DodgeTalk Forum banner

Status
Not open for further replies.
1 - 20 of 54 Posts

·
Registered
Joined
·
39 Posts
Discussion Starter #1
i have an 05 1500 4x4 with 79,000 miles. It has ran fine then the other day on the hwy it overheated, so i stopped and let it cool down. it didnt leak any coolant so i figured the thermostat was stuck closed. well i put a new tstat in today and still does the same thing, from a cold start it takes about 5 min until the temp gauge is passed the red. It doesnt appear to have water in the oil but im still worried about the headgasket. could it be the waterpump? any help is appreciated.
 

·
Registered
Joined
·
1,709 Posts
check that water pump, let your truck cool off, remove cap, and run truck when stat opens you should see the coolent flowing in rad. do you have hemi or 4.7?
 

·
Registered
Joined
·
1,709 Posts
looking in the rad. if your not loosing coolant, and your oil is good, id put my money on the water pump. they are around 70$. get one from napa if thats what you do.
 

·
Registered
Joined
·
39 Posts
Discussion Starter #5
i was thinking that too, but the water is flowing through both hoses. i did a compression test and all were about 75. is that too low?
 

·
Dodge Tech
Joined
·
352 Posts
did you have the throttle blade open when you did the compression test?
 

·
Dodge Tech
Joined
·
352 Posts
that is why compression was low. but if it overheated on highway i would say not the fan. does the radiator get hot when after the thermostat opens up. you should be able to feel warm/hot air blowing from the rad. fan after the thermostat opens. If it feels like it is cold then you may/probably have a clogged radiator if the water pump is in fact working. So how do you know that coolant is flowing through the hoses?
 

·
Registered
Joined
·
1,513 Posts
what about the heater core?? If you turn your heater on, will the temps drop??
 

·
Registered
Joined
·
39 Posts
Discussion Starter #10
the strange thing is the temp doesnt drop when i turn on the heater, but now my heater doesnt blow hot at all. the rad does get hot in places when stat opens.
 

·
Dodge Tech
Joined
·
352 Posts
explain places. like sections of the radiator are cold or only half is hot and other is cold? and dumb question but is coolant filled all the way. and when you rev the engine does the heat come back? i mean a clogged heater core in theory shouldn't cause an overheating since it is on a secondary coolant passage.
 

·
Registered
Joined
·
39 Posts
Discussion Starter #12
i think the right half of my rad gets hot. the coolant is full and the heat doesnt come back when i rev or when driving.
 

·
Premium Member
Joined
·
30,924 Posts
froma past DT thread ... the thread was about check the heater core but most will still help you with your truck
====================

If you're hearing water running though your heater core, you have air in the cooling system. You need to park the truck in the driveway with the nose sitting higher than the rest of the truck. While the trucks engine is cold, get under the hood and remove the cap. Start the truck and put the heater on high-heat. Double check the level in the bottle and fill it up to the cold mark. Now just let the truck idle while it warms-up slowly. You need to be careful here because if the system has an air pocket, it could flash-boil on you. If it does that, it’ll push coolant out like “Old Faithful”; so be careful. As a safety measure, you can put the cap on but leave it loose. That way if it flash-boils, it won’t hose you down with hot coolant; not fun! As the coolant flows though the bottle, you can feel when the thermostat opens as the upper hoses gets hot. You need the thermostat to stay open a number of times because it the only way to get the air out of the system. Check the gauge on the dash from time-to-time and when you’re sure the coolant is hot, the thermostat has open-n-closed effort times, and the level in the bottle is full to the hot fill line, you can bet the air is out of the system now. Tighten the cap. Turn the heater off and you’re done purging air from the coolant system. There’s a purge tap on top of the engine but if the bottle is sitting higher, it’s the better choice. I’ve never be able to use the bleeder tap without getting hot coolant all over me and the whole engine. That and I hate the feel of coolant on my arms and hands.

Now you can check the cooling fan. Nothing is harder on the cooling system than the time the vehicle is sitting still with no air-flow though the front of the vehicle. When you first start the truck, you won’t hear the fan after the first few seconds. But as the truck just sits there, the air flow though the radiator gets hotter, and the fan clutch begins to get a little heat into it, the clutch will began to lock-up. You should be able to hear the fan pulling air though the radiator. Keep checking the gauge on the dash and watch where it peaks. Where does the gauge set as you drive down the road? That’s about where the needle should be now as your truck just sits with the engine idling. If the trucks temperature keeps climbing, you could very well have a bad fan clutch.

Move you hand across the face of the radiator. Check for cold spots or areas that seem much hotter than the rest of the surface. If the temperature isn’t uniform, you could have a plugged radiator core. Stop leak products have a bad habit of plugging good and bad areas within the core.

After checking all of this and the system just seem to be running too hot, you could have a thermostat that’s not opening fully. Checking or testing it will take more time than the thing is worth. They’re pretty cheap so just replace it. If you’re going to take the time to replace it, you need to make a choice; do I flush the cooling system or use the old coolant. And since you think there maybe stop leak in the system, you need make a choice about using an acid flush though the system. The acid flush should clean that crud out of the system. If you use the acid flush, you need to remember to open up the heat core as well.

:dtrocks:
 

·
Dodge Tech
Joined
·
352 Posts
it sounds like the rad might be clogged.
 

·
Dodge Tech
Joined
·
352 Posts
like i said before if you were driving on the highway (50+mph) and you were overheating then the fan shouldn't be the problem there should be plenty of air going through the radiator at that speed unless something is blocking it like a piece of paper or trash or something.
 

·
Dodge Tech
Joined
·
352 Posts
if there is only half of the radiator getting hot and the water pump is working then it sounds that way to me
 

·
Registered
Joined
·
1,709 Posts
the impellers on our pumps are plastic, I would check it, not to hard to get off. getting the clutchfan off is harder.
 
1 - 20 of 54 Posts
Status
Not open for further replies.
Top