Temp Running Hotter than Normal?


gungfudan

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I have a 94 Mazda B3000. I changed everything out in the cooling system last year in December except the temp sensor. I installed an all aluminum radiator and an electric fan.
The electric fan I had on a temp switch but had to run it straight so it would come on and run all the time when the vehicle is running. I also just installed yesterday another radiator because the all aluminum one I bought was leaking after a month. I thought the fan running all the time would keep it running cooler but I guess not. So I reinstalled the clutch fan an hour ago.
The clutch fan used to keep it down to the C mark or the mark above it never passed that. Now it is running midways or 1/3 of the way. I have probably flushed the radiator a dozen times since I have gotten this vehicle last year. There is only 58,000 miles on this truck. I don’t know if the sensor is going bad or the aluminum radiator makes it run hotter but from my understanding it is supposed to run cooler.
Any ideas of what could be going on.
 
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gungfudan

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Guess I will change the temp sensor to see if that makes a difference.
 

cbxer55

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No replies. Interesting. Mine is a 98 that has never had major surgery, 162,000 miles. Changed the coolant twice in 19 years. Run a 180 thermostat. Keeps the needle noticeably lower than where it ran with a 195. Ran the 180 since 2004. Never a code for the computer unable to make the switch from open loop to closed due to inadequate temperature.

My 04 Lightning is supposed to have a 180 stock. Run a 170 in it for the last five years. No problemo.
 

McCormack

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If replacing the temp sensor didn't fix the problem, then elevated engine temperatures are a sign of a cracked head or blown head gasket, which is a common problem with the Vulcan V6.
 

cbxer55

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Really? And somehow mine is 21 years old and has 162,000+ miles without that happening? Wow! I must be lucky! Maybe putting in that 180 T-stat helped?
 

Bird76Mojo

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I don't believe cracked heads or blown head gaskets are all that common with the 3.0 V6
 

RonD

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Ford temp gauge has 210deg as 1/2 way point

In the late 1970's SAE(society of automotive engineers) concluded a study for the best long term coolant temp in a gasoline engine
190-200deg was determined to be best temp for coolant.
This temp keeps the engine at best MPG temp(efficiency) and the oil gets hot enough to burn off contaminants
It's just science, take it or leave it

Prior to that 180deg thermostats were standard, in late 70's early 80's Ford started using 190-195deg thermostats based on that study

So normal temp gauge reading after warm up should be just below 1/2, if pulling a load or climbing a long grade it may go above 1/2 way, 230degF, which is fine
Over heating is above 260degF, above 3/4 on Ford gauge

The thermostat is what sets MINIMUM coolant temp, in this case 190degF, just below 1/2 on the gauge
Radiator is only there to remove EXCESS HEAT.
In the case of the 2.3l Lima engine, radiator may not even get warm in winter months, lol, these engine just have big cooling volume in the block and heads and just don't generate alot of EXCESS HEAT

The Fan Clutch unit has the bi-metal spring on the front, this spring expands when heated up and that closes a valve inside the clutch causing it to engage more, which causes fan blades to spin closer to water pump RPMs
This system works well IF center of radiator is getting warmed up by coolant, blocked passages can prevent that,
Also fan shroud must be used so spring only gets warm air thru rad

Electric fans are good because they only use engine power when needed, not all the time like mechanical fan does

As far as cooling radiator one is not better than another assuming they are both moving the same amount of air when in use
Lower rad hose is best, IMO, for temp sensor when using an E-fan
When driving, the air flowing thru the grill/radiator usually will give enough cooling without the fan on
Most radiators provide 15deg of cooling without fan, 25 deg with fan




Engine cooling system can be "plumbed" in a few ways
Most Rangers used upper rad hose thermostat and lower rad hose return to water pump
Since the thermostat is not open during warm up there needs to be a by-pass that replaces flow in and out of radiator until thermostat does open
That usually the Heater hoses.
Heater hose closest to thermostat is the OUT to heater
Heater hose on water pump(or lower hose) is the IN from heater

Water pump send coolant into the block, and up through the heads to the thermostat, if its closed then all coolant flows out the heater heater hose thru the heater core(or bypass valve) and then back to water pump, to make another trip around

With just the heater hoses passing coolant there is less flow thru the system, this allows engine to heat up faster which is good.
Thermostats are rated at +/- 2deg usually, so at say 189degF it will start to open and a little coolant will start to flow to radiator
The cold coolant in radiator will circulate and cause thermostat to close again, then it will heat up again and open a bit more, this opening and closing will continue until there is a balance at close to 190degF coolant temp in upper engine

Thermostats don't open fully until temp is 15-20deg higher than rated temp
 

McCormack

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I don't believe cracked heads or blown head gaskets are all that common with the 3.0 V6
You believe wrong. The Ranger forums are rife with owners such as myself that have dealt with cracked heads/blown head gaskets on their 3.0's.
 


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