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2006 Ram 4.7 Quadcab 4x4. I heard about all kinds of problems with this engine and now i've got one. 44,000 miles the bottom radiator hose clamp broke and it leaked out some anti freeze. Replaced the clamp and topped it off with the bleeder open. Now it runs a little hotter than before. The gauge stays slightly below center when it used to hold at around a quarter. So i ask a friend who owns a 2003 {and is also a mechanic} and he tells me these engines are having all sorts of problems. On his the upper radiator hose exploded at about 42,000 miles. Now his also runs hotter than it used too{slightly below half like mine}. He changed thermostat,radiator and flushed the system still the same. So i started checking around the web and it turns out a lot of 4.7's are having this problem and nobody seems to be able to fix it. On mine one side of the radiator stays cold all the time but when i checked the engine with a infrared heat gun it is between 165 and 185 degrees. The passenger side of the radiator almost two thirds the way to the drivers side varies from 70 to 90 degrees then it goes up to 175 from there over to the drivers side tank. I noticed that when im driving it if i punch it from a stop on a right turn the temp drops dramatically for about 20 seconds and then creeps back up to the midway point. This seems to happen much more around a right turn than a left or strait ahead. I was thinking maybe damaged water pump vanes but apparently a lot of people with this problem have changed them with no results. My friend seems to think that something in the engine cooling passages gets clogged. I'm just curious if anyone else has a 4.7 with similar issues. I've also heard they are notorious for sludging and losing oil pressure as well as head gasket issues which could explain my friends blown upper hose and my lower hose clamp breaking. Apparently some are blowing up the reservoir tanks as well.  

440 a few things..

this thread is going to get a lot of hits the way its titled..

when ever coolant is lost..  the engine can overheat..  hot spots form in the hottest parts of the heads.. the heated beyond normal areas expand more .. the head gaskets on this should be multi layer steel.. they don't crush. the expanding against the rigid surface causes the head surface to distort.. when it returns to normal temps. this reduces the clamping force on the head gasket allowing combustion gasses under high pressure to start leaking into the cooling system..  

replacing the thermostat is always a good thing.. as the wax pellet inside the thermostat when its exposed to overheating temps will usually force past the seal .. this reduces the amount of wax to push the valve open against the big return spring..  this will cause overheating issues like you are describing where the cooling system just does not seem to be working properly...

i normally take the thermostat out for a TEST ONLY.. to see if the water pump is circulating the coolant properly..  this is a TEST ONLY...    

next.. i will either remove the rattle valve from the new thermostat.. or drill a 1/8" hole in it.. so any trapped air in the system can get past.. or combustion gasses can get past..  this is a partial fix only..   the engine still needs work. but it might work for a long time like this...


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i came up with a test a while back. to test the combustion chamber sealing... this works better in a shop as you have compressed air.. and almost always a compression tester..

rig up the compression tester hose to hook directly to the shop air quick connect..   i have had to take apart the compression tester quick connect.. or remove the gauge from the top and use a quick connect plug there.

take out the valve core from the end of the hose...   please save it.. they are specials.. only look like a tire valve core..

i normally fill the radiator too the neck.. or use my radiator pressure adaptor with a piece of clear vinyl hose  that i hang off the hood latch..   i figure a way to fill this part way...  so any movement will be easily seen..

i remove only one spark plug at a time.. screw the compression tester hose in..    use the remote starter switch to bump the engine around to bring that cylinder to top dead center on the compression stroke..

i then charge the compression tester with full shop air.. (i normally pull a large vacuum hose off the intake manifold or  hold the throttle body open so pressure cannot build up when the engine spins)    the engine is going to spin sometimes..  so keep clear of the moving parts..   if it spins.. just reset with the remote starter switch..

if the coolant level changes in the hose. or the filler neck when you apply compressed air to the cylinder.   you have a leaking head gasket or cracked head..

as a side note.. i have also pulled the rocker arms on some .. let the compressed air move the piston to the bottom of the stroke..  and this checked the entire cylinder along with the head gasket.

why don't i use a cylinder leak down tester...

there is a small restriction in the end of the cylinder leak down tester hose.. preventing the full flow of air to really do this test.,,

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lately.. when ever i have a cylinder head off.. i have a stash of hylomar racing formula..  i coat both sides of the head gaskets just prior to installation..  just a thin coat..  let it hang for 20 minutes to let the solvents flash off.. so they don't damage the gasket materials..    i have had only one come back since 1993.. when i first started doing this.. and that was on a 22RE motor that needed the block surfaced as it had eaten away from the blown gasket between the cylinders.. it still lasted a month..

i have seen engine swaps that i had replaced the head gaskets on and resurfaced the heads.. that came back with steam pouring out from under the hood like a steam locomotive..   and the engine was NOT damaged..

its worth the 5 to 10 bucks for the hylomar... to prevent any chance of a leaking head gasket..


let me check into more info ..   now that i have put you to sleep...  

When the lower hose leaked i was only down about 1 gallon and i never noticed the temp gauge being high. But these engines have a hot spot on the heads under normal operating conditions. Thats what is causing the sludging because that hot spot is cooking the oil.So i gave it a good dose of Sea Foam and then i switched to Mobil 1 10w-30.  I think i might have the beginnings of a cylinder head issue along with a lot of other 4.7 Magnum owners. My friend spoke to several dealers about it and they act like they have never seen any such problem with the 4.7 but they are lying of coarse. I was also told the original style thermostat is not easy to get and the new doesnt seem to fit right. I was planning on testing my thermostat and drilling it tomorrow.  

hmm...  4.7 with head gasket problems...

http://www.denlorstools.com/autoblog/2009/12/misfire-and-coolant-loss-dodge-4-7-possible-head-gasket/


http://www.youtube.com/watch?feature=player_detailpage&v=3r_cWdF4YLw


i see a notch on the rubber gasket that might fit into a slot to align the thermostat???

 

After doing a little more research i'm beginning to wonder if it is air locked? Maybe thats why my temp drops after punching it around a sharp right turn. Either way i think i'm going to sell this  thing. I love the truck though so i will probably get an 06 or 07 with the 5.7.  

if you love the truck..  fix it.. drive it...  

head gaskets, new head bolts .. surfacing..  perhaps a valve job..  HYLOMAR..  perhaps new mopar exhaust bolts.. as i seem to recall there were problems..  

be sure that you PRESET The engine to TDC #1 before tear down..

you will also want to use the shop vacuum to vacuum out all the coolant from the engine..

Mobil 1 motor oil and filters..   cannot sludge up the engine..

you will get more for the truck if you want to sell it then as you have already fixed the problems..

did you check out the almost dozen truck magazines on this site..????

Truck Group
 4-Wheel & Off–Road
 4WD & Sport Utility
 Four Wheeler
 Jp Magazine
 Mini Truckin'
 Off–Road
 Sport Truck
 Truckin'
 RV Magazine
 8-Lug HD Truck  

Theres too many issues with the 4.7 i can probably get $15,000 to $16,000 right now as is. If i add $4000 to $5000 i can switch to a 2007 hemi with the same mileage.  

I dumped the 2006 4.7 and bought a 2010 Ram 1500 Quad Cab with a Hemi. Best move i could have made. I absolutely love the truck.  

ummm!!!!! HEMI.... wish i was there...