I have an 05 Dakota and I just wanted an opinion on temperatures. I replaced the radiator and thermostat not long ago and replaced all of the coolant. It hovers around the mid-line, never going too much higher or lower under any condition, but driving after warming it ranges from 212 (slightly under the line) to 217(mid-line beginning to peek from below the needle). Idling I get up to 219 where the mid-line is mostly visible below the needle, but that's the highest it will go no matter how long I idle. It tends to stay at 215 while moving, dead on the line, and just kinda moves depending on rpm (I've got the manual transmission with a clutched fan. Never goes above 217 while moving). I'm aware these aren't harmful temps, as it's just dancing around the line, but I've been suggested to use a 70/30 mixture on coolant, rather than 50/50 to get lower temps. I live in Florida, so that's entirely an option. The new thermostat is also one of the locking ones, so it's a little bulkier than the stock. Opinions?

 

Which engine?

With my V6 and stock cooling system/thermostat, also in Florida, the needle NEVER gets up to exactly over the halfway mark or higher (except immediately after a heat-soak from a hot shutdown and re-start a few minutes later). The highest the needle will ever go while running is a half-needle width below dead-center (the needle is overlapping the bottom of the halfway mark), period.

Immediately following a re-start after a heat-soak on a hot summer day as described above, the needle will start about a needle-width clear above the halfway mark, and then almost immediately fall to the position below dead-center as described in the previous paragraph.

If you have the V6, it sounds like your cooling may not be at optimal performance. Don't know if the V8 runs hotter though.

 

I have the v8. I'm going to go back to a stock thermostat and do the extra water and see if that helps at all. Aside from that, I don't have any gasket leaks. If it doesn't do the trick I'll just move on to the fan clutch I suppose. Either way it's nothing serious, but I'd rather keep my temps done before it possible gets serious.

 

I replaced my radiator and did a full coolant flush last year (still stock thermostat) and my needle stays just below the halfway mark (I can see the entire mark). What thermostat did you put in? RockAuto has stats but they are all 195 degrees. I wouldn't put any other thermostat in my truck other than Mopar brand, but that is just me. When you did the flush did you use one of those funnel systems on the radiator cap to ensure all the air was out of the system (heat from your HVAC also needs to be running at full blast)?

 

No I didn't. I just did an old fashioned burping. Mind posting a link to one of the funnels you're talking about so I can grab one?

 

My '05 Dakota 4.7 runs pretty steady hovering at 195-200 F according to the BlueDriver live data scanner. The thermostat is a Stant 195. The fan is oem thermostatic which automatically revs up and down based on the temperature of the air coming through the radiator.

 

10-4. So I'm running a hair hot, but nothing too awful. I'm suspecting it's either my fan clutch or thermostat. I looked a little deeper into the fail-safes like I've got right now and folks report them being hit or miss. I'm just gonna go back to Mopar and see what happens. Thanks everyone for your input.

 

I will add that I fully serviced my truck cooling system 2 years ago, 2017. Simply because I bought it used and had no idea when it was last done. The work entailed a complete coolant system flush with tap water and recharge with new coolant, a brand new thermostat, radiator fin cleaning with water and compressed air. I have done nothing with the fan clutch. It is working perfectly fine at 15 years old and 130,000 miles.

Changing coolant will do little to nothing to control temperature. What controls temperature are the three components mentioned. Thermostat, fan clutch, radiator. Ensure those are working properly, along with the water pump of course, and the temperature should be pretty rock solid at 197 degF, give or take a couple degrees and regardless of ambient temperature or load. If it is running cold or running hot, outside that 197 range, then one of those three components needs attention.

 

My radiator and thermostat are brand new. My truck has over 200,000 miles on it right now, so I wouldn't be surprised in the least of it were my fan clutch.

 

K - awesome. A couple ideas for consideration:
- I would probably buy and try another thermostat to be absolutely positive what's in there.
- Before installing a new one, or troubleshooting and existing one, I do test the thermostat submersed in a pot of water on the stove with a thermometer in. I do this to verify it is opening at the correct temperature and is working properly.