engine temp help!

[fisherbear]

I have a 1994 Mazda b3000... basically a v6 ranger.... I am used to the temp gauge being around 30%... I live in Houston and it's hot... a few days ago on the way home from a training the temp went above the half way mark to around 70% which freaked me out... It was still in the normal range but way above what I'm used to seeing... I'm a teacher and I NEED a dependable ride... I bought a new thermostat but one of the bolts is rounded out and I can't remove it... I don't want to break the head off the bolt and cause a bigger head ache.... I replaced the coolant sensor as it broke in half... I replaced the coolant and drove it around for 30 mins... no overheating but it's right at 50% on temp gauge... my question is where is the temp gauge normally on your v6 ranger or b3000? I'm trying to figure out how concerned I should be... thanks, Johnny

 

[Rearanger]

50% sounds about right. If you've got access to a laser temp gun you can point it just at the stat location to see actual temp for better idea.

 

[bucko]

Some say the temp guage simply registers half way all the time, but I disagree with this. My temp sensor in my 2000 3.0 (there are two; one ror the guage cluster, and one for the ECU) was bad; it never went past the half way mark, even when the coolant got hot, very hot one weekend during an e-fan install. After replacing it, the guage will now fluxuate between 40 to 50% reading on the guage. To test it, unplug the two prong wire harness from the guage (don't panic when you only see one wire in the harness, this sensor is the guage cluster). With the key to "on" (but engine NOT started), ground this wire. The guage will be pegged, all the way to hot. Remove the ground, and the guage will be all the way to cold. This proves the wiring and guage itself are good; replace the sensor.

In you case, how long has it been since the radiator/coolant system has been flushed/cleaned? You may have a radiator that has a row (or two) of plugged tubes, lowering your coolant effectiveness.

And thanks for serving. Much appretiated!

 

[JP02XLT]

These trucks are well known to collect dust between the radiator & condenser, this will cause higher than normal temps as well, would be a good idea to take a look and flush it out with some simple green etc and the garden hose.

As for the gauge, mine stays about 1/2 way for normal almost all the time, you might see it a little above half on 100+ degree days.

JP02XLT

 

[fisherbear]

I changed the fan clutch and the temp is back to about 30%

 

[Rearanger]

the temp is back to about 30%

Yes, but do you know what temp the coolant is running at? What temp stat did you install - if you installed one? Previous owner may have installed cooler than factory stat.

 

[JP02XLT]

The gauge is really just a rough indicator that the engine has temperature in it, nothing that is going to tell you that 30% is xxx degrees.

JP02XLT

 

[Rearanger]

The gauge is really just a rough indicator that the engine has temperature in it, nothing that is going to tell you that 30% is xxx degrees.

There is a relationship between gauge position and temp, it's just that the gauge does not have graduations. Sender/sensor design would determine temp and gauge position. I'm betting hot gauge position pretty much equals factory stat spec.

 

[JP02XLT]

Yeah your correct, I have a Scan gauge on mine, the factory temp gauge starts to move at about 120 degrees on the scan gauge, with the scan gauge reading 185-190 the factory gauge is reading just a tad above 1/2.

JP02XLT

 

[adsm08]

The factory gauge is an idiot light. It goes to a set position for "normal" operating temps.

 

[Rearanger]

The factory gauge is an idiot light. It goes to a set position for "normal" operating temps.

Wouldn't that "set position" be the normal temp. If below or above not normal? Only difference I see is more accurate graduated gauge with corresponding sensor. 195* on factory gauge could be "set" position.