Hello all,

Long post here but thought some background was needed on my issue:

Last Thursday my daughter was driving my 2001 Durango (4.7L SLT 4x) and the upper radiator hose blew just on the radiator side of the cap. Fortunately she pulled over immediately and called for help...hitched a ride to her location with my mom and found the hose blown...no biggie...off to Autozone for a replacement part (Dayco Hose Upper part #D72447)
(had to cut it a tad to properly fit)

I of course fought with the blanking factory style clamp where the hose connects to the engine (and replaced it with a regular hose clamp) filled it back up and tried to burp it through the filler opening...all seemed good...so off to the gas station (was on fumes which is why she was heading to town in the first place and almost immediately it started running hot...even with the heater on full bore trying to circulate as much as possible...I limped it to the station, it never got "too" hot and topped off the coolant reservoir again...made it to the car wash, cleaned off all the nasty antifreeze, checked the levels and limped her home. Still ran hotter than usual. So I let it sit and fully cool and then proceeded to try and burp it again...thought it was all good, she drove it the next day and no issues until my folks loaded up to bring it home to me in Reno...they made it about 2 miles and it was HOT. Dad opened the hood and it seemed the cap on the upper hose was leaking...it actually blew off in his face...luckily no serious injuries...had the beast towed home and decided to replace the upper hose again thinking it was a bad cap assembly. I also had my mechanic friend check to see if there was any exhaust in the coolant and his tester did not indicate any. I preceded to replace the t-stat as well...I also flushed clean water though the radiator and the block all seemed well at the time. buttoned it all up and filled and started the burping process again...still having issue with it getting hot again...I am on my second cool down cycle and am at a loss....I did not see any signs of bad water pump, no excessive play in the bearings, coolant reservoir line is clear, what else am I missing??? any suggestions would be greatly appreciated.

As a side note, I had my transmission replaced a few weeks ago and had to burp the system at that time and accomplished it by opening the filler cap starting it, and adding coolant and water mixture while it bubbled up...after that it was great until the line blew...did I do it wrong????

Thanks again for taking the time to read this rambling request for help

Steve

***Should have titled it overheating issues lol ****

 

the 4.7 also has a bleeder valve where the hot line comes out of the block that you can use to help with bleeding issues.

I wonder if the radiator is flowing properly if its still overheating, a clog in the radiator could have been part of the original problem with the pressure getting too high and blowing the upper hose.

p.s. i hope you replaced the lower hose too at this point. the hoses tend to go pretty close together.

 

When you said that the 4.7 also has a bleeder valve are you talking about the hex head screw where the upper hose connects or someplace else?? I have filled the system up, got it to a "normal" temp, let it cool, opened up that hex screw and had water coming out of it. I tightened it back down, started the engine with the filler cap off the hose and made sure it was topped off...let it sit and repeated like 2x more...drove it for about 10 min and it got hot again...having my mechanic take a look at it tomorrow..I surrender on this one Also, I did not replace the lower one as it looked almost brand new...

Another thought just popped into my mind...on the original hose, there was an internal spring it in...the 2 replacements did not come with them...when I asked the autozone dude about it he said it wasn't required...should that have been put back in ??? Not sure what that would do to cause it to over heat but I am grasping at straws here...

 

Well, finally discovered the issue. The water pump had failed. The impeller would turn barely when the pulley was spun. Replaced it and went to a fail safe t-stat and she is once again happily purring down the road. Thanks everyone for helping out.

 

not sure but my wifes 03 durango 4.7 fan clutch went out , change and it has to be cooling every thing better !!!!!