This, or can't he just pull the dipstick and check to see if his oil looks milky? Or is it more reliable to just drain a little bit out?

 

If there's no evidence of coolant in the oil (its really, really obvious usually), then perhaps you should have the compression checked on each of the cylinders to make sure your compression is good all the way around (determines bad rings or very small leaks into the water jackets) Take a good look at the spark plugs too when testing the compression look for fouling that could cause det or pre ignition. I am aware of, but not familiar with, a chemical that can be added to the coolant that will change colors (yellow i think) in the presence of exhaust gasses in the coolant. I've replaced 1 fan clutch/fan assy., 2 water pumps, 3 radiators, several T-stats and some of the freeze plugs on the 4.7 Rams so I am quite familiar with the cooling system. Check the fan first. With the engine off grab one of the fan blades and gently try to wiggle it back and forth if there is play then that's bad and the water pump bearing is going out and it will develop into a leak on the front of the engine dripping off of the crank pulley, The impeller is plastic so if thats eaten up the only way to tell is to remove the water pump and every thing else in the way. Check the freeze plugs they should be steel colored with no rust and no evidence of leaks around them there is plug on each head under the exh. manifold towards the front of the engine and I think four plugs on each side of the block and 2 in the back. with the engine cold try to get your hand back there to feel for moisture (you will likely have to remove the wheel and inner fender well to get the neccessary access to closely inspect the plugs. If the freeze plugs are all in good condition then you don't have to fight that disaster (impossible to replace the ones on the back without removing the engine). Check your thermostat by dropping it in a pot of boiling water it should open up. When you replaced the t-stat the 1st time what did the coolant look like (chunks of rust?) if yes, then that crap was moving thru the system and then was backflushed so possibly now some of the jackets may have become clogged or partially clogged with that junk. Did you replace the coolant with Mopar or equivalent? and finally I've seen the 4.7 pretend like the air was completely purged from the system before and then sure enough boom hot right away with a lil bit of driving I would double check that the system is air-free and builds pressure, make sure the heater is on and set to high, squeeze the hoses to make sure the air is out and let the engine idle for a long time with the cap off (at least to operating temperature and check for a drop in fluid level in the resivior) if I'm thinking right there is a small hose that connects from the rad to the pressurized resivior and also 1 larger hose from the back of the resivior intercepting one of the heater hoses behind and below, if so then yes there should be a jet of water from the smaller hose into the resivior regardless of temp. There is some pretty good info on purging the cooling system on here find it (DIY section?) and make sure you followed it to the letter. I know how irritating a cooling system can be. Oh and nothing beats good maintenance in that area, was the system flushed, filled and inspected (by you, a shop, a dealer, whatever) at the regular maintenance intervals or close to them?

On another note, I never really heard before that the head gaskets were weak on the 4.7s I thought they were laminated 3 layer steel and pretty stout can someone point me to a thread about that?

 

Search for threads by me a few weeks ago and people were talking about it in there. I would find it for you but I am walking out the door to get to work. Sorry man, but yeah everyone told me that 4.7s are known to do this crap lol

 

Thanks Ice,

Did not know that bout the head gaskets.

 

There was a thread on another forum w/ very similar symptoms as your's and it turned out to be a clogged radiator. The guy said his truck would not overheat at idle but would overheat going down the road, but his radiator was relatively cool all over. Here is the thread location http://www."".com/forums/showthread.php?t=258946 just delete the quotes and put "dodge talk" w/o a space in their place.

 

The CEL is on...

I am not losing any coolant...it stays at a constant level as far as I can tell.

I live in Dallas too, so yeah, I know about the mild temp days we have....although this weekend was not too bad.

When I installed the thermostat, the coolant that came out was NASTY. and when I say nasty, I mean it. Brown, with rusty chunks in it. In fact, I tried flushing the radiator by removing the drain plug and nothing came out. So I stuck the water hose in the upper opeing and just kept running water through the radiator until there was a flow from the drain plug. I thought I might have gotten it all out....

I bought the truck used about 8K miles ago. So I am not sure what maintenance work was done to it. I did replace the air filter, and changed the oil as soon as I got it. But I have not done much else. I usually drive it to Home Depot and to the lake. So I've only put 8K in the last 18 months.

One thing I did just learn, when I was looking for air pockets in the cooling system, I did not have the heater on...and maybe, just maybe there was air in the heating coil. I am going to recheck for air pockets when I get home...will let you know.

Ok, when I drain the oil to detect for coolant, I should run the car first or do it cold?

 

What's the code? You might be able to get a code doing the key trick, here are the steps:
1. w/ engine off turn key to "run"
2. turn key to "off"
3. turn to "run"
4. turn to "off"
5. turn to "run" (all of these key turns should be done in about 5 seconds)
6. odometer shows codes or "done"
Otherwise go to somewhere like autozone and have them pull the code.

 

Yeah, hopefully it's just something minor. I was just saying it sounds almost IDENTICAL to what was happening to me and letting him kno what it could mean and that he should prob stop driving it until he figures it out. =\

 

I have to get in on this thread since I am having nearly the same issue.
'02 1500 56k.
I found out about the rad cap thing and changed it. Themostat was done in October. Bled the air out of cooling system using the "Coolant Bleed" Plug at the top of the engine where the upper rad hose attaches.
I can drive around town and the temp gauge doesn't get higher than half. But when I take it up a twisty uphill road, it jumps to about 2/3, even higher. Turn around and come back down, temp comes down only a bit. I get into my driveway and the upper hose is firm and hot. Lower hose is firm, but not as hot. The cap would be cool enough leave your hand on it.
I am one of those guys that has a hard time believing that my water pump would go with such little mileage. The shaft has no play and there is no drainage from the weep hole. (which doesn't necessarily mean it isn't bad)
I have found one other thread that a forum member solved his similar issue by changing his fan clutch, Even though the part didn't seem faulty. Search "may need new radiator" for that thread. Fan clutch....I think that's where I'm going next.
BTW Roarky... I should hope I get to 120k !!

 

I bet your radiator is still clogged. A reverse flush of the radiator may clean it out and solve your overheating problems, but IMO a new radiator is the smartest move for long term reliability.