What should I expect for coolant temps on my 01 D2?
It has a has a new radiator, thermostat, water pump, and most of the cooling hoses. Its filled with Prestone green coolant. No coolant loss. Head gaskets were done somewhere around 20-30k miles ago. Car runs wonderfully and has no fault codes.

Using a scan tool at idle it reads about 208-215, 215-217 for highway driving, and city driving warrants anything between the 208-215. This sounds a bit high to me.

 

How bout you convert those temps to F and get back to us. Ain't nobody got time for that.

 

edit for temps to fahrenheit

 

You need to be under 200 and there is no reason why it shouldn't with the system almost entirely replaced. Maybe you didn't get the low temp Tstat or whichever one that you got is opening at well over 200f. You should have the 180-deg model for any effectiveness.
If you haven't replaced the viscous fan, that should have been done with the water pump. It should be a brand-new, heavy duty model and is paramount in keeping the operating temp stabilized when cruising at a slow speed and especially while idling in traffic. When you get these other 2 replaced (again) there shouldn't be any more than +\- 5 deg at any time.

 

^^^ Chubbs really does have amazing temps in his Disco. Verified. He can get you where you want to be.

 

The 180F OEM grey thermostat is a must vs the 190F OEM unit!

Right now my 02 Kalahari is running 175-190F tops. In the summer my temps are 188-205F (with the AC on).

Change the thermostat and you should see much better temps.

 

That's very warm. I'd lean towards a fan issue if you are seeing those types of temps at an idle. Changing the stat from a 190 to a 180 will change the opening temp, but once it is open...it's open...regardless. Once the stat is completely open...it is basically out of the equation. It has done its job, warmed up the engine...and then opened for passage of fluid afterwards. Once this is acomplished, then this is where the rest of the cooling system comes into play, sufficient air movement, coolant flow, etc, etc.

So, since you've replaced the radiator and if you are seeing temps well above the operating temps, you either have a faulty thermostat (not opening all the way) or a cooling fan issue.

Good luck,

Brian.

 

The norm is to see your highest temps in city or stop & go traffic, not at cruising.

Many see almost 30 F cooler on the highway and under 200 in traffic. As other suggest a 180 thermostat may/should help.

I'd also recommend a complete flush & cleaning of your cooling system including the engine block by removing the block drain plugs.
......

 

I find it works differently. If his temps were exceeding past 210 and climbing I would say the t stat is out of the equation.

When I have had trucks that run in the 200-215 range(stable temps) and have added a genuine grey t stat I have seen the temps drop to 180-195(stable temps). I think that one, the low temp stat opens fully at 180 as where the 190 doesn't and two, by getting a jump on the full flow of coolant you can stop the temps from climbing. Now I'm not saying there are not other issues contributing to his high temps, but a genuine 180 will bring his stable operating temps down.

 

I did a lot of cooling comparisons between my two identical D2's. Both were in great conditon and one had the 180F OEM thermostat while the other had the 190F thermostat.

What I saw with the 190F thermostat was a smaller temp range vs the 180F. In TX and in traffic with the AC on the 190F unit would give me a max of 206F with a driving range from 195-206F. The 180F would give me a 188-204F range in the same conditions.

I also noticed much better cooling at say the 55-65MPH range. Once up into the 70-75MPH range the air flowing thru the radiator didn't seem to keep the temps in the 188-193F anymore and the temps would creep up to 200F then if you stayed at the same speed/RPM you'd see the temps go back down to 193F then eventually back up with the 180F thermostat and repeat the cycle.

My recent experiement was with the Ford Explorer/Ranger Dorman 620-112 18inch cooling fan with the Severe Duty 99-02 D2 Fan Clutch.

What I've noticed with that setup is that it pulls much more air at slower speeds. The fan is also slightly louder vs the OEM fan blade as the 620-112 doesn't have the ring around it. But for 25.00 vs $$$ for an OEM 99-02 unit I see it as a great replacement and it should help a D2 to cool slightly better while out on the trail.

Also your coolant temps will vary depending on the mixture of your coolant.