I recently bought my durango, and I love it. It runs great, but it has had it's share of neglect from previous owners. So I am trying to fix things here and there as I go. One of the issues is that it has a tendency to overheat if you sit idling in one spot for an extended period of time. Like waiting for a buddy at the end of main street during Daytona Bike Week for like 20 minutes. Also, I am going to replace the plenum gaskets with the kit everyone here talks about from Hughes. And it has a transmission fluid leak. A check engine scan revealed a "massive vacuum leak" and a "misfire in cylinder 5".... I know I said it runs great, and despite these issues, it really does run great.
So, on to my question. I read all about step by step how to do the plenum repair on the hughes website (great article), and when I got home, I popped the hood just to look at the motor.. I determined that I don't need to remove the fan shroud and coolant bottle (as per the write up) because the durango engine compartment is too small to step inside anyway), so that will save a little time. HOWEVER, while I had the hood open, I noticed that there is a metal tube stickingout of the top of my water pump on the driver's side that has a 3/4 inch or so hose clamped to it that goes back towards the firewall.... Not sure if it's a heater hose, or bypass hose or what...... BUT, it's leaking around where the hose clamps to the metal tube AND it's leaking where the metal tube goes into the water pump.... This may partially explain the overheating issue. What is the tube, what is the hose, and how do I fix this??? Is there a seal or something inside there? Thanks

 

a picture of the hose you are looking at would be helpful, or you can check the service manual http://www.mediafire.com/?xu9h0gt9bdcn6

 

The tube is the outlet from the water pump. It has only 1 bolt that holds it down below on a holding rod. What you do is remove the clamp and hose, then remove the bolt holding the tube on down below. Now just slightly pull straight out and kinda turn a little to help it out of the water pump as it just sits down in there. There is a small O ring where it plugs into the water pump. This O ring is worn or deteriorated. Take it to the auto parts store and get a new O ring.

Now place a very small amount of gasket sealant to the new O ring which on the tube and slowly rotate it back down into the water pump and install the bolt holding it in place. This is going to not look right but it is!

Now the hose;

That hose is the HOT pressure hose and the correct name is the Heater Hose. It is a 5/8 heater core hose if I remember right. Take it in to the parts store and just get some regular heater hose and they will match it up for you including length. Get 2 new Worm Clamps for the new heater hose (one for each side).

The nipple hanging out of the fire wall is your heater core.

The other Heater Hose is just to the passenger side (left) of the entrance of the pressure line on the Heater Core. This hose is the cold side that is returning to the motor. It returns into the intake manifold.

The Bypass Hose is directly on top of the water pump and is only like 3 inch's long. It goes between the Water Pump and the intake manifold.


Yes it is most likely your issue with heating up. The other thing you need to understand is the 1998-1999 Durango's did not come with a auxiliary electric fan so the only fan you have is the motor. It can and will heat up so be careful.

 

Also for the Plen. gasket. You'll want to remove your belt and there will be a few things and that bracket in the way to take off the intake manifold. So you'll need an intake mani gask. too. For the over heating part. I had this well sort of as I never went over 230 ish roughly but the same symptoms and I disconnected both heater hoses and hooked up a water hose and flushed the heater core. Then I hooked it all back up and flushed the rest of the system. I too have a great D but it went unmaintained. She's getting ready to have a rebuilt engine in it soon. By soon next Summer it's a personal pref as there is only120k on it. With the coolant flush I never get to 210 straight up now. I tried even.

 

thanks for the answers.... I am out there right now messing with it. I appreciate the help.

 

It's a good ideal if you plan on keeping your D to get a Childers book on it to assist when needed too. They run 15-20 dollars.