I was driving home from the beach on the highway and noticed my truck was starting to run warmer than usual. Usually it hangs around a little less than 210. On the highway it was running about 230 traveling at 70MPH not towing anything but with the A/C running on high and blowing nice cold air. Got into the city with some traffic and it hit 240. 260 is in the red on this vehicle. Dropped my friend off and when I was driving home alone I turned the heat on and it dropped immediately to 210. Since then I have replaced the thermostat and did a dump and refill which was about 2 gallons total. Since then it has not gotten as hot but at times has gotten to 230. Im not sure at the temp on the new thermostat. The package was bare and the people at napa were not very helpful but it is a gates thermostat and I bought the housing. Vehicle has a little over 80K miles on it. I did a complete flush when I got it with 53K miles on it. A mechanic looked at the fan and the water pump and said they were fine. What do I look at next? He said the water pump was good based on its not leaking. TIA!
2003 GMC Yukon overheating
- Thread starter mcrn
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Yes, it is possible the temperature sensor is bad. My LS400 had problem with temperature gauge, it showed cold while the heater gave hot air, replaced the temperature sensor fixed the problem.
Is it Love Bug season in your part of the state? I use to hate May and September when I lived in FL because of those evil bugs! I use to see quite a few overheated cars with plugged-up radiators...has the core been checked? It may just needed to be blown out with compressed air, or washed out with a water hose.
Think of it this way...if your windshield ever gets all gunked up with those little critters, imagine what your radiator might look like.
Think of it this way...if your windshield ever gets all gunked up with those little critters, imagine what your radiator might look like.
Thanks everyone. As a matter of fact it is love bug season and that day I was on the highway was terrible! I think I used most of my windshield washer reservoir on the trip cleaning my windshield off of those annoying bugs!! I will try cleaning that out today!! Thanks!
The thermostat rating is stamped on the thermostat.
You really should have looked at it to know what the heck you have in there!
WP impeller blades can corrode away or get loose. A tough problem to diagnose!
All of a sudden was probably the thermostat or the temp sensing system [sender, connection, gauge].
You really should have looked at it to know what the heck you have in there!
WP impeller blades can corrode away or get loose. A tough problem to diagnose!
All of a sudden was probably the thermostat or the temp sensing system [sender, connection, gauge].
Thanks mechtech. I believe it said 186. I will call a different Napa and ask them because you are right and I do want to know. I was hoping you would comment on this mectech. Any known problems with the WP on the 03 5.3's? Its the flex fuel if it makes a difference. Also if it is the sensing system is it a true temp then? Or impossible to tell? Thanks!
x2 on senders, gauges and wiring. I had a car that pegged the temp gauge and all that caused it was a loose ground!
No known issues with that water pump in our fleet, they typically last over 150k miles for us, sometimes even longer.
Real easy to change out as WP go.
No known issues with that water pump in our fleet, they typically last over 150k miles for us, sometimes even longer.
Real easy to change out as WP go.
I remember those [censored] Love Bugs when I lived in Louisiana. Man what a pita those friggin things were.
GM trucks are usually pretty good on cooling systems, other than water pumps. Many of the eventually blow up, usually by leaking. Radiators here and there, but not too often. I would check fan clutch operation, and verify the temperature with a laser thermometer if possible. Is the system low at all?
Also make sure there is no debris blocking airflow across the radiator.
Also make sure there is no debris blocking airflow across the radiator.
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That year model is also famous for instrument cluster problems, aka bad gage.
Thanks everybody! Coolant level is fine. No signs of any leaks. After saturnlove mentioned the love bugs i took the vehicle up to a diy car wash and washed the front of the radiator off with the high pressure wash and rinse. some love bugs came out but nothing bad. hte temp stays around 190 to 200 most of the time. But after about 30 minutes of driving the gauge will climb slowly over 210 and then shoots up quickly to 230 and stays there. now if I do turn the heat on the guage quickly does go back down to around 210 or less.
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