You shouldn't need to block the radiator. In -10ºf my truck heats up just fine, usually within just a couple of miles.

When they flush the heater core make sure to disconnect both hoses and flush it out, backwards too.

 

I've never had a problem with the bolts, but then again I have small fingers that easily fit that awkward spot.

 

Mine takes about 6 miles to hit 180 right now. I've started running it in 2nd or 3rd (OD off) to build heat quicker. But that's with the lincoln fan coming on with the key..i can probably unhook the jumper and go back to thermostat controlled if I wanted.

 

It's at a local shop. Not sure how they're gonna do it. I don't have a long enough hose here or I'd do it myself.

 

I don't see how anyone (even with small hands) could put that front bolt in behind that AC compressor bracket. Nearly drove me insane the other day when I did it. Took about an hour of struggling to finally get it in the hole.

 

I'd put another t-stat in it. If the coolant is circulating and it's still not warming up, the t-stat is not working. If yours is stuck open, it will never warm up. A t-stat that is functioning correctly should let the truck warm up. And if it's not at the right temp, it will close off coolant flow until it is warmed up.

My '97 3.9 seems to run cold too, but I do have heat and with the fan on low, it feels pretty warm. If I have to turn on the compressor to defrost the windshield, I freeze. My guess is that Dodge sized everything to accommodate the V-8's and larger cabs, and it overwhelms the heater core.

I may have to try blocking off part of the radiator though.

Let us know what you find out and good luck with it.

 

If it not for that (1) bolt on the housing being nearly IMPOSSIBLE to get back into place, I would do the job again in a heartbeat! It seriously is that big of frustrating, time consuming PITA, that I will NEVER do that job again. Unless, you have very tiny hands (my hands are no big BTW) save yourself some grief!

I actually went and bought another thermostat yesterday and "started" to redo this job once again. This time I removed the alternator first. Well, even doing that it still did NOT improve the access to these (2) bolts. I said to myself....."F**K it! I'm NOT doing this again!" and put it all back together.

There's a YT video of dude showing just how EASY it is replace the T-stat on a 3.9 Dakota. His video is "only" about 1/2 long. Very nice and detailed....BUT! There is a spot in his video where there is a BREAK. Guess what spot in the job he's at at this point ? Yea, putting those (2) PITA bolts back into place. The video comes back and he said he "FINALLY" go those (2) bolts back in and goes on and finishes the job. He NEVER showed or explained exactly HOW he was able to get those to ***** back in place. He simply (like a LOT of YouTubers do) glossy over the PITA, frustrating parts of working on cars (or anything else).

Can you hear my frustration just telling ya'll about this job ? LOL!

BTW, "if" this flush/fill (being done to my truck right now at the shop....) below is MY fix!

No, SERIOUSLY ! LMAO!

 

I should know something real soon if the shop was able to get my issue resolved or not.

I'm not optimistic at this point.

 

Ok, got the truck back this afternoon and it is running a bit hotter. Perhaps 10-15 degrees or so based on the gauge's guess. The heater output appears to be a bit better as well.

The shop said there was a bunch of crud that flushed out so that is a very good thing. Obviously.

I still feel the new thermostat I put in the other day is stuck open. Just like the original one was .

At this point, I'm gonna just block off the radiator with some cardboard when the outside temp drops below 40 degrees.

I really would like to replace the thermostat once again (I bought another new one and TESTED it... works good), but do NOT feel like going to battle with those (2) damn bolts! LOL!

Anyone have good tips on getting those housing bolts back in ?

Thanks again for ya'lls input!

 

i may have used needle nose pliers or a magnet. But i could have sworn i put them by hand.

actually, i bet i put them in the housing, and dropped it all as an assembly.