I have been looking through several post of late concerning overheating. There is a wealth of knowledge here, however I have seen lots of post with potential fixes but not the ultimate fix for said post. Well here was (key word was) my problem. My truck began overheating, not so much so that the "check gauges' light would come on but the needle was getting almost to this point. I thought that my t-stat was toast, so I changed it, not the fix. I did copious research and found that overheating in this truck is very common and the potential problems and fixes were vast. So I check the fan clutch, it was fine. Then I checked the temp across the radiator when my truck was hot. The top hose ( hot side) was 180 or so and the bottom hose ( cold side ) was 120. Also i felt of the radiator, it was very hot near the top hose, and most every where else was just warm. From my research, this screamed the radiator is clogged badly. At this point I talked to my local dealership and basically got the "well it could be anything just bring it in". What crap. I talked to a local radiator shop, told them my findings, and they said it was most likely a plugged radiator. Then the he asked what's it on. When I told him a dodge he immediately said its the radiator for 100% sure. I then changed the radiator refilled with zerex G-05 and all was well again. Look at the design of the radiator the tubes are small and flat (very small oblong orifice) basically the radiator is designed to plug with the first sign of corrosion. Sorry for the excessively long post. I hope this helps someone diagnose and fix an overheating dodge.

ps. changing the radiator was extremely easy, a lot easier that I anticipated.

 

If you did some searching here then Im sure you noticed most 4.7's that overheat is found to be cracked heads or bad head gaskets. Thats not to same ALL of them have this issue but more than half do.

A coolant system is very simple as you only have a few things. If you think it is the rad, the swap it out. Also change the rad cap while you are there. After that all you have left is the stat and water pump. The heater core is in there but the only way it fails is it if springs a leak.

Other than that you got your heads and head gaskets which seem to be a decent sized issue with 4.7s and overheating.

 

I'm having overheat issues right now. When I bought the truck, the water pump blew up so I replace it. Put a new thermostat in while I was at it and all new coolant. When the water pump went out, it messed up the fan clutch so I went to an E-fan. Probe is mounted properly by the top hose and comes on when it heats up.

Lately, the engine is heating up pretty quickly when driving (not so much when idling). Fan is coming on and sucking off the rad. No visible coolant leaks. Coolant is definitely flowing and full. Just put a 2nd thermostat in to be sure, no help. Changed oil when I got it too and the dipstick looks like good clean oil. No smoke coming out of the exhaust. Also, heat is hot for few seconds then gets cold. Already flushed the heater core and it didn't seem too bad.

Possibly related issue...It did have such a sweet idle, now starting to tick/knock. Knock gets louder when on the throttle, but disappears when you let off until it gets back to idle, then appears again. I also noticed that when it heats up (3/4+ on temp gauge), the knock nearly disappeared. At idle, the knock is rough enough to shake the truck a tad bit.

Per the cracked head/head gasket, wouldn't I notice coolant in oil and/or would be burning it?

Think I should I try another radiator too? Any ideas about the knock? Thanks for any help.

 

Get your truck warm and then feel the Radiator, feel ( us a IR temp gun if you have it) if it is warm (just warm) on part of the radiator ( it was the top tubes on mine) and smokin hot on another part ( on mine it was the bottom 6 or so tubes on the radiator). If this is the case the radiator is plugged. Also you can check the temp drop across the radiator. Us an IR temp gun and check the temp coming into the radiator ( the top hose) and the temp going out ( the bottom hose). If this temp differance is large (mine was 60º drop) this indicates a large residance time of the coolant in the radaitor which means dimishsed flow, which means the radaitor is plugged. If one or both of these is the case on your truck, go buy a radaitor, it was a very easy fix in my case, only took an hour or so to do the swap.

 

Thanks for the info. Old radiator had so much gunk in it, it had a hard time draining. I ended up grabbing a new radiator. Got it installed and no more overheating. Now my entire cooling system is new so I should be good in that area for a while.

Now I just have to figure out my ticking. I'm going to do some compression tests this week....but I'll save this for another thread.

 

Thats super good and cheap news.

 

I bought 04 with 4.7 after driving a couple of days noticed the temp gauge was running a little high took back to dealer they replaced radiator, thermostat and fan clutch it is running back at normal now