Hello all,
New to forum, just posted it in the noob section.. But I need some help and Im hoping you guys can help me out.. Im gonna kind of C/P what im gonna ask from another forum I posted this at, [H]. Some of the stuff in the beginning has already been fixed, but I want to give you the whole story..

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I have a 2002 Durango SXT 4.7L V8 Mag


Back a few months ago it had a leak in the Radiator hose so I replaced it, has been running good.. A few weeks ago it starting idling really high so I ran B12 thru the fuel system and gunned it around and now it working fine.. Went to run some errands today, total trip about 5 miles and on my way back my Check Gauges light came on and my truck was on the verge of overheating so I turned the heater on full blast and it was still goin up so I pulled over and let it cool down for about 20 minutes.. (Its about 65f out and 10mph wind)..

Checked my guages again and it had cooled down to normal range so I fire my truck up and kept going.. got about 1 mile before it almost overheated again so pulled over again.. sat for 20 minutes, popped my hood and let my truck idle for about 5 minutes and the temp got cooler when it idled but once I started moving it shot back up really quick again,,,

**They suggested replacing the Thermostat**

nope, no leaks found, checked hoses for signs of sucking closed, nuthin.. Went ahead and replaced the Thermostat, gave it an oil change, cleaned my K&N, and cleaned out the throttle body...

Not overheating now, but still running a little hotter than id like... Gonna keep an eye on it and see what happens..


**High idle issue resolved**

Test Drive #1 - Sunday Night
As far as the heat gauge, this is kinda where its at after 10 minutes of street then highway driving..


C|__|________||______X__|__|H


**Monday**

Got the thermostat installed, got the radiator topped off at like 2:30am this morning.. and then apparently didnt screw the cap on all the way tight.. So I leave for work at about 3PM, I got to the post office and it was running really hot (Same route as the 10min test drive).. let it sit for a minute, snugged the cap on and it made it all the way to work (35 minutes) stayed stable at where I showed the last mark.. After lunch I re-topped off the tank from what has sprayed out, made sure cap was on tight.. At 11:45pm I left for home and it almost overheated 5 minutes into the trip.. Kept on the hazards and leapfrogged down the highway.. wasnt too bad since its almost 1230am.. Found out that if I take side roads and keep it under 30 I never gets to the danger zone so I just slowly crawled down back roads to get home.. So here are my questions..


1) It seemed fixed cept for my retardedness with the cap, and then got worse after work.. Is it possible for air bubbles to get sucked into the radiator with the cap not on completely tight?

2) Think I may have gotten a bad thermostat?

3) Person on other forum mentioned head gasket could be the issue.. Confirm?

I checked my hoses after the first time it almost overheated on the way home from work and I didnt see any fresh leaks on the upper or lower hose.. This is a new radiator and its only ever had water and orange stuff in it, nothing foreign..Ive never replaced a head gasket like mentioned before.. I know just enough about car to get me by but can do any work im guided thru..





Thats pretty much all the info I have, can get more if needed.. I have less than 150$ to spend on parts and have to do all the work myself.. I have most every tool required to fix just about everything on here, but anything I do needs to be able to take a noob less than a day.. I live at an apartment complex and they dont like broken down cars there for more than a day.. no garage to work in, all are hand tools.. BTW, like I said earlier, car heats up quickly, but cools down faster when I parked and idle than actually shutting it off..

 

Read my thread on Virginia-Minnneapolis bound and this may provide some insight.

If you take nothing away from the thread then take this.

DO NOT USE PEPBOYS!!!

 

Thnx for the reply, Gonna link to thread and quote reference here..

Link to Thread

Aside from a full flush is there any other way to work it out IF its an air bubble?

 

Correct, that was the beginning of the thread and at that time everything was good. Fast forward a week and still the same problem. Add in a block test/pressure test then the next day add a fan clutch and thermostat. Fast forward another 24 hours and add in a waterpump then a week later the radiator. One thing to be thankful for is that I got the gauge cluster instead of the idiot light, by the time that light came on the more serious damage would probably have been done.

Obviously I can't force you where to take it for maintenance but I would strongly recommend against P/B and if you do take it there....watch them like a hawk and ask for old parts back for independent inspection. In my case they just threw parts at the symptom without solving the problem, infact most likely made the problem worse by the false sense of security.

 

As for the air buubble, I cant think of anything but a flush also remember this engine cooling works opposite of most engines or at least anything I have ever worked on or learned about before. The upper hose is FROM engine -Radiator everything I have ever learned before, the upperhose is TO the engine.

 

You may want to make sure the hoses are in good shape. It may be possible one of the hoses, possibly the lower hose that may be collapsing when you are running on the road that can cause restriction, thus, overheating.

 

in response to getting air in the system, yes it is possible, and there is a procedure to burp the engine, but idk what it is offhand, it is on here somewhere just do a quick search for it

 

Yeah, I kinda did the burp once already, but ill give it another shot.. Like I said before, I didnt see any evidence of collapsing hoses, all of mine are pretty sturdy..

And yes, I avoid Pep Boys and FireStone like the plague.. I prefer to get on craigslist and find the first off-duty mechanic trying to make money on the side and help them out..


edit:

Oh, and heres some linkage on how to burp your cooling system..

 

i think its a little bit different on the 4.7l for some reason somone on here has done it (i cant remember who, or when) and i was hoping he would post up for you, but you should definetly try burping the system

 

Well, I went ahead and did the burp tonight, and it seemed to work.. Let car run for about 30 minutes with the cap off, had to rerfill the res once while it was running.. After about the 20 minute mark once it finally got warm I hit the AC for the extra RPM's, once I did that it bubbled out a lot.. Flipped the AC on and off every couple minutes till it stopped bubbling.. Not gonna get a chance to drive it till tomorrow morning hopefully.. but im gonna let it cool off for a few minutes and then put the cap back on..

Ill let you guys know how it turns out..