Overheating issue

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atltopdog

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Hello guys , my 02 ram 4.7 seems to run hot in traffic but runs cool when driving. I changed the fan clutch but it still runs hot if I sit for a long time.

I know that this should be an air flow issue and I thought that the fan clutch would fix it but it didn't. The radiator was put in new 2/3 yes ago. The thermostat and water pump was replaced a little over a year and a half ago. I have tons of heat. The cap was just replaced. I've bled the system, and still no luck.

I'm planning on pressure testing the system once I can locate a tester.

Any suggestions?
 

Ian_Olivas

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could have air trapped in the system, leave the cap off and let it run, put some gloves on so you don't burn your hand and grab the hoses and squeeze them a few time to try and purge the air out. but your thermostat could also just be bad even if it was replaced a year ago, might even be the water pump if its happening at a stand still
 

SYKRAMMAN

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^^^Agreed. Especially if you bought a aftermarket pump, it’s very common for parts store parts not lasting, their good for some things but pumps, sensors etc etc, I’d go oe. Does it cool down when you turn the heat on? If so then not water pump, probably just needs another bleeding. Had to bleed mine 4-5 times to get it cooling right. When you bleed it, try facing truck up hill a little, it helps get the air out. It could still be the thermostat because there is a bypass that lets coolant constantly flow to heater core. Jm .02
 
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SYKRAMMAN

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^^^Agreed. Especially if you bought a aftermarket pump, it’s very common for parts store parts not lasting, their good for some things but pumps, sensors etc etc, I’d go oe. Does it cool down when you turn the heat on? If so then not water pump, probably just needs another bleeding. Had to bleed mine 4-5 times to get it cooling right. When you bleed it, try facing truck up hill a little, it helps get the air out. It still could be the thermostat even if you have heat because there’s a bypass that allows coolant to constantly flow to heater core. Jm .02

Site mod please delete this quoted post I made by mistake. Thank you.
 
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atltopdog

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Thanks for the feedback. I've bled the system in the past many times, but never this issue.

All of my hoses were hot. The radiator at one point was colder up top and hot at the bottom. While driving with the new fan, the car runs cooler. But if I sit in traffic about 10 min. The temp goes up. Once I start driving, even at low speed the temp drops to normal. My heater cores not leaking. The water pumps not leaking or making a grinding noise. The truck was running fine till one morning it just ran hot on my way to work.

I'm going to buy a new thermostat first. And pull the water pump and inspect the blades. After that, I'm lost.lol
 

cat199

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What about your fan shroud? Is still in place, and in good condition?
 

fastf

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Question how hot did your truck run and how long did you run it until you realize it was running hot.If you ran it for any period of time you might be on the verg of a head gasket going bad.Also when you replaced the radiator and the water pump did you flush the crap out of that engine and heater core?You could have a new pump and radiator but there is junk still in the core and the engine block.
 

fastf

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One more thing I forgot to mention just because you replaced the radiator two years ago the corrision from antifreeze and rust.Well it gets inside of the flue and stops up your radiator.Radiators now days are made or aluminum and you cannot rod them out like the old brass radiator.Your radiator maybe trying to stop up also while you are fixing this and checking that replace hoses if haven't been done but really flush the crap out of things.
 
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cat199

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One other thing came to mind— what’s your antifreeze level? Too high a concentration will cause an overheat under load. 60% and higher will cause higher running temperatures. At 50% you lose a little bit of cooling not enough to really matter but the higher concentration the more cooling ability you lose, and it gets progressively worse the higher the concentration. And its under load when it shows up.
 

NCRaineman

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One other thing came to mind— what’s your antifreeze level? Too high a concentration will cause an overheat under load. 60% and higher will cause higher running temperatures. At 50% you lose a little bit of cooling not enough to really matter but the higher concentration the more cooling ability you lose, and it gets progressively worse the higher the concentration.

It's surprising how many people don't know this. 50/50 mix is ideal in most areas, but if you are in a place where it doesn't get very cold in the winter you can actually dilute that even further. It is WATER that cools the engine, the anti-freeze is primarily there to... ... ... keep said water from freezing.
 

fastf

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If you add water and not equal things water will cause rust.Drain the water out and not put antifreeze back water will rust things .Only add water if you are running hot and don't have no choice but drain that stuff out after you can get the problem fixed.
 

cat199

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Minimum antifreeze that still protects metals is 40%.
 

SYKRAMMAN

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There’s a couple reasons an engine needs antifreeze/coolant, it has a higher boiling point, lower freez point, has rust inhibitors, and a few other reasons that it’s needed. The hoat G-05 I use recommends no lower dilution than 50/50 and no higher then 70/30.
 
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atltopdog

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I've only filled it with 50/50 antifreeze. I don't have any water in oil or sludge under my oil cap like a had on a previous engine that had a blown head gasket.

I've bled the system many times and still a no go. The only thing I can think of is another radiator or water pump.

The radiator about 2 yrs old and the thermostat and pump only a year old. I've had more than my share of issues with this truck. (Ready to trade it in for a old Civic) I haven't found my problem. But I will update you all when I do.
 

cat199

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Is the water in the radiator reservoir foamy?
 

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