Join Date: Oct 2010
Location: Sacramento, CA
tiredoltruck is offline
Re: 2003 chevy s10 gauge temp not reading
Check your coolant level. If you're running way low on coolant then the temp sensor reads low when theres no liquid in contact with it. Check this first, and before you drive it next IMO.
You might have a bad or sticky Theromstat. I'm fighting the same issue in my 96. I had to replace the radiator that was cracked and my new one has almost 30% more surface area than the stock radiator and the coolant was being overcooled. I managed to fix that by blocking part of the radiator.
If the coolant level is correct then you might wanna try removing the thermostat, button everything back up (including the fan shroud) and let the truck idle for about 5 - 10 mins. Check to see if the coolant gauge fluctuates as it did before while its running unobstructed. If not then your temp sensor is working. (the engine will run cool but shouldnt fluctuate). The thermostat is like a 6 dollar part at autozone, i'd start there.
Either way, excessive cooling and heating of the engine block will compromise the integrity of your cylinder walls, I wouldnt take it on extended trips before you get it figured out.
Last edited by tiredoltruck; 11-13-2010 at 07:17 PM.