Overheating Durango, I give up!

[occupant]

Parts replaced, in order, to alleviate overheating issues:

1) Radiator, fall 2009
2) Water Pump, spring 2010
3) Radiator again, spring 2010 (cracked when water pump failed)
4) Upper and Lower hoses and clamps, spring 2010
5) Heater hoses and clamps, spring 2010
6) Radiator cap and line to burp tank, summer 2010
7) Bypassed leaking heater core, spring 2011
8) Thermal fan clutch, summer 2011
9) Electric fan, summer 2011

System has been pressure tested and holds 19lbs just fine. Heater core function shouldn't be required to maintain cooling system integrity and performance. So where I'm at is the truck runs great with the AC off at any time. With the AC on, in 95+ degree heat, in traffic or at low speeds, the truck will go above 210 degrees. Electric fan is now working properly, it comes on just below 210 and stays on. Rear AC gets nice and cold but front AC gets hotter as the engine heats up. This should have been eliminated when the heater core was bypassed. Now I'm not so sure.

If I keep driving it'll settle just above 210 and stay there. Turn it off it goes halfway to 260 when you restart and it'll come back down to just above 210 and stay there. The AC won't blow cold again up front until it drops below 210 and that takes 6 to 10 miles of highway cruising above 50mph. As soon as you get off the highway it heats up again.

My theories:

A) The engine has a slightly blown intake or cylinder head gasket and combustion gases are heating up the cooling system.

B) The radiator that was installed is a cheap piece of garbage and is probably one row and not up to the task of a V8 truck with front/rear AC in 100 degree Texas weather.

C) The condenser is clogged up with dead bug guts and that's making it inefficient and it needs cleaned or replaced.

D) The cooling passages in the engine are clogged up somehow that the flush in spring 2011 didn't git 'r done.

Any other ideas? This is our primary vehicle and really I just need it to survive a few more months for my wife to trade it off on a new Explorer (or Durango or Acadia or Pathfinder or 4Runner or whatever she likes best when the time comes to blow $30K on a new truck).

 

[cos]

Have you owned the Durnago since it was new?

If so how often have you changed the coolant?

 

[Tim4mods]

I'm not familiar with that engine but some can get air in the cooling system and cause the temps to go up this usually happens right after a flush or if its allowed to run low. Could also be a thermostat problem I didn't see that mentioned as one of the replaced parts. Hope you figure it out and good luck!

 

[daves87rs]

I can't put my finger on it....but if you can a good deal on a truck now, I'd do it.

I'm think throwing parts at it now could be a waste...better spent of something newer since it is your main ride.

 

[Warstud]

Try a new t-stat and bleed the system. If that doesn't work...have a combustion leak test done. You may have a bad head gasket.

 

[Jim 5]

I would bet on a headgasket as well.

 

[Turk]

Yes to the above + put in Amsoil Coolant Boost!

"Dominator Coolant Boost is formulated with proprietary tiered surfactant technology, providing quick and effective heat transfer inside radiators and cylinder heads, which results in reduced operating temperatures, more efficient operation, increased horsepower..."

http://www.amsoil.com/storefront/rdcb.aspx

 

[OVERKILL]

Originally Posted By: tpitcher
Yes to the above + put in Amsoil Coolant Boost!

"Dominator Coolant Boost is formulated with proprietary tiered surfactant technology, providing quick and effective heat transfer inside radiators and cylinder heads, which results in reduced operating temperatures, more efficient operation, increased horsepower..."

http://www.amsoil.com/storefront/rdcb.aspx



That is NOT going to help. He has an issue that requires something that is broken.... to be fixed.

 

[occupant]

Not owned since new, in fact it had a blown motor when we bought it 2/09 at 172K, and we had a used engine (124K) with 155lb compression on all 8cyl installed at that time. Overheating has only been a major problem the last 6-9 months. Before the water pump failure, the replacement engine never went over 210. Since, it's just been getting progressively worse.

Thermostat was replaced twice, once with the water pump/hoses and once again with the heater core bypass. I didn't notice huge amounts of crud in the system. Didn't notice any, really. No bubbles, no foam, nothing but green coolant mix. No oily residue either, which is why I'm wondering if it's an intake gasket leak, not a cylinder head. I don't know.

I'm going to pull and pressure test the radiator cap and then the system again. There has to be a pressure loss somewhere or else something is plugged up. And I need some of that blue stuff to do the exhaust gas test. I have front brake pads and rotors to go on so I'll knock that out and then do this cooling system thing. All this prior work was done by a mechanic and a Chrysler dealer. $730 spent on the two fans alone!

 

[tinmanSC]

Originally Posted By: tpitcher
Yes to the above + put in Amsoil Coolant Boost!

"Dominator Coolant Boost is formulated with proprietary tiered surfactant technology, providing quick and effective heat transfer inside radiators and cylinder heads, which results in reduced operating temperatures, more efficient operation, increased horsepower..."

http://www.amsoil.com/storefront/rdcb.aspx

 

[rslifkin]

I'd make sure the fan clutch is good (even if it's been replaced, check it), make sure the rad and condenser are clean, rad is large enough, and check for a blown head gasket or cracked head.

