2000 Silverado 5.3

[Mod_12]

I think I have a simple question for a 2000 Silevrado 5.3. How comes I can take off the radiator cap when truck is reading 210 deg after a day of driving. I see no leaks and it never needs antifreeze. I can sometimes hear gurgling when pulling out from a complete stop. When I remove cap the is no presure and no noises @ all. Already replace rad cap with new GM and did not fix it. It has never over heated or gotten above 210. When you remove the cap with truck running there is no movement of the antifreeze. Shouldn't it be flowing somwhat in the bottle?

Also on the heater I only have # 5 on the fan that works. I slowly lost other fan speeds over the last 2 weeks. How can I tell if it is the heater swithes or the heater unit itself. When I turn it on to #5 it dims the lights hard for a second .

[maddogg45]

Originally Posted by Mod_12

I think I have a simple question for a 2000 Silevrado 5.3. How comes I can take off the radiator cap when truck is reading 210 deg after a day of driving. I see no leaks and it never needs antifreeze. I can sometimes hear gurgling when pulling out from a complete stop. When I remove cap the is no presure and no noises @ all. Already replace rad cap with new GM and did not fix it. It has never over heated or gotten above 210. When you remove the cap with truck running there is no movement of the antifreeze. Shouldn't it be flowing somwhat in the bottle?

Also on the heater I only have # 5 on the fan that works. I slowly lost other fan speeds over the last 2 weeks. How can I tell if it is the heater swithes or the heater unit itself. When I turn it on to #5 it dims the lights hard for a second .

On mine you can only see in the over flow tank, unlike all the cars i have owned you could take the cap off and see inside the radiator.. there fore you would not see any movement if it is to temp,if you did take a radiator cap off when it was 210 you might get a hot surprise..

[Mod_12]

Thats what I mean I can take it off when it is at 200+ and it does nothing. It is like there is no pressure in the system. You see no flow when hot or cold in the bottle with cap on or off. I was thinking head gaskets or water pump but I am not losing any fluid or see or smell any burning.

[brcidd]

For the blower motor- you need to replaced blower motor resistor (high speed relay is built into this board as well- Follow wires back from blower motor to unit to identify it.

[j cAT]

your vehicle does not have a radiator cap it is a coolant pressure cap. there is no over flow tank that is the pressurized container which is part of the coolant system .

the temp should be at 195 deg f. if its at 210 deg f then its on the high side.

the fan issue is the resisters which are next to the blower motor under and behind the dash . the reason you have max speed is because this is a separate circuit. only the lower speeds use resistor circuit .


with sounds inside the vehicle coming from the heater core. this means you have some air trapped in the system . when the engine is cold remove the coolant pressure cap start engine idle until engine at normal temp rev engine to 2,000 rpms a few times then fill to the full hot mark. this is quite common .