Hey all, glad to have finally found a good Durango-specific forum

Here's my issue:

I have a '98 Durango 5.2 liter/318, mostly stock. For the past month or so, it's started overheating badly, especially in heavy traffic/start-n-stop travelling. The symptoms have been numerous, and seem to fluctuate, but the outcome is the same: Almost complete redline after about 10 minutes. If I start it up and idle it without driving anywhere, its fine. I could leave it for an hour, no problem. If I start it up dead cold and try driving it, the engine runs higher than normal, and in both first and second gear it moves sluggish while the engine seems to be revving high, then in third gear, or after its heated upafter a few minutes, it drives fine. Running the heater to bleed off the heat helps, but doesn't control it unless I'm driving on open road, doing around 65mph. Anything under 55, or over 70 and the temp starts to go back up. Before the overheating problem, it would never get above 185 on the temp guage. Now, it will creep up to 210 after a few minutes, and from there its a downhill race until I can get somewhere safe to park it to cool down.

My father and brother both have about 60 years combined ASE-certified mechanic experience under their belts, and even they are almost out of options. Here's a list of what all we've tried:

Initial maintenance when it first started overheating:
1. replace plugs
2. change engine oil and filter
3. replace serpentine belt, air filter
4. fluid check/refill (standard stuff)
5. bottle of Lucas in both the engine oil and transmission

When that didn't solve anything, other than a few extra mpg, Round 2:
6. replaced fan clutch
7. replaced thermostat (192, non failsafe)
8. complete drain/flush of cooling system, refilled with 50/50
9. checked for leaks (none)

Round 3:
10. thorough hose check for collapsed sections, wear etc
11. replaced water pump
12. replaced thermostat (again), this time with a 180 failsafe
13. transmission fluid/filter change. No shavings, oil was mostly clear.
14. second backflushing, with Prestone Superflush and Anti-rust. Flushed both top down, and from bottom up. No blockage.
15. auxiliary tranny oil cooler installed.

Round 4 (pending):
16. Take out to field somewhere, cover in gasoline and "accidentally" set it ablaze

Nothing's worked so far. The only things left I can think to do/plan on getting checked are:
1. timing check
2. compression check for blown head gasket/warped head
3. pressure test on cooling system
4. get the radiator cored out
5. replace radiator altogether
6. replace cat converter
7. replace heater core
8. rebuild transmission

That's about as thorough as I can be. The engine hasn't really been bogging down, maybe a slight loss of power but I can't be totally sure. There's no water in the oil/oil in the water to indicate a head gasket problem, yet I have noticed a bit of moisture out of the tailpipe, with the occasional drop of water beading at the end. No full on spray tho. I have this sneaky suspicion its something thats so remote of a possibility, so obscure that it happens in one in every 500 cars. I'm open to ANY suggestions/ideas you all might have. Thanks in advance!

 

I Would probably would start with a pressure test, if your losing water out your exhaust side your not gonna see any water in your oil, not until it fully blows anyways, thats been my experiences in the past.

 

I've got some cheap solutions.

1. Pull the trany filter and FULLY clean out the pan and replace the filter. I've had these same issues and this was all it was. The trans fluid was heating up because of some blockage and rolling into the radiator cooler and overheating the motor. Remember that oil's take a lot longer to cool then antifreeze! Also remember to only put the right fluid into your trans. Check the owners manual.

2. Do a back pressure test on the cat. Most muffler shops will do this for free and you shouln't have more than 5 Lbs. back pressure. If needed get a hi-flow cat (trust me)

Try these first and formost. Get back to us and tell us soome good news.

 

I suggest that you clean the A/C condensor (which is the radiator at the front, the one for the engine is behind it) by pressure washing. If it's blocked then not enough air will be drawn through to cool the engine - Durango's are very sensitive to this. If you have an electric cooling fan then check all the snap connectors to ensure that they are not shorting or burning out - it was only when mine blew like a fuse in a plug that I realised that the cooling problem was all due to it acting like a little resistor.

If you don't have an electric cooling fan - then consider fitting one...soCaDakota will do you one but there are alternatives.

Chris

 

I have absolutely identical symptoms as you, except no power loss and it's on Ford 351 CID. On thing I did was do that you didn't yet is do a block test (from NAPA) to chemically check for combustion gas in the radiator. Instructions say the blue test fluid will turn yellow if the combustion gas is present. In my case it turned green and I'm certain there was no green antifreeze sucked into the tester. No mention of what green means except on a diesel engine. A shop then did the same block test and said there's no combustion gas leak, as test fluid remained blue for them. Lower portion of radiator is 60-degrees F cooler than top half at normal operating temp.

No coolant loss, no moisture out exhaust, no coolant in oil, no oil in coolant. Replaced temp sender, thermostat, hoses, fan clutch, 5K on OEM water pump. Coolant is very clean and new, radiator 4 years old no corrosion inside. A/C condensor front is clean, no flow blockage. Have not done a leakdown test, but I suspect if there is a combustion leak it may not show up unless at full temp, and I don't see how it's possible to get in there to do a leakdown test at full temp.. Have not flow tested radiator yet, tested cat, or removed trans pan.

Did you ever solve this? If so, I'd sure liek to know what it was.

 

Tripellex,

Welcome to the forums. I would try Hydras recommendation to make sure that is not the cause of your overheat issue. Also, as Chris pointed out, power wash your A/C condenser coil to make sure there is no air blockage. Lastly, it may be the radiator. I had mine replaced early at 85k due to a tranny failure. Mechanic told me the radiator is about to go anyways as it showed signs of swelling on the sides.

To answer your power loss question, Dodge has incorporated a failsafe programming on the computer to prevent your engine from working any hard than it should be to prevent total engine failure once your temperature reaches 210 degrees. Your engine performance will feel like it is missing 4 cylinders. Once the temperaure drops to its normal operating range, you should get your power back.

Another thing that just entered my head, I remember reading on this forum ages back if you have a possible head gasket leak, this can cause overheating too. So you may want to do a compression test as prettygentle recommended.

 

I didnt see that you replaced the cap... could be that your cooling system is not holding pressure.