Just a pretty general question, not too much of a problem with the truck as it is curiosity. Well I just got done doing the water pump on my truck and rearend on my truck, its been layed up now for just about the past month and a half not driving since I've been at school, and only get a chance to work on it every once in a while if I go home for the weekend. All is said and done and I'm driving it again, and it just doesn't seem like it is getting as warm as it should. Although I throw on the heat, and the heat is still pretty hot I think so atleast.
-Just to add for info that the truck is a 1998 ram 1500 with the 5.2l.

The truck does have a 180 t-stat in it, brand new O2 sensor (I don't remember which one exactly but I do know I replaced the only one that really mattered more so after I re-did my plenum) and brand new antifreeze throughout and is tuned by hemifever. I do remember the thermostat reading slighting lower than the stock t-stat, but I don't think it was as low as it is now. I showed a buddy and his opinion is that the truck isn't getting warm enough to go into a thing called "open loop" I'm a little confused on that whole situation but have a jist of it. The truck runs fine, good power, starts right up, but does seem as if it does run a little rich but that could also be a result of the truck not reaching "open loop" I was told, which makes me to believe that it is not getting warm enough.

Now if that is true, I was told that these engines like to run cool anyway so don't worry about it, but was also told that these engines like to run warmer than normal? Now the tune that I have on it also, does require the 180 t-stat, so I am pretty confused on this whole subject. I just want to ensure that my engine is running at its optimal ability. Any opinions and/or thoughts on this subject are very much appreciated. I will attempt to upload a picture of what the thermostat looks like when fully warmed up. Thanks

 

Open loop: PCM runs engine from tables stored onboard. Ignores O2 sensor.

Closed loop: PCM uses O2 sensor to adjust fuel mixture to maintain 14.7:1 ratio.

Closed loop is where the engine is most efficient. It only needs to get up to 108 degrees to enable closed loop, so, your stat really isn't the problem. The PCM will 'see' the engine not getting up to its expected temp, so, it will run the engine SLIGHTLY richer. (which cools combustion chambers, and makes the engine less prone to spark knock.)

Our trucks also have heated O2 sensors, so, they start becoming accurate in less than two minutes after engine start.

What kind of gas mileage are you getting? Blowing any black smoke? How do the plugs look?

 

Oh okay, that clears things up pretty well. That is kind of what I had figured about the differences in loops, just to bring the engine up to the optimal operating temperature faster in a way. I get pretty good gas mileage I think so at least, I'm running 245/75/16 highway tires at the moment and I want to say I'm getting at least 12-13 around town, depending on how heavy my foot is as well, no black smoke either. I'll have to take a look at my plugs, but not right now since I'm away at school, but I remember before I did the plenum #8 was pretty fouled and #6 I believe wasn't looking too great either.

 

You mileage is right in line with what your truck should be getting.

8 and 6 being nasty are standard results of a blown plenum. Basically, you just wanna look at the color of the plugs, should be kinda light tan colored. If they are black, you are indeed running rich, ash deposits is burnt oil, white means you are running lean.

If your truck runs good, and doesn't exhibit undesireable behavior, I wouldn't worry about it too much.

 

Okay thats expected, not the best, but its a truck, can't expect much there.
I remember checking them both when I was making sure my plenum was blown before I went in and did all that work, and it was worth it, had 3 blowouts in the gasket. I'll hopefully get a chance to look at the plugs this weekend, they should be not too bad also, they only have about 2000 miles on them at the most. Everything is new on this truck lol.

I figured that it wouldn't be a problem, but I was given some other advice and just wanted to make sure. All is well then, thank you.

 

Did you put new O2's in also? OEM or NTK are best. And dump a lot of Techron+ in the fuel to clean the carbon off the valves for a few weeks. After a few weeks, use the techron+ every month or so.