Ok so I have a 99 5.2 V8 SLT 4X4 Durango with 240,000 miles. What could cause it to smoke sometimes if you leave it idling for a while, its not a dark smoke but it does have some color to it but its light. It also has a strong odor to it almost all of the time. What causes this?

Another question, I just had the cooling system serviced. They replaced the bolts and gasket on the thermostat housing, and flushed the radiator. It doesnt really leak any more but I have had to top off the overflow bottle with water every other week or so, but not much. BUT if i leave it idling for a long period of time (like sitting in traffic) then it starts to run hot (over the half way mark). Why?

 

Did they burp the system, if not i would start by doing that. Also, i would change the thermostat if it was not done.. sounds like it was not...

 

Yah theres no air bubbles in the radiator, and it stays full. Whats next?

 

Anyone know why it would smoke, smell or overheat?

 

Well you could have a few problems why it smokes. 1) Valve seals are leaking, 2) The lower plenum pan has gasket leak, 3) or the piston oil rings are causing a lot of blow by.

Cooling system overheating, Pressure check the cooling system and find out where coolant leak is. Do you have an aux cooling system pump on the passenger side under the hood, could be water pump, and also check all the freeze plugs for leakage.

 

MM:

At 240K, you could have several things going on here. Has your D been maintained to a decent degree during its life?

The overheating could be a bad fan clutch or a partially clogged radiator.

As far as the smoking goes, could be valve seals or piston rings worn. Could also be the plenum gasket under the intake leaking.

As far as the coolant level dropping, when was the last time you put new hoses on it? Again, at 200K plus these items and more are all overdue for an upgrade.

Don

 

Someone correct me if I'm wrong, but the 5.2L is basically the same block (externally) as the 5.9L. With that said, this is something I found on my 5.9L...

I was losing coolant, but couldn't determine where/how/why. I finally noticed that there is an area around the thermostat housing where the coolant can puddle. If it is a small leak, it will evaporate off faster that is can overflow and drip to the ground. Check there to see if you that is where you missing coolant is going.

Has your D lost power? I would check your oil to see if it is milky. You could have a blown head gasket or cracked head allowing the coolant to mix with the oil...

 

Here is what the member wrote inthe first post.

They replaced the bolts and gasket on the thermostat housing, and flushed the radiator. It doesnt really leak any more but I have had to top off the overflow bottle with water every other week or so, but not much.

Sure they could still have a leak at the t-stat housing, The only way the member is going to find any leaks is to pressure check the cooling system. And it could be the fan clutch too causing the overheating.

 

+1 pressure test the cooling system and change out the radiator cap.

I would do a compression test.

Lastly, you do not burp a 1998-1999 Durango because they have a different set up. You start on a cool motor, first remove the radiator cap, place the heater on HOT and HI fan, start the truck pour your pre-mixed (green) coolant until full, increase the RPM to about 2000 rpm and top off the radiator while holding rpm, place cap on and lock down, then release the throttle. Fill the reservoir to the full mark.

Blue smoke is oil
Black smoke is unburned fuel
White smoke is coolant

 

n8ech, the durango has be maintained to a decent degree but not as well as it should..radiator flushed twice in its life, The most its ever gone without an oil change is problably 10k miles but normally about ever 5k miles, i just changed the oil it the other day and it was not milky at all. Original radiator hoses as far as i know. If i squeeze the hose going to the thermostat i hear a "ch ch" by the thermostat housing like it has a hole somewere, ive added a few ounces of water to it in the last few months so its not bad at all.

Samnbensdad, it has rust on the block around the thermostat housing from a previouse leak there (the mechanic said he almost had to replace the intake because the bolt threads were so buggered up. No coolant mixing with the oil. Not loosing power, it still runs strong.

Master Tech, the mechanic pressure tested the radiator and i watched the guage and it wasnt loosing pressure. It could be the fan clutch going bad, how could i tell?

Hydrashocker, it does need a new radiator cap, the bottom seal is chewed up. If i had to pick what color i thought the smoke was i would say blue so its problably burning a little bit of oil. It also leaks oil too, and transmission fluid, and power steering fluid, the differential leaks oil out of the fill cap, and a cv joint boot leaking etc etc etc

Edit: Old school i would like to replace the thermostat but the problem with that is if the thermostat bolts are removed again they may never go back/never seal properly and will leak terribly....again. Then i will need a new intake but the plus side is then i will have a new plenum gasket which ive heard could possibly by my smoking problem.