I'm replacing my third thermostat and both radiator hoses while continuing to troubleshoot my constant issues of the truck running hot. I'm curious if the sensor adjacent to the thermostat housing and the one directly in front of the plenum are, in fact, in the wrong locations and should be swapped. I did not bother to take note of their original locations when I performed my engine rebuild, and bother are the same thread size/pitch.

 

VW,

Have you ever gotten a physical temp on that overheating? Is it possible the temp sender or gauge is just off? The two wire sends to the PCM, one wire is just the gauge. Do you have a scanner that can read off the PCM data?

 

Once mechanic I took the truck to connected a scanner which showed the timing too far advanced. We're talking over 19*. I know it's not a faulty temp sender/reading because the truck always blows coolant out of the overflow. Granted, that could be due to a leaking head gasket; however, I've checked the exhaust, smelled the coolant after having run the truck, burped the truck until I'm blue in the face, and I've even crumbled "dog turds" (leak stopper) that's guaranteed to seal any leaking head gasket -- and no change. My thought was that if those sensors are in the wrong location then the PCM would be advancing the timing, hence causing the truck to run hot.

 

OK, never mind. A quick check on Google brought me to a thread on the forum that answered my question and looks like I have them set up properly.

https://dodgeforum.com/forum/2486267-post6.html

 

im wondering if your crankshaft position sensor is going bad 19 deg thats alot wow..

 

right about here is where I tweak people.. Most folks don't wanna consider this particular sensor because of all the wiz-bang BS "500 more Horsepower and 145MPG!!!" claims on floggin' eBay.. but:

Replace your IAT just for grins if nothing else.

I went through a tangent some time back studying up on that thing and what it does.. I've not nailed down precisely when where and how it does the things it does, but it DOES do this- it adjusts timing, and has a lot of bearing on a/f ratio..

If the air is cooler (denser) it is more controllable, so it advances spark. If it is cooler and denser it is a little tougher to ignite- so it adds more catalyst (fuel).. it can do the opposite too.

The effed up thing about them, is they go bad without giving any codes or errors more often that they kick up a code.. Meaning, you could simply have a bad one- and that thing is sending data to your PCM telling it to lean out (which would cause you to run hot) AND advance the timing (which is the opposite of what it would be doing if you truly had cooler air in there, if it's telling the PCM to lean out, it should be telling it to retard at the same time- not advance).. But- we're talking about a jacked up sensor so there is no telling what data it could be sending.

I talked to one dude who said (paraphrased) "the only time I've seen a code for them things is when they're NOT connected or the wire was compromised somewhere".. he continued that "those things are pretty delicate and easy to break, and don't last a really long time"..

Man, they're like $15 at Advanced or Auto Zone.. Just give it a shot and see..

All of this I say, and I believe it, I also gotta say this- it's said that the o2 sensor has final say on a/f.. and at some point the PCM realizes the data from the IAT is bad and starts to ignore it.. but then it would set a code.. but it doesn't.. so they play tug of war and constantly alter your a/f and timing.. Lean runs hot.. I'm just sayin' give it a try.

 

Drew,

Thanks for your input. You're correct that people don't consider the sensors and the minute voltages they require. Just a ****-hair out of range will make the vehicle run like hell. +5V means +5 volts and even half a volt up or down can cause problems.

Any particular brand IAT recommended? I have to go to O'Reilly Auto Parts anyway to pick up a new thermostat housing gasket, so I may as well pick up a new IAT.

 

good info drew, thanks for taking the time.

 

thanks for the input drew..i will check that on my ram.. i have never changed that sensor..im deffinetly gonna put a new one in..

 

Vdub- I've no clue about the brand man, I just went with a dealer part because a guy I work with has a girlfriend who runs the parts counter (read: cheap) :-) I did price them at Advanced Auto though, and they were $12, or maybe $15.. It wasn't bad though whatever it was..

I don't know that I'm blaming that sensor for causing your grief with overheating- I DO know that you have had quite a time with it over the last year or so at least. I figured I'd toss it at you anyway..

I'd love to find some concrete information about that thing. It seems one of the most mysterious sensors on our trucks. One thing is certain, the information it provides has a lot to do with a/f and timing.