I have a 2001 Durango 4.7L 4x4 SLT that recently overheated a little bit on the highway. I pulled off at the next exit (the coolant temp gauge never rose above the 3/4 mark). After it cooled off, I checked it out and the coolant had been coming out of the overflow tank. It didn't lose much coolant (I could still see plenty of fluid below the cap) and while it was cooled, I drove it home. I took the cap up to O'reilly's and had it checked. It failed each of three tests so I replaced it with a 21 PSI. No more coolant from the overflow. Water pump is working. Clutch fan is working. Efan is working too. After filling up a little more coolant and per the process on this forum burping the system, it still gets hot. I did have tiny bubbles in the bleed hole during the burping process - they never did completely stop. It also looks like very light traces of steam from the tailpipe during idle. I had a block test performed and it passed, but I have heard that it can still pass but have a blown head gasket or hairline crack in the head(s).

Anything else that I could do to narrow this down?

Thanks,
Brian

 

SOunds like a lot of the classic symptoms of my RADIATOR FAIL from last October.

1. DO NOT TAKE THE VEHICLE TO PEPBOYS.

2. With #1 said, have radiator checked. Get professionally checked, using a digital thermometer, my final dealer repair found hot/cold spots in the radiator.

Looking at the radiator from the engine side, look through water pump and fan, look at fins/cores look for expansion, splits, get a good flash/work light.

Do not rule out the other side, but that might will be more detailed, and difficult to see but a good light will make it easier.

Basically when the coolant doesn't cycle through the radiator, it eventually has to vent somewhere which is overboard.

Ironically my radiator failed about 6 months to the day AFTER A water pump, thermostat, Upper and Lower hose removal/replacement AND a total block and system flush.

 

I just had the radiator (back)flushed and a new thermostat installed. Still overheats at 70MPH on the highway. The shop said that the coolant and previous thermostat were trash.

Here's the part I cannot clearly understand what this symptom is from:

They measured the temperature at the thermostat while idle and warmed up. It was right at 195 degrees but the scan tool said that the PCM was reading a 225 degree at the coolant temp sensor, the gauge was almost exactly in the center of the sweep and the e-fan was on. They pressure tested the cooling system, tested the clutch fan and said that they are in great shape - no head gasket issue. Any ideas? They want to replace the water pump. I wonder if it could be the radiator. Not sure, but very frustrated and obviously do not want to spend more than I have to.

By the way - thank you Magic for your previous comment and thank you to anyone willing to offer any input.

Brian

 

what about a collapsing radiator hose? u check for this? i have seen several people go threw all kinds of trouble replacing expensive parts just to find out hose was collapsing. Are u positive u burped it correctly? these things can be a pain to burp. Did u use the proper thermostat? one with a weep hole?

 

see that little hole near the top? not all aftermarket ones have that hole.. some do not have an issue but some do an need that hole

 

Replace the coolant sending sensor!


Next do a cluster reset to see if your gauge is reading correctly. https://dodgeforum.com/forum/1st-gen...ml#post2136829

 

Not sure about the hoses and collapsing. The top hose is bulging a little on both sides of the filler neck. Could I check this by revving the engine when it is warm? I know that the t-stat is like the one in the picture. I will double check the burping.

Is it possible that the coolant temperature sensor could actually cause the overheat or prevent the system from cooling adequately? When it overheats, is seems almost like a tipping point - when it starts to get hot, it just keeps getting hotter until I shut it down or run the front and back heater's at maximum for 15 or 20 minutes. Running the AC on the highway will cause it to overheat every time. With respect to coolant flow; Is the water pump between the coolant temp sensor and the thermostat?

Thanks,
Brian

 

is it actually overheating, or is the gauge in the truck claiming that it is overheating? get a wireless (infrared or similar) non contact thermometer and check the hose temps ect next time that the gauge claims it is overheating, if the thermometer says no, then it is most likely just the temp sending unit going bad

 

^^Ummm... A bit late, there shrps dude.

 

I just did what you said here and the temp at the thermostat housing is 203 and the temp at the top coolant housing just before the hoses is 216. The gauge in cluster is reading just under 3/4.