Temp Gauge

[Russell]

Hey guys!

I've got an odd problem with my truck. My temp gauge suddenly got rather high the other day, not enough to overheat, but like twice the temp of what it normally sat at. Anyways, It has always gone to the same temp since. So I dunno if my gauge / sending unit is having problems or something... I popped my hood after a long run and checked the temp just by how hot it felt in the engine compartment, it actually seemed cooler than normal, I was able to put my hand on the upper and lower rad hose without getting burnt, the heater hoses were similar, and the engine itself didn't seem too hot either (I could put my hand on the valve covers without it being too hot, and the heads didn't seem too terribly hot either.

Is there a problem with my cooling system or is my gauge just messed up?

[OrangeCrush1970]

Hey Russell, I just had this same thing happen to me this morning on the way to work. Did you ever find the problem?

Thanks,
Rob

[bigblock73]

Your thermostat could have stuck shut on you. Mine did it too recently, twice. I replaced the t-stat and it hasn't done it since.

[OrangeCrush1970]

Originally Posted by bigblock73

Your thermostat could have stuck shut on you. Mine did it too recently, twice. I replaced the t-stat and it hasn't done it since.

It's a new thromostat, I just put it in last week. 195 degree is what my haynes manual spec'd.

As for putting in a cooler thermostat, I would read this thread as it answered alot of questions suck as this.
http://67-72chevytrucks.com/vboard/s...d.php?t=239052

[Rooster's82]

Originally Posted by OrangeCrush1970

It's a new thromostat, I just put it in last week. 195 degree is what my haynes manual spec'd.

As for putting in a cooler thermostat, I would read this thread as it answered alot of questions suck as this.
http://67-72chevytrucks.com/vboard/s...d.php?t=239052

WOW, that was a fantastic thread, Thanks!

[Rooster's82]

speaking of t-stats, what is the advantage of putting in a cooler one?

[bigblock73]

Orange, mine was only a few months old too. Just because it is new, doesn't mean it couldn't have defects...or that there is something in your cooling system causing it to stick.

[Russell]

This happened well over 4 years ago, but yeah, it wound up being the gauge that went wonky on me

[imnezrider]

Rather than tell you about my own probs, I will attempt to throw some productive thoughts tour way. One simple way to test the gauge would be to stick the business end into a known water temp. You can also test the thermostat in a similar way. Submerge it and see if and when it opens. Keep in mind that new is not always good. Never overlool any logical possibility. :-)

[bigblock73]

Another thing, check to see if the overflow jug has more coolant in it than it did before (if you know if was properly filled to begin with). In my case, the jug was much fuller...meaning the engine was indeed getting hot, not just the gauge reading wrong.

[OrangeCrush1970]

WHOOO!!!! Well, that was a long chase, but I think I've got the overheating issue resolved. We did boil my thermostat, and it opened. Checked the water pump and it was doing it’s job so I pulled my radiator (Im running a 400 radiator on my 350) and took it to the shop to have it tested. Sure enough, there was some blockage so I had them core it out and rebuild it. Got it back in the truck and my temp gauge was still reading higher than usual (used to be about an 1/8 the way off the cold tick). I also noticed that the gauge would not fully set back at dead cold when I turned the key one notch (truck had not been run in 2 days). Could I have messed the guage up when it overheated? I went and got a new temp sending unit…same story. Now we did all the regular checking / precautious stuff and the truck was running like no bodies business so I decided to drive it around. It never overheated, the gauge never got above a little past half way, so in my mind the gauge may have been defected by the overheating. My thoughts are that the original thermostat that I replaced 2 weeks ago may have been rated at 180 degrees, and on top of that stuck OPEN because my truck always ran cool (which I know is not good in the wear department). Im currently running a 195 degree therm. Thoughts?

Oh, thanks for letting me find my way into the ‘younger’ truck thread!