I would stay away from radiator/block sealant like that guy said already I think...I was considering using some on my truck, but after I read up on it for a little while there was no way in hell I was going to put that stuff in my radiator. Do the same if you wish, but all that you are going to find is people that put it in old beaters saying it works great, and everyone else saying it's just going to clog stuff up/temporarily fix it, and then majorly eff things up when it's done.

Like I said, I immediately threw that option out the window when I read up on the stuff, because it just seemed really sketchy.

 

Had the identical problem on my 06 ram 1500 with 4.7
Found bad head with slow leak of coolant into cylinder. It didn't show because leak was slow enough that catalytic converter burned it off.
Replaced heads and now fine. No codes anymore. No coolant loss.

Head replacement costs around $750 in parts and can be done in driveway over a weekend. Of course you could take it in for repair but be prepared for high bill.

I replaced both heads, gasket set, head bolts (these are tension stressed and must be replaced), chilton manual (or full factory manual available on ebay for $8), oil, oil filter, gal of antifreeze, some high temp rtv. Go for it. You'll be glad you did. The timing is different but is straight-forward and easy to do without any special tools. Just follow the directions in the manual.

You'll need to do a head job every 50-100,000 miles on most 4.7 engines. They are poorly designed in that you have aluminum heads mounted on steel/alloy block. That's a bad combination. Be sure to stress torque the head bolts. 1/4 turn in addtion to torque spec. Or you'll be doing another gasket replacement in short order. Thank Daimler Benz for the aluminum useage. It is a great source of revenue for the manufacturer.

 

Reading this scares the crap out of me, i hate when i read a thread like this with potential break downs in the future, i am changin my fluid today!! and hope i dont have these problems

 

I also plan on changing my water pump every 25,000 miles. I'm now on my 4th one (just installed it two weeks ago) and am at 80,000 miles. I had one fail after several miles. It was new and right out of the box. The bearing towards the radiator (outer one) gave up. The design is so flawed that many I've talked to replace them at regular intervals to avoid breakdowns while driving. Wish I had better news. The first was done at the dealer at a cost of $500. It was already too late for the heads though and when I picked up the truck it was missing. When I did the head replacment the mopar replacement was missing part of the impeller. This was after about 10,000 miles (that's how many miles I got with the misfire before I had to replace the heads). Of course I had to replace the water pump as part of the head replacement. It lasted several miles before coming apart like the 1st one (original from the factory). And I am now on my 4th one. I plan on replacing it as routine maintenance at 100,000 miles (if it lasts that long). Locally, I know one place that had 47 of these trucks/engines in fleet operation and they had similar problems. When they complained to Dodge/Chrysler they were told it was normal wear and tear. (This was the bol weevil project here in Texas). As the project was successful and is now ended, the manager told me his number one nightmare was over (the 47 Dodge trucks). As an owner I now know what he meant. I'm not on here to discourage others but to warn them about any overheating and what it will do. Aluminum heads with steel/alloy block. The aluminum expands much more rapidly than the steel. The thin piece of gasket between them gets damaged by the movement. Overheating increases this. The manufacturer doesn't stress-torque the head bolts for no reason. It helps the gasket for a while, but...

 

Could this be as simple as a bad radiator cap? When I lose coolant, the first thing I do is change caps as they actually open and close as the engine heat cycles. (relief valve)

 

Nope, but the 4.7 isn't really any more prone to overheating than any other engine. I have 92k on my 4.7 in the Grand Cherokee and personally know two people with over 225k miles on theirs without an issue.

The problem is, as Mellowde stated, WHEN one overheats for any reason (poor coolant, bad thermostat, water pump failure, etc.) damage is done rather quickly and it's usually very severe.

The key here is to take the preventative steps to assure your vehicle DOES NOT overheat! Proper fluid change intervals with quality fluids (the use of a product like Purple Ice couldn't hurt either), using a "fail safe" thermostat, etc. are all things you can do to assure you don't overheat and cause costly damage in an admittedly poor design...

 

I disagree. This engine is more prone to overheating as the water pump is to grades below sub-par. I've had to replace three times (that's 4 including the original) in just under 80,000 miles. I now plan to replace every 25,000 miles as routine maintenance. Most will not though which definitely makes overheating a real issue on this engine. I've had two outer bearing failures and one impeller disintegration on the first three. If I can keep the 4th running till 100,000 miles I'll replace it then. Couple that with the aluminum heads and you have a prescription for disaster. Tha't one reason why so many are writing in about the same issues (misfire codes and coolant loss). Others's are experiencing gasket/head problems without ever overheating (to their knowledge). With all the sophistication the designers of this engine were just a little too cutting edge. Anyone who is looking to buy this truck should consider the 5.7 L, in my opinion.