hi, i have a 1998 durango v8 5.9L 4x4, that i recently bought. i bought it in feb. and now in aug. its over heating. when we bought it we welded a thrush glass pack, short cold air intake, and new bigger tires. at first we thought the issue had something to do with one of these things. so we took out the cold air intake. we have had the radiator, heater, and engine flushed, belt drive, flushed trans; fan clutch, replaced thermostat cause it didnt have one, spark plugs, & fuzes checked and working. i am thinking it is the radiator because the a/c radiator(not sure if correct) is dented and the radiator is right behind that. i am not sure how to check if it is clogged or not. i was also wondering if i would be an electrical issue, since a week ago i seen the dash lights turn off and then right back on? we have a obd2 and it showed two codes p1388- asd relay control circuit open or shorted and p0545 exhaust gas temp sensor circuit low. so i cleared them and have been driving it still overheats but no code have showed up. in the live reading says
* fuel system 1- open loop
2 - n/a
load value - 5.8%
STFT- bank 1 - 0.0%
LTFT - bank 1 - 3.1 %
manifold pressure- 12.0 in.hg
engine RPM- 804 rpm
ignition advance - 84 F
throttle position - 13.6%
bank 1 - sensor 1-025 output 1.000v
bank 1 - sensor 1- STFT 0.0 %
bank 1 - sensor 2- 025 output 1.000v
bank 1 - sensor 2 -STFT 99.0%
Intake - 219 F

i have no clue if this is all normal or not. im thinking that 1/1 sensor is not right. also would anyone have a wire diagram?

 

is your clutch fan still good (no e-fan on your truck, so not electrically related), check by spinning the fan by hand with the engine off, if it spins more than 1/2 a turn, the clutch is bad, chances are if that is the problem you wouldnt have an issue on the freeway.

you can see if the radiator is blocked by taking the hoses off and running water through, if it comes out the bottom its 'clear'

however we have had a member (magic84 i believe) who had a similar problem, and it turned out to be the radiator partially clogged, therefor not cooling efficiently, i believe he had 'hotspots' on the radiator which were found when checked with an infrared laser thermometer ($20-$30 at harbour freight)

 

i turned fan and wont even turn. i turned the car on and stuck a cartboard and it did not stop the fan so i know it good. i also checked the radiator temp. for hot spots and was 10 degrees differance in some spots, further to the bottom. i dont know if that would be considered clogged or not? at high speeds i have not noticed overheating as fast as at low speeds it just goes up.

 

Would a o2 sensor be the cause of the engine over heating????

 

A leaner running engine will run quite a bit hotter.

 

yes mean you are correct, but i dont think it would be hotter by enough to cause it to overheat, so the final answer would be NO a bad O2 will NOT CAUSE OVERHEATING

 

It all depends on how lean the engine is running. I'm not saying it is his issue but it is a possibility.

 

1st, you couldn't turn the clutch fan? Well that's your first problem. The clutch is frozen and needs to be replaced.

2nd, with hot spots in the radiator the radiator needs to be replaced.

3rd, the person most likely removed the T-stat and purposely ceased the fan, to get it cold enough to sell to you (because it had a bad radiator) and make someone think there was no issue in the first place.


I would ensure the head gaskets are good by making sure there is no water in oil, oil in water, steam in exhaust, or compression or other tests.

 

the fan clutch was the first thing we got replaced, b/c it wiggled and kept on spinning, but do you think it would be it again? how would you recommend me checking the radiator? how does the coolant run? is it normal for the radiator to be cooler at the bottom or should it all be at the same temp? am i looking for a real dramatic change in temp?

 

If the clutch doesn't turn and is locked up tighter that a wealthy woman's legs then it could be kind of engaged already. Take it for a mile ride to ensure the fan is not engaged and turn it off and ensure that fan is not engaged and that it can turn concerting you already replaced it.

As for checking for hot spots:

You stated that you had 10 degree hot spots already so I would think you have checked for the hot spots using a radiant thermometer. You can take temps all over the place looking for hot and cold spots. Cold spots would be a "bad" or "plugged" spot and water is not circulating through that section so it is rendered useless. If you have these spots then the radiator is no good because only portions of the radiator is being used.

Also, your issue could be caused by a bad water pump.


Now remember that there is a small place about 3/4 the way down that has 2 rows that is for the transmission cooler and not the radiator so it could be cool there. Other than that it should be the same temp.