 

[DrDusty86]

Also check it on a different temp gauge just for grins. Maybe its not overheating at all. My Buddy's 03 Chevrolet 5.3 was getting up to 240* on the factory cluster, but when hooked up to another gauge it was at 190*.. It scared the [censored] out of him. It may not be overheating at all. Does it "smell" hot? Is it dieseling? is it pinging?
Dusty

 

[occupant]

Good news is if the electric fan or the thermal fan clutch are not good, I have 12mo 12K warranties on those since they did get done at the dealer.

Wife just got back from a shopping/errand/grocery trip, she had to leave the air off for most of the short trips. She does NOT like driving with the AC off to keep it from running hot. I do NOT blame her. Was 106 earlier and 102 now. Ouch.

Sent off a couple inquiries about some used vehicles locally. It might be easier to just get her another truck and let me tinker with this while not having a time limit. It's hard to take things apart even for testing if wifey decides she needs to run to Wal-Mart in an hour!

I'm not adding snake oil to it, tpitcher. That conditioner will change what, exactly? 6 degrees cooler in a 50/50 mix? I'm looking at this truck running 20-30 degrees hotter than it should be running. It's a physical problem. That stuff you're hocking is not a mainstream product. It's for drag racers and road racers. I wouldn't put it in a grocery getter unless that grocery getter was a '70 Vista Cruiser with a four-barrel 455 under the hood, headers, 4-speed, posi, and I had a 6 minute time limit to get in and out of Wal-Mart and be home.

 

[JoeWGauss]

occupant,

why would you buy this thing when it clearly was dead and needed so much work?

I'm curious. There are so many better choices than that it would appear.

 

[DrDusty86]

Maybe he got a smoken deal on an otherwise clean Durango. I Saw a 06 TDI Jetta 5spd go for $600. The owner just wanted the Homeowners Asso. off his back It needed a motor due to a failed timing belt. THAT CAR WAS SHOWROOM otherwise. I didn't have the time for it.

 

[onion]

What year is this durango?

When you have an older vehicle, or a vehicle that has had this much work done to it, there's much potential for NEW problems to have been introduced along the way. And you've covered some of these:

Is the 'new' radiator the correct one? What about the 'new' thermostats? Are chunks of gasket from the old water pump clogging the thermostat? Did some rocket scientist leave a shop rag in the radiator hose? Or kink it?

So I agree with most of the suggestions posted this far. But without being able to see the vehicle in person, drive it, check temps with my infrared gun, and otherwise lay my healing hands upon it... it's hard to say what's going on.

If there's a blown head gasket, you'll usually see some of the following symptoms: coolant loss, excessive cooling system pressure & blowing coolant out the overflow, and visible signs of soot in the coolant an/or an odd smell to it. Of course if a head gasket is 'barely' blown, then these symptoms may be 'barely' noticeable.

You might have a look at the condenser fins. It seems to depend on grille design and driving conditions, but I occasionally see vehicles with LOTS of the condenser fins laid over from road gravel and the like. Can't be good for air flow.

 

[qdeezie]

I'd say check the parts you've already put on there. With my truck, I bought it as a fixer upper and certain brands of parts I put on my truck was junk brand new right out of the box. Tried a different brand and no problems to report. Have had this to happen a few times.

 

[JHZR2]

So let's get this straight... Did you replace the radiator the first time because there was a failed water pump... And then you replaced both again (the spring 2010 services)?

Otherwise, why did you replace the radiator the first time?

Is it an OE radiator? Chinese made?

A lousy part could do it, as could the air bubble, bad thermostat, etc.

Getting off the highway and shutting down will let the system heatsoak, and the needle will have risen at the next startup... Seen that before, nothing odd there, so long as it comes back down.

I think al your ideas are solid, and Id start looking at them one by one. Start with the condensor being clogged as #1, since it is the easiest, and go from there.

Good luck!

 

[Chris142]

Does it puke when it shows hot? Check the actual temperature with a mechanical guage or infrared gun. Maybe when the AC is turned on it changes the ground resistance and the guage moves but the engine temp stays the same.

It's not uncommon for an engine to run 220 or so on a hot day with the AC on.

 

[MrHorspwer]

Originally Posted By: Chris142
Does it puke when it shows hot? Check the actual temperature with a mechanical guage or infrared gun. Maybe when the AC is turned on it changes the ground resistance and the guage moves but the engine temp stays the same.

It's not uncommon for an engine to run 220 or so on a hot day with the AC on.


Agreed on all the above.

210 degree coolant temp on a 95 degree day is a perfectly normal operating temperature. Heck, most FWD cars don't turn the cooling fans on until near 220 degrees.

What are you basing the temperature on? Tell me you're not using the gauge in the cluster? Get a scan tool and actually monitor the coolant temp sensor as read by the ECM.

As for the temp spiking when your turn the car off... again, normal. When the engine is off, the water pump isn't circulating any coolant. The coolant in the engine, where the temnp sensor is, is just sucking up latent heat. As soon as you start it again, all the coolant that's been chilling in the radiator is swapped with the hot stuff in the engine, and bob's your uncle, temp is back to normal. Normal, normal, normal.

Why does your A/C get warmer when your stopped, even though you've diverted the heater core? A/C pressures rise and A/C cooling capicity decreases as airflow over the condensor is reduced. When you stop, it's relying only on the air being pulled/pushed by the electric and mechanical fan. This is a small amount compared to the air flowing past the condensor at even 30 MPH. As pressures rise, evaperator temperature and outlet temps will also rise. Normal.

If the engine temp is bothering you so much, my advice would be to put a piece of tape over the gauge so you can't see it anymore.