210 degree stat stock? That's a little high. Most durangos I know of comes with 195 degree stats. My 5.9 already starts to shutdown at 210 degrees. Runs like crap but designed that way so you won't blow a overheated motor.

One thing I did that really assisted the A/C cool down my cabin is to buy a light color dash cover! That's where most of the heat is being generated from in the cabin. After buying a light grey premium dashmat from dashmat, it takes very little A/C to keep a cool temperature in the cabin. And I live in the hot humid climate in Dallas / Fort Worth!!!

If you want your engine to breathe, other than adding a Cold Air Intake, you have to do the exhaust as well. Check out GS Motorsports true dual exhaust kit for 1st Generation Durangos/Dakotas.

http://www.gsmotorsports.com/Merchan...Code=GSMDUREXH

If you like to maintain the OEM look under the hood, check out Mopar's Cold Air Intake kit.

http://www.mopar.com/m_perf_subcat2C...=1145316815341

If you want even more smooth breathing, check out the M1 intake manifold

http://www.mopar.com/m_perf_subcat2C...=1145316894565

And check out Fastman's bigger throttle bodies

http://www.thefastman.com/Throttlebodies5x.asp

I also prefer reprogramming the ecm over using a piggy back chip. It was a proven by alot of dodge designers that the ECM will compensate the piggy back chip and all settings will return to normal thus, defeating the piggy back chip. A good programmer for the R/T's is the hypertech programmer III at

http://www.hypertech.com/programmer.html

 

Stock is 195 degree. You should always run a 5.9L at 180 degree to resist head cracking that the 5.9 has. Run a 180. They only run 195 degree's OEM for emissions.

 

Hi,

are you suggesting that the 5.9l engine (which mine is) is susceptible to head cracking...??
How would I know if this had happened...the reason why I ask is that my Durango is still running hot - with the temperature needle hovering at about 3/4's in trafiic, but drops down to just above vertical when at speed.

The manual seems to suggest that this sort of performance is normal since there is a tolerance for egine temperature operation - but I get worried when it starts to rise that high.

I got the dealer to replace the thermostat (don't know what temerature it operates at) but didn't help much.

The reason why I've got all neurotic about it was that I ran the vehicle for about 2 weeks with a leaking water pump - and yes I should have checked the coolant level. The giveaway was a hissing sound after I switched the engine off and a slight smell of fried oil. I should have taken it in immediately - but I went into to denial about it as an issue. Now I guess it was water turning into steam due to reduced pressure in the system combined with low coolant level.

Didn't do any really long journeys with it, just round town - but now I've convinced myself that its a blown head gasket or cracked head causing the over heating...

The engine itself seems to run fine with no misfires or other sounds at idle. Starts first time and I've checked the oil and there's no evidence of water. The exhaust doesn't seem a problem with no steam or water coming from it. A basic compression test by the dealer gives a range of results with the lowest being 120psi and the highest 150psi.

Anyway, any words of ressurance are appreciated - but is the 5.9l susceptible to cracking...??

Chris

 

I had to have head gaskets replaced when my engine got a little hot, about the same temps where you are currently running! Good thing it was still under warranty. Dealer says, your temp gauge should never go above 210 if you have the heavy duty cooling package which is standard on the R/T models. The R/T's have a safety feature when the temp hits 210, the engine runs as if it only has 4-6 cylinders. Not perform well but they programmed the PCM that way to save the engine from further damage.

My D has the factory 195 stat and will have it changed to 180 on my next antifreeze flush. My D rarely hits 210. Only time this happens is if it sits and idle after a long trip or if I make alot of slow stop and go traffice in the middle of a heatwave in summer. Rest of the time, it stays approx at 195. Only takes about 5-10 minutes for the temp to drop back down to 195 as I have an aux fan to boost air flow.

As you had water pump problems, you may want to have your radiator checked if you are hovering way above 210. It may be partially clogged up and not provide enough cooling.

 

At 120 PSI being your lowest, I doubt that you blew a gasket. I think your motor is fine. One way of seeing if you collapse a piston ring is to put two cap fulls of oil down the lowest PSI cylinder and put your compression tester on it and see if it comes up (which would show a leaking ring due to scaring or collapse), or nothing which shows no problem. Now if you loose pressure that should show a leaking head gasket.

Pull the thermostat if you ever have it go upwards of 220 degrees because it relaxes the spring on it. You should always run a 180 degree thermostat on that truck.
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Fix that water pump also!