Can I just say...

engelme

True Classic
I love technology, particularly in its simplest application. I just bought one of those laser thermometers from harbor freight to satisfy me that the feedback I get from my dash temperature gauge is accurate (I don't think it is most of the time). Perhaps better yet, this clever little gizmo makes it largely unnecessary. I spent a few minutes collecting data in a "point and shoot" fashion and learned that the aluminum radiators do a great job, but that my dash gauge seems to be reading low based upon readings at the thermostat and the hoses leading in and out. After a vigorous run in 95 degree heat, my dash guage read 120 to 130. Here are the readings from my data collection.

Expansion tank (top): 170.5 F
Expansion tank (bottom): 155 F
Valve cover (driver side): 190.5 F
Valve cover (passenger side): 174 F
Thermostat housing: 175 F
Tstat hose (top): 160 F
Tstat hose (bottom): 170 F
Radiator (passenger side): 165 F
Radiator (drive side): 125 F

Admittedly, because some of these surfaces are reflective, the data might not be absolutely accurate, but hopefully relatively so.

Of note, occasionally (but not really predictably) my guage on the dash will rise to the 160 F range, but I haven't seen it at 190 F for a long time now (since my drive back from Ohio). My interpretation is that my Tstat is likely stuck open and that my engine operating temp is a little on the low side (maybe in the 170-175 range). I lose a little heat as coolant runs to the radiator, then really efficient cooling as it passes through to the other side. Indeed, I've only heard my radiator fans come on one time after the car was sitting at idle in the hot sun. I also suspect that my dash guage is only showing the correct temperature occasionally, either because of the sensor in the Tstat, the gauge self, or some connection in between.

Thoughts from others?

As long as I've got my laser thermometer, I can feel a lot more confident about performance of my cooling system, and that's a great thing here in the intermountain desert.

Cheers.
Mike
 
Interesting tstat observation

I was doing the same thing with my HF infrared doo-hickey a few weeks ago. In my case, the temps seemed to match up with the gauge pretty well, so I have that going for me.

The temps are lower than I have ever seen on any of my Xs, so I also came to the conclusion that my tstat is stuck open. Of course I dont even know if there is a tstat in there or not, since I have only had the car for a year or so and haven't had any reason to crack the tstat housing open.

Ever since I put the BobG rad in I have noticed that the temp gauge doesn't make it to 190 unless I let the car sit and idle till the fan comes on. When driving it is about two ticks below 190. I took an hour long cruise on the back roads Saturday morning. Here is the temp on the way home about 45 minutes into the drive. Crappy pic because I was driving. :)

20140726_104834.jpg


I talked to one other BobG rad installer that thinks his tstat must be stuck open. Just weird to find 3 folks all thinking along those lines. It certainly could be 3 stuck stats, juts odd. Whatever it is, I like it. It is nice to look down at the temp gauge and not get that sinking feeling.
 
Sounds low...

It sounds like you're not reaching operating temp. You should find your gauge at 180ºF to 190ºF in a few minutes of driving. Either you have an incorrect (low) temp thermostat or it's starting out partially open.

You too Jim. :)

The gauge isn't necessarily accurate, but is sort of for reference, meaning you should learn where it usually runs. If you suspect it reads low, it's likely resistance in the circuit (low resistance = low gauge, no resistance = high gauge) usually at the back of the gauge where it connects to the printed circuit. Fiat used steel washers there which rust causing resistance. Clean and replace with brass washers.
 
It goes without saying...

That I'd rather have this problem (stuck open or low temp Tstat) than the alternative (stuck closed or high temp Tstat). However, I would like my gauge to read close to accurate if possible. I can certainly check the connection at the gauge. Question....Does the dash cluster come out easily? What is the easiest way to remove it to get a look at the back? This could be the time to do the LED upgrade to the dash lights too.

