Dave H M
IL
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I keep reading posts about the temperature guage in my ford psd being an "idiot guage" and doesn't show real temperature.
I don't understand, it shows cold and gradually climbs up to operting temp as the motor warms up.
Can someone explain this "idiot guage" reference to me?
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Polishnurse
Schodack, NY
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There so simple even a Caveman Can Read them.
Actually I think there referring to the light, that tell you that car is now running so hot that what you see around you is steam. There not in reference to the graduated Gage. Just my two cents. Bill
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usmohls2@yahoo.com
CA
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Buy the time the idiot light comes on you have blown a head gasket.
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Yahooligan
Temecula, CA
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huh, first I've heard of an idiot gauge for coolant temp. Idiot gauges for oil pressure have been in place forever and still are today, the gauge does nothing more than show you there's at least 10psi to trigger the oil pressure switch.
If your oil pressure gauge never moves once started, regardless of engine temp or RPM, then it's an idiot gauge. Oil pressure will fluctuate depending on engine RPM and oil temp, cold(er) oil having a higher pressure off-idle (And sometimes at idle) than oil at operating temp.
My Dodge had and my Titan has a true oil pressure gauge, my '97 Ford had an idiot gauge for oil pressure. They all have/had actual gauges for coolant.
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Hogan & Clan
2005 Nissan Titan CC SE 4x4
2010 Keystone Hideout 31BHSWE
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h2guy
Ain't seen a sign yet!
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As far as a Ford goes, both oil press & water temp, are idiot gauges. On my '01, temp starts at 0, then will gradually go up as engine warms up, till mid-range, and stays there, period. Even when the fan clutch comes on and screams all the way up the "hill" till it cools everything back down, it'll still read mid-range, "Everything is okey-dokey, I was just checking the fan clutch for you". An idiot gauge.
Oil press gauge will start at 0, and as soon as engine has fired and completed maybe 10 revs, it jumps to mid-range and never varies. Then the illuminated little oil can pic next to the speedometer will remain lit for about 4 ore secs and it'll go out, never to be seen again till next start up.
The water temp gauge "idiot" style was deemed necessary because so many diesel newbies were running to their mechanics about their "overheating" problems. Diesel engines water temps vary wildly when operating so to give "Joe Blow" a warm fuzzy this style of coolant temp gauge was developed.
Rick & Carolyn
01 Ford SC 4x4 DRW
01 CarriLite 5ver
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thomasmnile
Deltona, Fl.
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Dave H M wrote:I keep reading posts about the temperature guage in my ford psd being an "idiot guage" and doesn't show real temperature.
I don't understand, it shows cold and gradually climbs up to operting temp as the motor warms up.
Can someone explain this "idiot guage" reference to me?
Yes, like idiot lights, they are connected to an electrical sensor that reads water temp or oil pressure; instead of an idiot light illuminating, the electrical impulse from the sensor goes to the gauge and causes the needle to move on the gauge to display pressure or temperature. Are they as accurate as "mechanical" gauges? I dunno. Aftermarket mechanical gauges are around; Stewart Warner, AutoMeter, ISSPRO, all offer them, though most aftermarket gauges sold are electro-mechanical. I had a mechanical transmission temperature gauge installed on my Ram.
Mechanical Gauge, you ask? For oil pressure as an example, a fitting is placed in the engine's oil "circuit" with a capillary tube essentially providing a direct connection from the engine to the gauge. They do a good job unless that tube breaks, since engine oil is running right up to the gauge. Temperature gauge setup involves a bulb sensor screwed into the block with an attached tube connected to the gauge. No coolant traveling through the tube; the coolant heat detected by the bulb sensor is conducted through the tubing and reacts with a bi-metal (I think) movement in the gauge assembly, causing the needle to move across the gauge face.
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Yahooligan
Temecula, CA
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thomasmnile wrote:Dave H M wrote:I keep reading posts about the temperature guage in my ford psd being an "idiot guage" and doesn't show real temperature.
I don't understand, it shows cold and gradually climbs up to operting temp as the motor warms up.
Can someone explain this "idiot guage" reference to me?
Yes, like idiot lights, they are connected to an electrical sensor that reads water temp or oil pressure; instead of an idiot light illuminating, the electrical impulse from the sensor goes to the gauge and causes the needle to move on the gauge to display pressure or temperature. Are they as accurate as "mechanical" gauges? I dunno. Aftermarket mechanical gauges are around; Stewart Warner, AutoMeter, ISSPRO, all offer them, though most aftermarket gauges sold are electro-mechanical. I had a mechanical transmission temperature gauge installed on my Ram.
Mechanical Gauge, you ask? For oil pressure as an example, a fitting is placed in the engine's oil "circuit" with a capillary tube essentially providing a direct connection from the engine to the gauge. They do a good job unless that tube breaks, since engine oil is running right up to the gauge. Temperature gauge setup involves a bulb sensor screwed into the block with an attached tube connected to the gauge. No coolant traveling through the tube; the coolant heat detected by the bulb sensor is conducted through the tubing and reacts with a bi-metal (I think) movement in the gauge assembly, causing the needle to move across the gauge face.
Not to be a stickler for details, but gauges with electronic sensors aren't "idiot gauges" they're simply electronic gauges.
An idiot gauge is one that simply connects to an on/off switch to give the false sense that everything is "OK" when in fact the only parameter met is the minimum spec to trigger the switch.
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smkettner
Southern California
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People call them idiot gauges because there is no movement in the normal zone. This keeps the idiots out of the dealership thinking something is wrong when the gauge moves up a bit on a hot day. I understand it will actually move higher when above normal as determined by Ford. Many people would like to see it move sooner. I am just fine with it.
Read more here
* This post was
edited 11/03/09 09:10pm by smkettner *
2001 F150 SuperCrew
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firecapt1
Sonoma County, CA
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I dont' think there is any such thing as and "idiot gauge."
Consider the difference between a "gauge" and a "light." The gauge moves along a scale based on pressure or temperature, whether it shows you an exact reading (in degrees, psi, etc.) or just a general scale, it gives you a reasonable idea of what is happening with that particular system (oil, water, transmission,etc.).
A light (idiot light) comes on when things have gotten so out of control, that the system it is monitoring is way beyond it's safe limits. Often, pulling to the side of the road, stopping, and turning off your engine at that point is too late, you have already done damage. I don't need to know, for instance, what my exact transmission temperature is, just if it is rising above normal and when it approaches critical levels.
As per my signature, I have a 2007 Ford F-250 SD Diesel. It has a factory built in boost, water temp, transmission temp, and oil pressure gauge. I believe that they are all adequate to allow me to anticipate problems and react in time to avoid damage.
That being said I would like to have an Exhaust Gas temp gauge and I may add one someday. In the end, gauges, whether factory installed or after-market are far superior to "idiot lights."
Frank, Martha & Ryan
2007 Ford F-250 SD Crew Cab
2006 Cougar 289EFS
Happy Trails to you, until we meet again!
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Yahooligan
Temecula, CA
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One more thing to add is that even electronic gauges with an "L" and "H" or "C" and "H" with a normal range in between are indeed better than idiot lights or gauges in that they give you an idea of how quickly things are changing or going wrong but they don't give you actual numbers.
My coolant, oil pressure and trans temp gauges are all ranges without numbers but aren't idiot gauges. The ultimate question has always been "What are the high and low limits of the normal range?" To deal with this and know exactly where things are at, especially trans temp, I installed a Bully Dog GT Tuner. Now I know without a doubt how hot my trans gets and this helps me know how often or soon I need to have the fluid replaced.
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