low temp gauge on 93 explorer

[sterlingvw]

few weeks ago i picked up a free dark green 1993 explorer sport 4.0Lv6/auto 4x4- auto everything, loaded except sunroof and roof rack,,.. has 40k/140k/240k miles???? who knows... passed smog. super clean. he had to smog twice it was soo clean. no joke. ford records showed 40k miles and 3 owners so I don't know. he had to make sure on smog and miles.

wonder why it was free?? the temp gauge issue and no dash lights...smacked dash few times and lights all work...all I know. estate sale knew nothing but couldn't sell at auction.

here's what I know tho..

temp at ide is at the first line, driving temp is at bottom of gauge. outside temps 40-60f

put a temp gun on system after 40 mile drive, 140-160 deg with 50-55 deg air temp.

on 10% grade for 5 miles gauges comes to N/O on gauge with just me and no cargo. goes back down in mile on flater ground. 40 degree outside temps that day

heater works good. no water noises in system. no water loss, no water in oil. runs great. clutch fan appears to work.

ive put 3k miles on exploder already and not a issue. any ideas???

 

[arco777]

Welcome to the forum!

I'm not sure what the problem you're having is exactly. Does it appear to be running cooler than you expect? Sometimes people swap in lower temperature thermostats than stock, which isn't ideal and can throw off the PCM. A stock replacement is best.

You could always test the sensor with a resistance check using a multimeter. Keep in mind there is a sender and a sensor, one is for the gauge and the other is for the PCM.

 

[sterlingvw]

so the gauge is supposed to sit at very bottom? it only moves a cm or two. only comes to between n and o (NORMAL) only on one hill.

 

[arco777]

If you're only taking very short drives it may not have time to warm up completely.

Typically my Explorers will warm up to operating temperature after about 5-10 minutes of driving, depending on outside temperature. They usually fluctuate somewhat between O and M. Sometimes I can see the temp rise to the M and as the thermostat opens it drops quickly back to the O.

If the engine was truly running colder than it should, culprits to look at would be a malfunctioning/stuck fan clutch that keeps the fan always engaged, or a thermostat that is made to open at the wrong temperature (not stock replacement). Sometimes backwoods or elderly folks will even remove the thermostat entirely, which is actually a bad idea.

 

[mr cribb]

It COULD be as simple as the temp sender for the gauge (sender with one wire) near the thermostat. It is somewhere between 6-10 dollars for the part.

I gave up on my factory gauge last year trying to track down my over heating issue. I installed a real temp gauge with numbers, it was a cheap one from O'reilly Auto Parts for 23 dollars. I don't drive far in mine anymore 4 miles a day round trip. If I let mine warm up for 15 minutes my gauge will read about 190 (that is the factory thermostat spec) if I don't let it warm up my truck doesn't get above 160.

160 is about the N/O position, 190 is about the R/M position.

 

[sterlingvw]

thanks for the heads up. looks like could be few things, fun fun. ill have to wait till wifes car is done to tear into the exploder. on side note....what bulb goes into third brake light? got warning today to fix it and no bulb installed so im clueless.

 

[Jason94sport]

It COULD be as simple as the temp sender for the gauge (sender with one wire) near the thermostat. It is somewhere between 6-10 dollars for the part.

It's almost always that. Common.