Overheating Problems 98 K1500 5.0

[Draco5185]

About a month ago I noticed my truck running a little warmer than it normally did. At first I didn't think anything of it until it happened again especially with my temp gauge not reading properly due to needing the sending unit replaced. Recently I replace both the sending unit and the temp sensor on the intake and the thermostat and let's just say that opened a bag of worms I wasn't ready for. Come to find out my radiator was clogged so I replaced it and yet it still climbs up to almost 260. I've bled the air out of the system like I'm supposed to but I'm stumped on what else I can do to fix my problem. Any advice or guidance would be greatly appreciated as I need my truck going ASAP.

 

[Erik the Awful]

What was your radiator clogged with? Mineral buildup? Acorns? Fourteen tubes of Stop Leak?

Is your upper radiator hose getting hot? If not, your thermostat may not be opening to allow the coolant through the radiator.

Is your water pump actually making coolant flow? Sometimes the impeller can break loose.

 

[Draco5185]

Back when I first got the truck 3 years ago I had no clue that the guy had only ran water in it. The water that came out when I put the new radiator in was rust colored. I also noticed what looked like someone tried using JB Weld to patch a leak at some point. The upper radiator hose was mildly warm but not hot but the gauge was up past the 210 mark. The water pump in about 2 years old at the most.

 

[Erik the Awful]

The upper radiator hose was mildly warm but not hot but the gauge was up past the 210 mark.

Replace your thermostat.

 

[Draco5185]

I'm going to give that a try and if it works I will for sure let you know. With it being brand new is there a chance I got a defective one?

 

[Erik the Awful]

I breezed through your original post and didn't catch that you've already replaced the thermostat. Let's go a little further. Did you check the upper hose right when the engine reached 210, or did you have the engine thoroughly heat soaked? When you say "warm" do you mean a little more than room temperature, or almost too hot to leave your hand on it?

How did you bleed the cooling system? Did you park it with the nose uphill? Did you use a Lisle coolant funnel?

 

[Draco5185]

The upper hose felt luke warm. I have my truck parked on level ground and I planned to use a Lisle funnel but none of the adapters would fit for some odd reason so I did it by having my wife watch the gauge while I kept coolant going in and up to the level where the cap goes on. I did make sure to have her cut the truck off before it hit 260.

 

[Erik the Awful]

That sure sounds like a bad thermostat. I don't know your experience level, are you sure you put the thermostat in facing the correct way?

 

[Draco5185]

I made sure to put the new one in tthe same way the old one came out. I'm no master mechanic or anything. I worked at a mechanic shop and would ask my coworkers about what I should do to go about fixing my issues.

 

[Draco5185]

Update on my truck and it's overheating issue. I took off all of the hoses for the cooling system and found that they were all caked up on the inside with rust and decided to play it safe and replace them all. I've only got a few more left to replace before I refill it with coolant in hopes that it solves my issue. Does anyone know what size hoses are needed for the small ones coming off of the water pump?