Point of information, the car being referenced is Mia, which used to belong to Chris Layton and I then purchased from John Slagel back in January. Matt B. installed the new radiator and fans and I drove the car back to SLC from Columbus. On the first day driving back, initially I had normal operating temps, but as the day went on the temp readings on the dash gauge fell to the 160 range, through a period when the gauge read between 130-160 with sporadic rapid swings/spikes if the gauge needle, and ultimately settling at 120 nearly all the time. The gauge occasionally reads as high as 150 for very brief intervals, but largely it spends its time near the 120 reading (this in the context of the readings mentioned in my original post. Matt and I chatted about this and he agreed that the Tstat was likely stuck open and with the new radiator, temps were just remarkably cool. Because the electrical connections are pretty simple, it didn't seem there was much to go wrong. But I would like to have a look. Cheers.
 
Mike... what you observed and all Jim and others said...

is really pretty right on.

If you have ever opened up the cluster you may have tweaked the gauge needle... or the copper may be corroded on back...

BUT... the gauge is for reference... and your laser-therm is probably pretty damn accurate. You only need to know what "120" represents, which is actually about "175" in your case.

NOTHING is more accurate than Mama's Meat Thermometer though! When she's out shopping... grab it and dunk it in you reservoir. I used TWO of my wife's... and I found my dash gauge to be right on!

Since purchasing my HF laser... I have gone around and checked temps on everything, even grandkids! I found it to be very accurate and ALSO a useful tool for diagnosing auto temps in headers, radiators and engines.

I'd pull the cluster if I were you and clean it up, start the engine, test with your laser (and also compare it to another car to prove its correct) and then tweak your needle so it is pointing correctly.
 
Sure... There are also several others that have...

written and posted fotos... but I'll give you the basics and some tips...

It will seem a bit like much but the task becomes second nature after three or four hundred times...

1. Open Hood and remove LH grid near the cowl. The factory installed ONE screw underneath... a stubby Phillips should get it out... don't bother reinstalling it.

2. Unscrew or un-clip the speedo cable.

3. From drivers seat... remove FIVE Allen-head screws... then using LONG arms or a friend, reach around and PUSH on the speedo cable sheath while "fingering" the cluster to gently, but ASSERTIVELY, pull it out a few inches... USE PATIENCE! Once out a bit...

4. Disconnect the THREE connectors to the wiring harness. All are different, no chance of mixing them up. Push and pull the remainder of speedo sheath through a (usually) tight rubber grommet until the cluster is free. I just thought of the possibility of using WD40 and lubing the speedo sheath a bit to possibly make it easier to remove... Hmmmm.

5. I don't fully remember if you can get to all or some of the gauges from the back side... but the circuit board should be exposed so you can loosen and clean things up from the back. But usually you'll want to remove the clear plastic cover. Do this by placing it face down on a towel, and using a VERY sharp drill on the BACK SIDE... drill off the flared end of the long rivet QUICKLY. If the rivet starts to spin... it could ruing the plastic. STOP... find a way to stop it from spinning using a screw on the front side and vice grips... and drill again from the back. USUALLY, the first 4 come off quickly and easily... its always the LAST one that will give you trouble. (Murphy was an Optimist!)

6. Plug the cluster back in and "adjust" the needle as necessary when the engine is at temperature.

7. When reinstalling... I find it easier at times to undo the speedo cable at the trans and pull it back a bit. Now is a good time to see how free it is... lube it with white Lithium grease... or cheat a bit using WD40 sprayed in both ends... then reattach the cable sheath to the cluster and install it. Go to the rear of the car and push the cable while turning back into the gauge. Look through the rear window and watch the needle jump as you spin it.

8. This would be a good time to replace or upgrade the "cards" and needles also if you want... Makes for a great rainy day project.

HTH... Do a search for yourself as well...
 
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thermo

it is a two stage thermostat. it is open and the flow goes one way and as it heats up it changes the direction of the flow through the housing. same as the 124 twin cam engine as in the scorpion. 3 hoses in and out. so many customers (124) and exers installed the thermo incorrectly and complained of such. the 124 engine had the thermo in a one piece housing and was easy to install wrong. AND the lancia altho, looked the same as the 124, hooked to the hoses in a different way.
that's my story and I am sticking to it!:whistle:
mikemo90*aol.com
 
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