2004 Durango

andy

I have an '04 4.7L Durango with 40K miles.  Last week, as I was going up a steep grade, I noticed the temp gauge move to just below 3/4.  Going down the other side of the grade, the temp goes back to normal.  At highway speed, temps are fine.  When sitting still, temps go back up.  It's worse with AC on.

I am the 2nd owner of this Durango, bought it with 12K miles.  Coolant levels are fine.  Did an oil change, nothing strange in the oil.

The problem is at it's worst when climbing hills, especially with AC on.  I do not 'flog it' going up hills, maybe 40-45MPH.

Coolant is the orange stuff, and looks fine.

With only 40K miles, is a clogged rad likely?  Is fan-clutch more likely?  Temps are fine at highway speeds...it just does not like climbing hills or sitting still.  This makes me think air-flow.

I do not want to start throwing money and parts at this thing to fix it.  Local rad shop wants to 'rod the rad and replace t-stat'.  Should I do a fan clutch myself first?

Things I don't want to do on my own....replace rad or water pump.  I really have my doubts about a clogged rad or bad pump at 40K miles, but then again...that's why I came here.  

Any help you can provide will be appreciated.

.Sounds like maybe your fan isn't working...

.Main fan or the electric fan?  Isn't the electric fan just for the A/C core?

.The electric one is for the A/C and as a backup to the belt driven fan.

Can you wiggle the clutch fan back and forth any? It shouldn't move more than maybe 1/16quot; at the blades.

.The fan clutch has almost no play.  The AC fan is coming on when I have the AC on, so that seems normal.  I can move the main fan blades by hand, but they do not spin freely.  I can not get 3/4 rotation out of them by giving them a quick spin by hand.  Should I be able to spin the fan blades a full rotation or more with a quick finger flick?

.the fan blade should only turn 3/4 to 1 turn. check tstat,pump,and cap.

.How do you check the water pump, t-stat, and cap without replacing them?

.Start with the easy stuff, wash out your condensor and Radiator, make sure there's nothing stuck between them, depending on what enviroment  your run your vehicle in you get stuff building up between them sometimes.

.Just so I understand, I need to replace:

Water Pump
Thermostat
Fan Clutch
Radiator Cap

Is this correct?

.I'd first try to flush the system out and refill with new coolant. 50/50 mix at most.

Make sure that the rad/condenser aren't plugged with debris, that makes a hell of a difference.

If that doesn't go it, replacing the t-stat and waterpump would be a good next step. You can drain the coolant into a clean bucket to reuse.

.Your symptons make no sense. While pulling a grade and the temp goes up but then comes back down under normal driving indicates either low coolant level or plugged radiator. Temp climbing while sitting still is either an airflow problem through the radiator or low coolant level. A bad t-stat usually overhaeats all the time adn unless your water pump has play in the bearing or is physically leaking it ain't bad. How did you check the coolant level. You should let the vehicle sit overnight and then check the level in both the overflow tank and also in the upper hose.

.To check the coolant level, I removed the rad cap after the truck has sat over night.  The coolant is up to the level of the plunger under the rad cap.  The overflow jug is also 3/4 full of coolant.

Being that my symptoms don't make sense, does that mean I have to start throwing parts and money at it until it's fixed?  Should I trade it in on a Nissan Armada?

I am starting to understand why Chrysler went under.

.Overheating happens to every vehicle out there...just a matter of time. If the vehicle is at idle and overheats just sitting there and you can feel air being sucked in through the front of the truck( take a rag and hold it in front of the grille, if it gets sucked in and held there the fan is ok) then I would put a t-stat in it. A plugged radiator usually overheats at freeway speeds or while pulling a steep grade but will cool down after idling for a while unless it is extremely plugged. Given the amount of miles and the year of your DUR I wouldn't suspect a plugged radiator but anything is possible...for the record you don't want to know how many radiators I have put in Armadas...what a waste of a vehicle

.Ok, here is my plan.  Let me know if it makes sense...

Drain rad and use some type of rad flush chemical.

What type works?  Does any of the quot;off the shelfquot; rad flush work?

Replace thermostat.

Refill rad with new coolant.

If problem persists, change fan clutch.

Am I missing anything?

.Sounds like a good plan. You can get a kit to flush the radiator off the shelf. I would be surprised if a flush and stat don't fix it though...