairs first in these situations where I can't pinpoint a single cause through diagnosis.
 

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FF's Night Security
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The factory sensor is accurate unless its hooked up to the factory gauge lol. Do the odo trick and you will see if what temps its really putting out and that will tell you if your sensor is bad. It also displays in both C and F degrees. Is'nt the CHT in a hard to reach spot? I do belive its under intake manifold on the pulley side of things
 
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