Hello,

Just picked up a Dakota, and I have an issue with it on my first drive. Conditions of the drive, pulling a ultra light (2500 lbs dry), hot day (95) and fair amount of hills for the drive.

I notice the heat is going from 1/2 to 3/4 on good hills, which settles back down to 1/2 mark on the downhill side. I don't take to much note since I am pulling.

At one point, 30 minutes into the drive. I'm going downhill. I put the OD on for a moment (just out of curiosity) and I noticed as the same time the heat gauge shoot up to the red (the start of the check engine light) and settle back down rather quickly after I put the OD back off quickly after. Was this coincidence, not sure.

I'm a little worried about it, but I keep going. I hit a town about 1 hour in. I slow down to about city speed, and suddenly my heat gauge darts into the red, top of the mark. So I pull over about 30 seconds later. Turn it off, wait 15 minutes.

Notice the level is now a little below the red. So I try to start it, but its runs like a dog and quits (about 5 secs), try again, same. Wait another 15 minutes. Same result. Wait another 15 minutes, runs like a dog but stays running. 20 Seconds later, she smooths out into a regular idle. Turn it off as I can see the heat going back up quickly.

Now I go over and let out the rad cap (slowly), I notice the coolant reservoir is full as well. I start the truck to see if there was any air bubbles and if the coolant is moving (no signs of any leaks or coolant). Cap it back up. So I head back home (not worth testing for another 3 hours) and it runs from the 1/4 to 1/2 mark now. No overheat.

No sign of coolant in Oil, or smoke. I returned a week later to start the truck, no problems, and no smoke, but also no coolant in the coolant reservoir, and empty when I take the cap off (while cold)

Opinions? I was thinking of getting a block tester for the coolant. Test for a Gasket Issue. Could it have been as easy as an air bubble? I can see the that Water pump, Upper Rad Hose (20lbs cap looks new), Clutch Fan have all been done. Fans all work as they should to the best of my knowledge.

 

Welcome to the forum Patch!

Did you hear the clutch fan "roaring" when you got hot? It should. Bleeding the 4.7 isn't that difficult but it does need to be done. If the work was recent maybe there was air in it. You could also have a sticking/slow thermostat.

Don't rely on the looks of the cap. Test it.

Do you have the tow package? There should be a transmission cooler in front of the condenser.

The head gaskets are a possibility as well if the truck ever got hot.

Finally, don't use O/D when towing on hills. Let the engine rev a bit.

 

2500 pound trailer is not "ultra light" for our trucks. That's what our car hauler weighed empty and I could only drive in first and second gear with the V6, it just could not carry 3rd gear even with 4.10 gears. If you have the 4.7 you probably have 3.55 gear, which is definitely not a towing gear. There's also the 3.23 rear gear option but I don't think it was used often.

Here's my opinion:

It sounds like your heat was running invert proportionally to water pump speed, so it's not the water pump. I think that one or both of your fans are not working, so the only cooling you were getting was parasitic off of the movement of the truck. high RPM + moving quickly = low temps. low RPM + moving slowly = high temps. Electric fan if equipped should come on around 205-210 degrees, clutch fan should sound like a 787 dreamliner taking off around 190-200 degrees.

 

Thx for the reply. I went and got a coolant completely removed and replaced, and drove the snot out of it today, and no problems at all. Drove up steep uphill with high RPM, and AC a blasting nothing. Stuck around the 1/4 mark. No load though, and its not a hot day.
Although, I noticed that the coolant has a some particles in it (rust I'm guessing)

It is the V8 yes, it should be able to tow 2500lbs plus some cargo no?

Tranny cooler yes. Factory Tow Package.

I know that I can't use OD when towing. I just wanted to see what would happen going downhill for a second. The Temp gauge doesn't read into the Tranny does it?

I know for sure that the fan comes on, now weather the clutch fan did or not I don't know for sure. Sorry, I'm not to familiar.

I thought about the T-stat getting sticky and perhaps not opening. Wish I had felt the lower hose to find out.

I'm thinking of reselling it, and getting a full size instead. I used to have a 2004 F150, and it towed like a dream. I also have a 2011 (with the 3.6L) Caravan that Tows just as well as the Dakota does (yes, it has a Tranny Cooler) but I don't like towing that much weight with it even though its capable of doing so. If I do, I take it on flat roads and short distances.

 

No, the temp gauge doesn't read the tranny temp. If the tranny fluid is running though the radiators internal transmission oil cooler portion, having a 5 speed I'm not sure how it's plumbed with the external cooler, then the fluid can contribute to it running hot.

I'm thinking more along the lines of a "sluggish" thermostat versus sticking.

Magnets description of the clutch fan is spot on. It WILL sound like a large jet engine taking off when the clutch engages. If you don't hear it, and feel it in the pedal - it's a big drag, it isn't working.

 

Be able to tow 2500 + cargo? Sure. Throw 4.10's in it and can probably tow 3500-4000 and another 800 in the bed.

Here's the thing to think about. Brakes and weight distribution.

The dakota is roughly a 4000-4200 pound truck at the scales. Quad cab maybe 4500-4700. A full size truck is closer to 5500-6000 pounds. The weight difference is in the frame rail size and cab height (and length). I think our frame rails are 6x1.5 or 2" thin wall (1/4" MAYBE) and a ram 1500 is closer to 8" x 2 or 2.5" thick wall (3/8"). I'd have to go outside and measure.

With the dakota, you have a trailer half the weight of the truck trying to swing it's weight around and push you. Without trailer brakes, our empty car hauler would and did push me right through several red lights even with the e-brake on the floor and both feet on the brake pedal and no wheel lockup- simply too much rear weight to allow it. The trailer just pushed me through the brakes. I just learned to slow down approaching intersections (even if green light) and towed in 2nd gear and was ready to pull 1st if I needed to engine brake.

A full size truck is 3x the trailer weight plus has bigger brakes and bigger tires and can simply handle the load better.

 

Thx for the feedback.

Put it up for sale this afternoon, going to search out a bigger truck. I think the issue was a sticky T-stat. Truck feels fine now ...


The e-brakes on my trailer are crazy strong. It pulls my van backwards if I'm not careful (have to pump n watch how I brake). The Dakota felt a lot better with the way it braked, but you have to push hard for the brakes to work on that thing.

 

Not wanting to take this thread sideways but this reminds me of when a family member borrowed my truck to haul a heavy load in the bed. He commented on how hard he would have to push the brake to stop. One of the first things I did upon buying this truck, was flush/bleed out the brake fluid and replace with fresh with Valvoline Dot 3 and 4. I also replaced the front rotors. Just wondering if not having the brakes bled using the DRB scan tool might be the issue. Normal driving, the brakes feel okay but of course I press them harder than say, my Accord. It's a truck. I just don't know how comfy I would feel towing a large load.

 

I'm the opposite. I deck the brakes and it goes 3/4 to the floor then gets hard and tries to lock up.

 

Drove around for 2 hours today in town doing errands, and no further issues. Stayed right at the 1/4 mark.

I noticed that the OverFlow was leaking out a bit of coolant, but I believe that's cause the Oil place overfilled the reservoir to the top of the neck. I also noticed the cap relieving a tiny bit of air after a long driving and air bubbles from the reservoir as well after I stopped the truck (only did it for a few seconds then stopped)

I ended up pulling 1.5L of coolant out so it was at the Full Level instead. I'll recheck tomorrow.