My 96 suburban k1500 won’t get up to temp. It stays at the 45 degree. I’ve changed my thermostat numerous times. Relays, temperature sensors, etc. I can’t figure it out.

 

how do you know its getting so low? not sure about the temp in your area but the water temp should at least be warmer than the ambient air temp

 

Did you feel (for just a second, if hot) the radiator hose, the heater hoses to/from the firewall after 15 minutes of driving? If hot, then I suspect the temperature sending unit.

 

also you have a temp sensor and temp sending unit. one goes to the ecm (in the intake) the other to the gauge part number tu230 from autozone(in the drivers side head)

 

yes the top radiator hose gets hot to where I can’t touch it. The two hoses going into my firewall to the heater core don’t really get hot. Which would explain my heat problems but I don’t think it has anything to do with coolant temps. I may be wrong though.

 

Good. That's more than 45°C; 45°C is merely an average summer day temperature in the shade here in Arizona. But there is no shade....an infrared heat gun would provide confirmation of the actual temperature, but may not help much here.

Still sounds like a malfunction in the sensing sender or related...


Sorry - turn both front heater and rear heat on high after 15 minutes and re-try this test. Agree - this likely has no effect on the low temperature reading.

 

Hi,

it is most likely that your temp sending unit is faulty. Luckily, they are cheap and easy to replace.
Other possibility is that there is a fault within the instrument cluster.

 

i know you said you replaced the sensor but what about the sending unit?

 

Ha ! Reminds me of the time when the oil pressure reading on our 1988 Suburban was bad; I had the factory service manual then, it said the sender for the gauge was hidden under the distributor at rear of engine, and I never would've found it there. I went to parts store and the replacement part did not look at all like what was threaded in there. It turned out that the service manual was wrong, that location was for the idiot light switch, and the gauge sender was actually underneath by the oil filter. Since I had the manual, I initially believed that, and never looked under the engine myself until I figured out that the book was wrong !!!

 

Yes I’ve replaced both the sensor and the sending unit. Still no luck.