Truck Getting Hot

skippy7024 · August 10, 2010

I have a 2003 HD GMC Sierra 2WD. It has the 6.0 litre motor. I am having trouble with the truck running over 210 degrees while normal driving. I have had the radiator out sent to a shop and flushed and pressure tested. I have replaced the thermostat. I have replaced the clutch fan. The cooling is full and shows no leaks. Would the waterpump cause this problem? I am going to be towing with it next week and know it is going to get hot.

jro909 · August 11, 2010

water pump would be the only other option really, unless maybe the serp belt isen't tight and slacking on spinning the water pump...maybe an internal blockage but i'd presume that would cause bigger problems

redvett · August 11, 2010

Don't rely on the Gauge for accurate temp reading, have a tech use a scanner and read CTS readings you will then know if the engine is running hot or the Gauge is in error.

skippy7024 · August 11, 2010

I had a scanner hooked to thios and it said it was 235 degrees. I am with you I have seen that before also. The belt has been replaced along with the tensioner. It seemst be very tight and not slipping. I don't mind to put a water pump on, just wanting to see what other people thought.

desrtrat · August 11, 2010

did you burp the cooling system properly..still may have a air pocket.

skippy7024 · August 11, 2010

I think I purged it correctly. But I definitely would try again. Will you let me know step by step on how to purge it the right way. This truck had a overheating problem in the spring. That is when I changed the clutch fan, thermostat and had the radiator cleaned and pressure tested. My problem went away. I have towed on numerous occasions without ever getting over 210 degrees. Then last week when sitting at a red light it would start getting hot. I have a trip planned next week where I will need to pull my camper. I hooked up to my camper today and as soon as I had to go up and upgrade, it started climbing past 210. Once back on flat ground, it would start to cool back off.

jro909 · August 12, 2010

what are you pulling? and where?

skippy7024 · August 12, 2010

I have a 24ft camper. I am pulling it about 150 miles from my house. I use to pull this with a 1/2 ton 4.8 Chevy truck. Pretty embarrasing that I can't pull it with a 6.0 3/4 ton truck! I guess I will be going back to it again.

desrtrat · August 12, 2010

I think I purged it correctly. But I definitely would try again. Will you let me know step by step on how to purge it the right way. This truck had a overheating problem in the spring. That is when I changed the clutch fan, thermostat and had the radiator cleaned and pressure tested. My problem went away. I have towed on numerous occasions without ever getting over 210 degrees. Then last week when sitting at a red light it would start getting hot. I have a trip planned next week where I will need to pull my camper. I hooked up to my camper today and as soon as I had to go up and upgrade, it started climbing past 210. Once back on flat ground, it would start to cool back off.

with that info, it sounds like a air flow issue. i would check your clutch fan again.. i know you just replaced it, but new not always mean good.

good luck

skippy7024 · August 13, 2010

I agree with what you are saying. I will try and see if I can buy a better fan this time. Thanks for the help.

txab · August 13, 2010

I agree with what you are saying. I will try and see if I can buy a better fan this time. Thanks for the help.

Buy OEM.

skippy7024 · August 13, 2010

Bought fan and a clutch from GM. Normal driving got to 220 when sitting still for less than 2 minutes. Once moving cools back down.

skippy7024 · August 15, 2010

This seems to be an air flow problem. I have cleaned out the radiator and condensor. You can see through all the fins. I would do whatever it would take to fix this truck.

txab · August 15, 2010

Do you have all the shrouds in place to make sure all the air is directed through the radiator? Have you had the radiator "cap" tested? How about the entire cooling system? What kind of shape are the hoses in? Could the lower hose be collapsing periodically? And you say you've had the radiator taken apart and all the tubes cleaned out at a radiator shop? If so, not much left except to do the WP.

skippy7024 · August 15, 2010

I have already had the radiator rodded out. All the shrouds are on and original. I have looked at the hoses when it was getting hot. I could not see them collapsing. I have not had my radiator cap checked. I will try and get that done today. I will try and replace water pump next.