Last weekend when replacing the valve cover gaskets, I noticed my coolant was at the "low" line in the reservoir. I filled it up to the "full" line with 50/50. 2 days later, it was back at the "low" line. I released the pressure on the radiator cap, then opened it and filled the radiator with 50/50. That didn't move the level of the reservoir, so I filled it back up. Today, I noticed that the dash sensor shows between 130 and the left "normal" marker. I ran a couple of errands, and it basically didn't change at all. I have not had any coolant puddles in my carport, but it has to be going somewhere.

Something isn't quite right. What should I check? Through a forum search, I've determined that the sensors go out fairly regularly. Is there a way to check it, or do I just replace it and hope that was the issue?

To my knowledge, the cap is the original. I'm not sure about the sensor. Is it located behind the alternator?

 

So I'm not alone with this. I have replaced the thremostat and the coolent temp sensor more than once over the last year or so and It's still not reaching the 195 deg.

Still 180 to 187 deg. Trying to find someone to power flush, not just replace the coolant.

 

I'm in the same boat, but I haven't replaced the coolant temp sensor yet, but I'm not particularly hopeful. Mine doesn't even get over maybe 170* or so though

 

There's a certain voltage it should have you can check with a multimeter but I dont remember the specifics.

 

Best thing you can do is get a scan tool that reads live data.

After the truck has sat overnight, go plug in the scan tool and turn the key on, engine off. See what readings you are getting from your coolant temp sensor and your intake air sensor. Those two numbers should be really close to each other, at least within a few degrees. If both sensors read nearly the same chances are they are just fine.

Next, start the truck and run it up to operating temp. This time check the coolant temp sensor on the scan tool and compare it against what the gauge on the dash is saying. If those number read the same, then again chances are the sensor is fine and the gauge on the dash is working properly.

Then I would start checking for mechanical issues such as the thermostat, heater core, fan clutch etc.

 

Brink (or anyone),
Can you tell me where to get a live scan tool? Or a name brand that's dependable? Then I can look and find the best deal on a good one that will last.

 

I bought mine off Amazon, I got the Actron CP9575 Autoscanner.

 

Check your local parts stores, and see if they have one they will plug in. That's free.

 

Update. Haven't used a scan tool yet due to traveling, but checked coolant on Thursday and was about 5"-6" over the full line in the res. Used a turkey baster to get it back to full. With my family, drove my truck and trailer to Alabama (3 hrs). Coolant dash reading got into normal range once or twice, but for the most part stayed around 130 the whole time. Truck performed great the whole trip. Leaving for home later today. Will check level in res before heading out

 

Keep in mind, there are two "full" marks on the reservoir, full cold, and full hot.