damn cooling devils......

[gopher_6_9]

k, well here we go. Haven't posted much about this but I have been having cooling problems.

BeCool aluminum radiater
Stock stang t-stat (195* I believe)
electric fan etc etc.
Autometer gauges

k, when I drive it the temp climbs like normal (about 5 miles and it is at 190 on the gauge), but it keeps climbing till it hits 230* and then holds (appears to anyway) so I have checked everything I can think of, t-stat is opening, hoses are new and don't appear to be collapsing, etc etc. So I was talking to a buddy at work and he suggest hitting it with a ifrared therometer and see where everything is so I drive it and bring it up to temp today and here is what I see

Upper hose - 192*
radiater upper part - 190*
radiator mid/lower - 182*
radiater lower (hard to shoot so not sure) - 180*
t-stat housing - 203*(but I only shot it for about 5 seconds before the batteries died in the thermometer.

Now here is my question, anybody have any experiances with the autometer's reading wrong? based on the measurements I took and the fact that the thermometer is supposed to be correct (always been dead on when it was checked) everything looks decent but this is killing me.

so opinions please.

 

[TheUser]

i bought an aftermarket guage (sunco from autzone) and wondered if it was accurate. I actually pulled the guage, all the wiring, coolant temp switch and battery and went in the house. I boiled water in a pan and used a turkey thermometer to see how accurate the guage was. If you do this, you must also use a ground wire from the battery for the coolant temp sensor since it normally grounds on the intake. It's not really all that hard, but just kinda a hassle.

BTW, where can you get one of those infrared thermometers? I think I need one of those...How much are they?

 

[HISSIN50]

TU, how accurate was your gauge? ive always wondered.

 

[gopher_6_9]

the infrared thermeter is a Mac tools one..... if I remember it was like $125-$200 (not really sure) but it is handy at work for finding which cylinder is missing and stuff like this as well though I don't know if a hobbyist could justify buying one....

 

[PNY PWR]

I've always had to remove the top rad. hose and fill it. Air in the system can cause problems as well.

 

[gt90stang]

gopher_6_9,

The numbers you posted are exactly what they are supposed to be. I get the same numbers using thermocouples. Sounds like you might have air in the system.

Don

 

[TheUser]

TU, how accurate was your gauge? ive always wondered.

My guage was reading about 10* too high up until around 210" and then it was pretty accurate; I only went to about 220* because of time.

I would think that if the temps are fine in other places, they'd be fine at the coolant temp switch, right? Why would they read normal levels at the thermo, rad, etc and then jump at the coolant temp switch? I don't think air would cause that.

I would look more into the route of coolant temp switch, wiring, or guage.

 

[89MustangGX]

Where is the sending unit mounted?

 

[gopher_6_9]

Sending unit is in the top of the intake right before the t-stat, this is a carbed motor. oh and it is the proper autometer sending unit.

Ok, I have had systems with air in them before and all I did was jack the front end up and let it reach opening temp and then refill and I was fine, I tried it today and it seemed like I might have gotten a very little bit of air out (not really sure on that, but I am talking like very very little), is there another way? air is possible because the filler is lower than the upper radiater hose.

also before with the air in a system it seemed like it was actually overheating this one does not. it never boils over which to me if it was hitting 230 then it would boil over......

I am leaning more towards a gauge/sending unit problem.

 

[HISSIN50]

the systems should self bleed (closed system). that said, for many of us, they dont. i jack up the driver front end. take the cap off and let it run for about 20-30 mins.
some guys have removed the ECT sensor, to allow air to burp out down there. ive never done that.

good luck.

 

[89MustangGX]

Well, it's certainly easy enough to try another sending unit -- and if that fails, another gauge I suppose.

Autometer stands behind their products, and even though they only claim a 1-year warantee I have seen many times where they disregard that and will simply replace a defective gauge regardless of age.

 

[blk92stangg]

I tested my mechanical autometer against a digital turkey roaster in a pot of hot water. There was about a 3 degree diff between the two, which I chalk up to the mechanical gauge taking a little longer to catch up to the digital one. I didn't take it to boiling point, which in hind sight would have given me an absolute difference between the2 (dammit). Either way, the accuracy of the turkey thermometer is suspect anyways, so I just figured the autometer is accurate enough for the application. As far as the infrared thermometer, it takes surface heat temperatures, and I would suspect the surface temperature of something with a heat source beneath it would read cooler. With my car, with a 12 year old radiator, the temps warm up to 185, holds steady, until I hit traffic. It then will usually hit around 190 or so. If the AC is on, then it goes a little past 200. I also threw in a bottle of water wetter, which seems to help a bit.

 

[gopher_6_9]

Yep, thanks for all of your replies, I had already went over everything you have mentioned and it was all fine. I got it figured out though and Autometer had better have the new sender here QUICK.

I did the obvious, drove it till it "overheated" shot it with a I/R thermometer it checked fine (highest reading was like 205 or somthing)........ took another vehcile drove it till it was at temp shot it and guess what temps where the same DOWN TO THE DEGREE (with the exception of the lower part of the radiater which was actually cooler by 2* on mine). so this proves it is the temp sender and/or gauge. so all of this worrying and trouble shooting has been in vain as there was no problem to start with . Kinda pisses me off, don't get me wrong I am sure autometer will make it right with me, but that isn't the point I paid about $75 for a very vital gauge that is very inaccurate, but what do you do autometer is vertially the only big name gauge company out there.