Hey all, I just got a P1281 code (engine is cold too long), and I replaced my coolant temp sensor. I did not disconnect the battery when i did it. Well my check engine light is still on, so any ideas of what else could be causing code if not the faulty sensor?
Engine is cold too long
- Thread starter Lb445
- Start date
Replace the thermostat with a new 195 degree replacement like from Stant. Make sure not to buy any claiming to be "fail-safe"... they aren't, they actually tend to fail more but in the open position.
The fan does not cool the engine, it cools the radiator. If the thermostat is closed (as it is at startup if functioning properly), the engine will get up to operating temp (195) regardless of what the fan is doing, and then the thermostat will open, releasing the hot coolant to the radiator to be cooled. It is at this point when the fan and fan clutch make a difference. The OP's symptoms point directly to a stuck open thermostat. A stuck fan clutch could exacerbate the problem if the thermostat is stuck open, but that is not the underlying cause here.
C.J. Roberts
TJ Addict
After replacing the sensor I ran it for about 20 mins with the radiator cap off + heat on to let air bubbles out and the gague was about 190 at the 20 min mark (normally stays around there when driving). I have not driven it since, since I'll be replacing my tstat.
Similar threads
