I have the 2000 durango 4.7, and I would like to know if there's quick way to check if it's stuck open. I'm not too good with the cooling system, is there supposed to be coolant flowing through the upper radiator hose constantly? I start the engine cold and that's coolant moving through it. Or should I check the lower hose? I'd it helps it takes about 20 minutes for it start blowing hot air too. Even then it's just Luke-warm. Don't know if there's a problem with the heater core too. Thanks in advance

 

That's the quickest way I know of other than pulling it out!

No, the upper radiator hose should take a few minutes to heat up since your thermostat should not open up and let the coolant flow out of the engine until it reaches it's rated temp. i.e. 185 degrees.

 

1) 4.7 has a 195degree t-stat not 185, however they flow will being to show up at lower temperatures since the stat is fully open at 195 not starting to open.

2) the stat in 4.7 is located in the lower hose, and has a weep hole in it, it will allow some small amount of flow even w/ the stat fully closed, however it should not be significant and i would not expect it to be noticable

 

Yeah, it's a noticeable amount I can feel flowing through the hose. I'm pretty sure the thermostat is the problem. Once the starter gets nicer it's getting replaced. And so I have to drain the coolant to change the thermostat?

 

yes you do. since its lower rad hose in the block. theres a *** on the sid eof the radiator that you turn and itll drain. though mine was clogged or soemthing so we just had to deal with popping the lower rad hose and do things the messy way

 

Damn, hate to say this but I wish it was like a Ford with the thermostat in the upper hose haha. So far dodge has been the most inconvenient and pain in the *** to work on. Thanks for the replies guys

 

the 5.2 and 5.9 have the stat in the upper hose, not sure why they put it in the lower on the 4.7

 

Yeah. I'm not really a fan of the 4.7. Now I have a dumb question, when filling the empty coolant, do you take off the radiator cap and fill it from there or fill the reservoir? As I said this is the first time I've ever dealt with the cooling system so I'm not too familiar with it

 

you have to do both, fill it through the cap as best you can, and then fill the reservoir, what happens is air gets stuck in the system and it will bleed out into the tank as the coolant expands and then there needs to be coolant in there to draw back in or else you get permanent air pockets

p.s. make sure you burp the system correctly or else you WILL overheat the truck

 

on the 4.7 where the upper hose is on the engine block where a theremostat SHOULD be. youll see an allen head screw take it out after filling coolant and run the truck any air will come out though there.