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I drove about 10 miles on Sunday and all was fine. On the way home, my temp gauge pegged!
I had it towed home then replaced the thermostat.
Then I drove just a few miles and the gauge was perfect, right at 12 o'clock for the next few miles.
Then it started to rise and after another 203 miles the gauge pegged, just like before!
So the same thing has happened with both thermostats.
Today I shut it down at 3pm. At 8.15pm the engine was COLD and the temp gauge registered! It has never done this. It always starts at 9 o'clock. See pic below.
Is there a sensor that has gone bad?
Any ideas?
Thank you!
The question is, is the engine actually overheating? It might be burping coolant and obviously hot under the hood. Unfortunately the Northstar 4.6l engine is known for cooling system probems, including head gaskets. An air pocket in the cooling system could also affect the gauge strangely.
If it seems like its only the gauge, then yes the engine coolant temp sensor is what feeds the gauge. It could be the sensor itself or a wiring issue.
Today I ran the engine and it is still overheating as before.
- Both radiator fans are working
- I replaced the thermostat
- The engine coolant is topped off
What else can I try before taking it into the shop?
Could it be a water pump, or do they keep on running? I have never had to replace one, but it seems I'm out of options.
Temp gauge is pegged! 2003 Seville STS
