95 chevy truck running to cool
 

My 95 chevy doesn't get up to 195 degrees, temp of thermostat. According to the temp gauge it is running around 150 degrees. I have checked it with a separate thermometer and it appears the gauge is correct. My understanding is if it runs cold the computer will keep it running in cold mode and gas milage will suffer. Any suggestions welcome.


Thanks Ronnie

Did you check to see if it has a thermostat and what temp it is?

tstat may be stuck open or completely missing depending where you live or who had the pickup before you

I have had the truck since 97 and it has a 195 degree thermostat in it. My first thought was it is stuck open, I put a new one in it and checked the old one and it semed to be working ok. I forgot to mention that it is a 5.7 engine, if that helps any.

Thanks Ronnie

Does yours have an ECT sensor (for the PCM) and a separate ECT sender (for the I/P cluster)? If so, I'm not sure where you measured the temperature but you may not have anything to worry about. It's not likely that two difference thermostats show the same "symptom."

I am not sure I know what the ECT sensor is or the I/P cluster. I measured the temperture with a thermometer in the radiator.

Pardon me, ECT is short for "engine coolant temperature" and I/P, "instrument panel." And, a thermometer in a radiator is not really a good way to measure the temperature of the coolant where it counts (near the thermostat). Is the issue something new to this vehicle or are you just fishing?

Does the truck have plenty of heat? Take the temp of heat coming out of vents. Does that temp drop when driving.

Just to throw my .02 in my tahoe gauge always read around 150 but my hand held scanner shows the computer is getting the proper temp reading of 195 or whatever temp t-stat I put it in awhile back. I would assume the gauge on mine is taking temp from a different spot then the computer. Maybe possible thats what yours is doing.

theres usually a sender for the gauge and a sender for the pcm

My old 2000 Tahoe Limited (5.7) always ran with temp gauge only 1/4 of the way. By the gauge it was too low. Since I always had good heat I never worried about it. Although the last thin an Auto Technician never want to work on their own stuff.

Yes there are 2 senders and I replaced the one for the gauge when I replaced the thermostat. This is a new problem to this truck up until a few months ago the gauge read 195 degrees or just under the 210 mark, I have not check the temp of the heat at the vents but it had plenty of heat back during the winter. I will get a temp reading at the thermostat, I would think the housing temp would be pretty close to the water temp.

Just so we're on the same page, you replaced the sensor that takes one wire (for the gauge)? The ECT sensor for the PCM, on the other hand, takes two wires one of which is the ground reference (can't trust the ground provided by the water jacket for the precision it requires).

That is correct, it is located on the side of the head. Driver side between cylinders 1 and 3.

Check your water temp. If it is in fact running cold and you're sure the thermostat is good, replace the intake gaskets.

If the restrictors are blown, it never will come up to temp.

Allan

this one isnt for the PCM, it is for the intrument panel.

The DK GRN wire from the sensor (sender) ends up on pin 13 on the electrical connector at the I/P cluster (had to look it up). The movement of the gauge needle reflects the resistance change across the pin 13 and ground. Try unplugging the electrical connector from the sensor with key on, engine off after it's warmed up. The needle will drop with the resistance going to infinity. Thus, anything that affects the resistance measurement (resistance on the wire between the two end points, difference between the ground reference between the engine block and chassis grounding point for the I/P cluster, reference voltage which is the charging system voltage with engine running) will affect the position of the needle. What I'm getting at is, don't assume a huge mechanical problem.

Put gauge in head and to temp

These clusters were also known for not reading properly, so what you see may not be what the actual temp is. There are 2 sensors, one for the gauge and one for the computer. You should check to be sure the connectors are not corroded(also a common problem)

As it has been pointed out, a thermometer in the radiator is not accurate at all.....That temp will never be as high as the internal engine reading.

You do need to use a scanner to verify the gauge reading, which is the temp the computer sees. The truck should run consistently between 190 and 214.

Dude, quit making empty posts. It's obvious what you're doing, flashing the ad in your signature.

Cool running 1995 Chevrolet
 

I recently bought a used 1995 Chevrolet 1500 w/5.7. It had to have the head gaskets replaced so new gaskets and seals from the block up and thermostat. Temperature barely gets off the 100° mark. So not much heat for the winter. how do I fix this?