i have replaced radiator 5 years ago, radiator cap 3 months ago, replaced intake manifold gaskets 2 weeks ago, thermostat last week, temp.sending unit last week, coolant sensor last week, cooling fan clutch last week, and water pump 1 year ago, it only overheat's while sitting. but driving it cools down and is fine. please help me. i can tell you everything about the truck. truck does have 293,000 miles on it. was just told that my problem may be because i don't have electric cooling fans. i forgot to mention that my truck has a 3" body lift and 5" suspension lift. and my transmission fluid is going to heavy duty intercooler so that is not a factor with radiator. but when i lifted my truck the body lift raised the radiator and since my fan shroud had to be lowered with engine, the brackets for fan shroud to stay alligned with the mech. fan. the top 1/4 of the radiator is never being cooled when fan sucks in the air. and the first thing the cooling system is getting is the coolant from the top of radiator when thermostat opens. so i think that that is whats causing it will let you know what i find out. and my head gaskets aren't blown, neither is intake manifold, and ports are not being blocked off or clogged.

 

Have you checked the fan clutch? Check for play in the shaft and any fluid leaking. Spin it by hand when the engine is cold and see if it has a good amount of resistance.

 

Park it with the front right higher up than rest of vehcile. Let it run with cap off, heater turned on and see if you have air trapped in the cooling system. This is called "burping" the system. I suspect you have some airr in the lines somewhere.

 

i'd suggest a cheap infrared temp gun to measure the hose temps at the top hose and the bottom hose.

top hose should reflect engine temp.
bottom hose should be about 140-160-ish.
this indicates your radiator is cooling properly.

if its not cooling properly, consider that it might be stopped up inside with mineral/calcium, or stopped up outside in the air fins, or the internal transmission cooler temp is highly elevated.

or, you have a leaking head gasket. run a compression test or test coolant for combustion gases.

you said you replaced the clutch fan. does it have resistance when cold, also when hot.

 

With all that you've replaced,the only thing left is the waterpump itself...........Just a thought

 

He replaced it 1 year ago he said. The only thing "left" would be the head gasket, or a cracked head for that matter...and having air in the system....and having low coolant. If he's not losing coolant, it's likely trapped air. If he is, it's possible that he's got a blown head gasket or cracked head.

 

He said he replaced the fan but didn't say he replaced the fan clutch.

 

1st thing is to stay on top of the Q's being asked, it will only help resolve the issue..you said fan, do you mean fan clutch? as stated you can do a compression test and post the results and do it with the engine warm. You can check the oil color if you pull the dipstick. When the motor is up to operating temp are both top/bottom hoses hot? Does the overflow tank change volume levels before/after it gets up to temp, do you need to keep adding to it? What brand pump or where did you buy it? Also at what point did this problem start and what did you do SINCE then?