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2005 dakota 4.7L V8 runs hot in hot weather

22K views 13 replies 9 participants last post by  MoPar Penguins 
#1 ·
Hey everyone!
I'm new to the forum and I did a search but I did not find anything so I apologize in advance if this has been answered.

I have a 4.7L V8 quad cab 6ft bed

So here's my issue:
My truck runs great in cool weather (like winter and fall) but once the temperature outside gets warm (80 degrees +) the truck runs hot. Especially when I have the A/C on and driving on the highway. It also drives hot doing about 40mph.

I cannot for the life of me figure out what the issue is. Has anybody heard of or had this problem? I have done extensive research and get so many different results. Some things work for one person while the same solution fails for someone else.

So I was wondering if anyone knows what the cause can be and what a possible solution is. By the way i have under 100,000 miles.


TThanks in advance for all your advice! It's greatly appreciated
 
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#3 ·
How hot is hot? Did you go by what the temperature gauge says or did you read the temp by an infrared thermometer? If it's actually running hot when was the last time you did a radiator flush or cooling system service. The radiator flow could be restricted by deposits. i have heard also about sludge in these engines causing them to run hot but I don't know if I believe that. My wifes 4.7 has never run hot in 87,000 mile but I do service the radiator regularly.
 
#4 ·
Jamesslcx, My 2010 Dakota 4.7 TRX4 has 18,000 miles. What happens during the summer with 80+ degrees: When I use the air conditioner driving local, start / stop, the temp starts rising going above the middle line on the guage. With the exception of hot days, the temp always runs normally below the middle line. If I drive 40mph and above, the temp stays below the middle line. I suspect my clutch fan is not sensative enough to turn on and be effective to cool down quickly. I have not seen this before on this truck. I did not have this problem on my 2003 Dakota 4.7 which I sold with 90,000 miles.
 
#5 ·
Wow! Nipper that's low mileage for it to be running hot. I'm interested in exactly how hot the engine is running. Do you have an infrared thermometer to measure the exact temp? You could be right about the fan but with that low of a mileage it doesn't seem like it would be faulty.
 
#6 ·
Running hot sometimes

Just got done fixing almost the same issues on my 05 Dak Quad Cab 4.7 used to run hot going up hill on my way home. Tried new thermostat twice even 180 deg from jet would be ok on flat ground but going up hill temp would rise and take a long time to cool back down. Flushed the radiator twice same thing got really frustrated finally replaced radiator with heavyduty one i found at local radiator shop for $230.00 installed with new coolant 180 deg thermo from jet performance reinstalled and thank god problem is SOLVED. No more rising temp
 
#7 ·
Running hotter in hot weather

Thanks Gents for the replies.... With 18,000 miles and based on what I have heard from others this is a common problem while towing with the AC in hot weather. AND, based on what others have done, installing a heavy duty rad makes me believe the factory rad is engineered to small. I don't have an infrared thermometer to measure the temp but watching it rise while driving gives me concern.... I did try a few experiments watching the fan clutch which cuts in at the "mid line" on the temp gauge and starts the cooling process. With that, I probably don't have a serious problem but would like it to run as cool as possible. My attemp will be to help the rad run cooler by installing a Trans cooler, and in turn, helping save/extending the life of my transmission. I have the towing package which has a factory trans cooling as part of the rad. My questions: - should I install the cooler before the rad or after? - I know all say installation should be directly in front of rad but what experience is out there that says different and where is the best location to install?
Thanks for your input.
 
#8 ·
Nice truck Nipper! I looked up your trucks spec's and it's very impressive. Your truck just may have an aux transmission cooler already installed, it being a TRX4. That's why this overheating thing is mind numbing to me because your truck is built to tow it seems. You may be on to something about your clutch fan, anyway this seems to be common even among 1500 owners as well. Some of them see a problem others say it's normal. Does your's ever overheat?
 
#9 · (Edited)
I use to own a 2007 Ram 1500 TRX 4X4 and it already had a Trans cooler installed in front of the radiator, AC also in front of Radaitor. Never had any overtemp problems with it. Loved the truck but had to trade it in on something else with better MPG. I would be looking at thermostat or fan clutch. How many miles under 100,000 do you have? I have seen (not ideally) no coolant change anywhere in the truck's life with no problem. So that leads me to believe it's a t-stat issue with the high temps and more load running the AC on the engine.

The t-stat should be a easy change just to rule it out of the equation. I would replace that before looking anywhere else.
 
#10 ·
My 2010 Dakota never overheated, but as I stated watching the temp rise while towing in hot weather has me concerned. I am extremely fussy about my trucks which could be part of my problem. My TRX4 which has the towing package, only has the factory rad with a built in trans cooler. I suspect I will install an additional external trans cooler.
 
#11 ·
I know I'm a bit late to the party, however I just had this same thing happen to me.

I completely rebuilt my 4.7 last December, which included a brand spanking new fan clutch. All has been well. That is, up until last weekend when we finally broke 85° and did it with a bang and hit 98° as our high (Hickory NC). Keep in mind, this happened with the AC on as well.

I noticed that idle tell temperature gauge would periodically hide the mid temp mark and sometimes go just above. This is very abnormal for my truck, as it has always run below the mid mark. I also have a digital scangauge (obd2 direct hookup) and I can set it to show any PID that the truck offers. I have mine set to voltage, water temp, instant mpg and avg mpg (because I like it better than the mpg reader that came stock).

Normal driving never usually goes above 204°F and at idle, never above 209°F

Well.... to cut this short, while driving this past weekend, I hit 222°F at idle, and would fluctuate between. 211 and 220 while moving. If I parked, I could watch the temp rise to 222 again, and if I brought the RPMs up to 1500, you would then hear the fan kick in, and thus the temp would drop to 204.

So, again, I set out to drive... and the same thing would happen. .... but I noticed, I couldn't hear my fan spooling up even when reading 218 or more.... I stopped.... opened the hood and tried to slow the fan by hand.... and no luck....

The next day, the same scenario. So I called up the parts place I got the fan clutch from when I rebuilt the engine and found it has a lifetime warranty. I swapped out fan clutches, and haven't gone over 204° since.
 
#13 ·
how do the fins look on the radiator? If you have too much rot in the fins, you're not cooling the engine.

I had a similar problem a few years back on my Neon. It was fixed after replacing the radiator. If you have that many miles, you're probably overdue for a new radiator.
 
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