My Van runs fine and gets decent mpg but only heats up to around 145 degrees warmed up. I’ve changed the thermostat and checked the temp with an OBD tool and it matches the dash gauge. Just wondering if this is normal, at what temp do some other vans here run?

 

If the sending unit is reading wrong, the gauge and reader will read wrong. Get a remote infrared thermometer. This is a dandy little tool with lots of uses. If the housing at the thermostat is reading 145 on that, your engine is running cool. You don't say what year or engine you have but I'm betting it's a V-8 with at least 120,000+ miles. Has your fuel mileage dropped? I suspect a worn timing chain as it will still run okay, but never really warm up. This reduces heat in the winter and increases fuel consumption as the computer is stuck in "open loop" mode. If you're van is in the 90's or earlier, you may need a new timing chain. If it's worn, a replacement will raise your fuel economy and really run you out with heat in the winter.

 

Its a 2000 ram van 1500, 3.9L v6 with 117,000mi. The fuel is decent around 16-17 mpg which is average according to fuelly. Wouldn’t a timing chain throw a check engine light? Is there an inspection plate I can remove to look at the tensioner like my Toyota had?

 

No, but if you know what to listen for you can hear a "shika-shika-shika" sound from the timing cover. I had a '94 Ram with the 3.9 and it didn't throw a code. I replaced mine at 120K. The nice thing is your engine compartment was designed to take a V-8. With the fan and shroud removed, there's all sorts of room to work on the front of the engine.

 

Ol grouch is on to something...only reasons it would run that cold is a 160 degree thermo or a bad timing chain...they do go bad a lot on the 3.9...I had to do mine too...
Or the sender, which is next to the thermo housing could be bad too...

 

Yep, it was stuck open so I replaced the thermostat with one of higher quality. However it idles around 185 and I feel like it should get warmer, the heater is barely warm and not enough to Defog the windshield in a few months. I suspected the heater core was clogged so I ran a pump through it with some rust remover but broke the in line valve in the process, oops. I just put a 5/8 hose nipple in there for the time being so the core is always in use. Still can’t figure out why the engine won’t warm all the way up.

 

With 117,000 miles, the chain may be getting to where it needs replaced. If you put a 195 thermostat in, the engine should be that warm at least. If you aren't sure, take it to a trust worthy mechanic and see what he or she says. I prefer the first generation Magnums over the newer ones. That however is the one weak spot they have.

 

the ol grouch may be on to something. I love these Magnums too...but
do you really have an issue?
A bad timing chain would have to be terrible to throw a code, and at that time it would be noticeable.
The computer is compensating and within range, so technically you don't have an issue - technically.
When I refurbed my 3.9 @ 115k I did the timing chain as insurance. So I haveny seen this issue, but many times, timing is the issue when it doesn't warm up all the way after when you have checked the cooling system over.
If you cant get out the stethoscope and listen to the timing chain cover, I would find someone who can help. I am all about supporting my local indy mechanics
The 3.9 in our vans is good as long as it isn't in a conversion...I ended up wearing my 3.9 out at 150k (IMO) and that is when I swapped the 360/46RE into it
There are other possibilities too-maybe the radiator isn't OEM/to spec/too large and was a bad swap sometime before?
Did you replace the PCM temp sensor just for insurance? Just trying to make conversation