Phony factory temp gauge

[Cobraguy]

I'm not sure if this has ever been addressed, but I stumbled onto this when I had a guy on his high end BMW tell me about his gauge. I checked it out with ours, and sure enough...the same strategy.

It seems that Ford doesn't want us to really know (or worry) about a large range of engine temps. We all know that the oil pressure "gauge" is really nothing more than an idiot light. Well, let me tell you what they do with the temp gauge.

It indeed reads a varying voltage from the sender. However, the strategy employed in the gauge is set so that there is a high range of temps that will hardly move the gauge at all. On mine, at about 185 degrees, the gauge is pretty well in the normal area. But here is where it gets interesting. I ran my temp to 208 degrees, the you could hardly tell the gauge moved at all! I don't know how high it would have to go before the needle would start shooting up to a high temp...but I've heard it can be 220 degrees or more. What Ford figures, is that wide range of temps is 'normal' in their eyes...therefore they show it as 'normal' on the gauge. Only when it gets to a dangerous level will the gauge start going where it belongs.

This is fine for the everyday lay individual who could care less about the status and performance of his engine. As long as Ford thinks it's fine, they think it's fine. But for those of us who REALLY want to know what's going on, this is unacceptable. So I would put a good temp gauge on my "to do" list right along with the oil pressure gauge.

 

[colintrax]

Are you gonna fix the factory gauge or add an aux one?

 

[Cobraguy]

I don't know what would be involved in fixing the factory unit. I went ahead and installed an Aeroforce gauge.

 

[BrianDye]

Not on my 2000. Not calling you a liar by any means, as maybe they changed that for my year or something.

I have a UG (Ultra-Gauge), and one of the first really hot days this year (3 weeks ago or so), I was in a blacktop parking lot, AC cranked, waiting for someone to come out of the store.

My UG beeped at me alerting me that the temperature was higher than my warning setting (212?) and by the time it shot up to about 220, my gauge was damn near close to the red line. Mine stays just under the middle for the range of about 188-195, anything less/more than that, and you can definitely tell by the gauge position.

 

[Turdle]

Yeah, I had a second mechanical gauge on the Turdle which was a 98, and observed a "working" stock gauge also. You could not read "actual" temp but it did rise in accord with the mechanical unit, and, scangauge 2 I was loaned to verify it all with.

Your gauge may be faulty.

 

[Cobraguy]

I may go ahead and test that.

What engines do you guys have? Factory?

 

[shadowless127]

My factory temp gauge accurately/directly represents the engine temp as displayed on my OBD II data logger. completely stock 01 5.0.

 

[BrianDye]

5.0, 160,000+
Stock besides cone filter, catback duals.

 

[Turdle]

My 98 had a modified, 347 engine, however the wiring and sensors were factory, other than a fitting for the mechanical gauge which was later removed for room.

I went to individual "cylinder head" temp gauges which actually were glorified coolant temp gauges directly in the heads. They also were right in line with the dash gauge now that I recall this.

 

[Dan Whitaker]

I had the speedo go bad in my cluster on my 97 Mountaineer and replaced it with a different year cluster. (I think it was a '96) The volt, fuel and oil gauges worked but the temp gauge did not. I tried using the original temp/fuel gauge cluster and the temp gauge still did not work so I ended up using an Autometer temp gauge.

I believe there were differnt ohm resistances used on different years of gauge clusters.

 

[BrianDye]

Now that you say that, I just remembered, my cluster is out of a 2001 Sport, (The white face cluster)

 

[jimwww]

Interesting. I heard from a mechanic that later Ford's temp gauge (mine works - I know as when I noticed it was barely getting warm even when driving and figured out that the thermostat was stuck open - replaced it and it went to dead center) now are dummy guages. Ford service departments got tired of people complaining where the gauge is compared to their friends. Has anyone heard this? Could it be true?

 

[masospaghetti]

I'm pretty sure you're right with certain vehicles, not sure about the Explorer though.

It makes perfect sense to me that they would calibrate a gauge to remain at a certain point to prevent the driver from worrying, as long as the engine was within operating temperatures, since the thermostat often opens about 10-20 degrees sooner than the fan kicks on.

I remember my old Chevy Beretta had a very accurate temp gauge and I would get a bit nervous when the needle would climb 3/4 towards HOT, then the fan would kick in.

For the record though, I (and probably most enthusiasts) would much rather have an actual accurate temp gauge than one set up to prevent people from worrying.

 

[jimwww]

I agree.

 

[Joe Dirt]

Why does the factory gauge slowly move up as the truck warms up then?

 

[jimwww]

I meant that some newer model lines have that (heard)- I think ours are too old for that. I think ours have the real gauges.

 

[yavapaires]

Exactly. On my 96, 4.0 OHV, you can see when the thermostat opens and closes. Watching that will drive me nuts. I just glance it every once in a while. I just wish the oil pressure gauge would work like that. I would much rather know what the oil pressure actually is, than to know it has at least some oil pressure. Hell, I would like to have a gauge for everything, like the old W900 Kenworth I used to drive had.

 

[windsors03cobra]

Real gauges was the only advantage I could see that a Chev S10 Blazer had over an Exploder. The oil pressure gauges read in PSI and went up and down with engine revs. I also guess the 4.3 Chev would dominate a SOHC but thats another topic.
Most all gauges in any car nowemdays are L_____H, C____H, 8_____18, I would really be sore if I bought a $50,000 F-350 super diesel and got crap ass gauges like that, tho I have seen some information centers where you can toggle through and see real values, the same values then PCM uses.

Push button/Electric transfer cases for the loss.

 

[MNgopher]

Not really anything new or unusual - pretty much every auto manufacturer does this some of their vehicles. There is a huge component of our society that has no idea that it is normal for things like oil pressure, temp, and voltage to vary somewhat during the operation of a vehicle. Any movement is taken as abnormal and leads to pointless service visits.

A common strategy is for the logic to allow the needle to move normally while in the warmup range of temps, and then deaden the response while in the "normal" range. Somewhere on the high end it will go up normally as well. I believe the temp guage in my '97 operates this way - the guage is pretty much rock solid at operating temp, even though it really fluctuates a bit. Once it exceeds some preset point, rises normally to the red (which I verified when my themostat stuck closed one time...).

The real guages in my '88 Cherokee (as inaccurate as they may be, but they move) still throw some people for a loop - why the oil pressure guage move so much, etc...