Your temps are correct for a stock thermostat.

Believing you have it bled isn't good enough, you have to KNOW. You've done step one of the bleed procedure. Step two is looking in the bleed screw hole first thing in the morning when the engine is stone cold... or any time in the day if you have not yet started it up. If there is room to add any more coolant through the bleed screw when everything is cold, then you have found an air pocket. Sometimes it takes three or four attempts at this before you no longer need to add.

Also what 180 degree stat did you order? The black and grey ones are the best. There have been reported issues about the white ones, some defective, some labeled incorrectly. The grey one is a Britpart, the Black one is a LR OEM available from Lucky 8...

Best of luck!

 

Thanks. I ended up ordering both thermostats you mentioned. The britpart PEL500110 one and the "GENUINE LOW TEMP THERMOSTAT" from Lucky8. I heard sometimes you can get a bum one so I figured I would get one of each.

For the bleed procedure you mentioned... when you crack the bleed screw to see if you need to add fluid, do you raise the tank at this point or do you leave it in its position?

Thanks!

 

most people do not raise the overflow tank and just fill at the bleed screw. however, being less than coordinated and not having a funnel with a small enough spout to fit properly in the bleed screw hole, i undo the bleed screw and if there is no coolant showing i raise the overflow tank until coolant is coming out of the bleed screw hole. then with the overflow tank still held higher than the bleed screw hole i thread the new brass bleeder screw, because i'm sure you've thrown out the crappy black plastic bleed screw, back into place and then lower the overflow tank, resecure it, put the cap on and have no issue with air bubbles.

i don't think that i have use the word hole so many times in one paragraph before.

 

As for getting coolant into the bleed hole, I've had success just pinching the side of a used paper hot beverage cup into a V shape and usually i've never needed more than an ounce or two. Raising the overflow tank works too, but just pouring it into the bleed hole is less work. I, like some folks have tried the parking uphill and opening the bleed hole in the morning method, that works too.

 

It seems like my temps remain high when moving:

216f while cruising at 65 and 220f when stopped again. I am not driving anymore until I get my 180 thermostat mid next week.

This suggests it is not a fan problem, right? If it was just the fan, it should cool down dramatically when moving quickly.

 

216 is alot higher than I get at 65--and I'd pull over at 220--but I have a 180 thermostat (inline, which was mentioned by someone else above). Your earlier comment that,

In regards to temp sensor / sender:

• Took some readings around the sensor / sender and they are about 15F cooler than scan gauge.

seems to point to a sending unit problem.

​​​​​I checked the engine tonight and the delta was only 3 degrees (192 near sensor and 195 on scangauge alternative) after driving an hour and half, checking when I stopped. Similarly, your delta from driving temp to stop temp is in a tight range.

Everything looks good except the numbers, so I'm suspecting your sending unit.

But another point you made confuses me. The temps below and above the thermostat were 113 and 190. You have a 190 thermostat so maybe it hadn't quite opened yet. A bad thermostat is a possibility, but only if it isn't opening fully because if it didn't open at all you would overheat super fast.

I also wonder whether your Disco has an oil cooler. Some do, some don't. Mine does and that could make my temps lower than yours in general. With a new Turner engine (which will surely outlast me, anyway) I would want an oil cooler.

Finally, do you have red or green coolant, and were the temps you provided with AC on or off?

Is your radiator new or verified good? You do have a mechanical fan, right? Not an electric setup for the main fan? No fancy grill guard with tight mesh?

 

This. I was chasing all sorts of problems with my truck when i finally figured out my NEW sensor was fubar. Replaced it and all is well now.

 

First of all, thank you!

If you don't mind, where specifically did you temp on the engine or cooling system? Some options I tired are: manifold, heater outlet tube, coolant outlet tube (j-pipe).

The radiator is brand new. The temps I provided is actually with the heat on, to keep temps as low as possible while debugging. At idle, the AC makes no difference in temps.

No fancy grill, stock looking fan (mechanical with clutch on back of radiator and smaller fan on front);

I do not think I have an oil cooler. I added a sandwich plate style on my WRX, I wonder if I could do the same here. I would love the peace of mind to keep everything cool. I am all in at this point so lets do it!

In regards to the 113 / 190 difference between bottom and top of thermostat. I see two potential explanations here:

Theory 1: The temp sensor is bad. The engine really is running around 195-200 when the scan gauge says 215. Because of this, the thermostat is barely open and thus, the lower hose from the radiator is cool and the upper hose remains relatively warm. Once the temp gets to 205 (reading 220) the thermostat is fully open and temps stabilize.

Theory 2: The thermostat is slow to open and the temp sensor is more or less correct. The thermostat is letting just enough cool water from the bottom through to prevent overheating, but it slow to open or only partially opening. This would explain why the upper hose into the water pump is always quite warm. This does not explain why the IR thermometer reads so low.

In any case, thanks for thinking this through with me.

Does anyone know how I can verify if the temp sensor is correct with a meat / candy thermometer?

I have a new temp sensor and 2 180 thermostats on order. I will boil them in water, put on the one that opens first, and then boil the old one when it comes off to see if that makes any difference. I suppose I should only change out the temp sensor first for science. We will see if I am that careful

 

Also, it is strange that I can get lower temps while not moving and revving to 2k than I do while moving.

 

Not really strange, but when reving in park you arent' really putting the engine under load

What seems strange to me is that your truck left the shop in this condition -- wouldnt they have made sure it was working properly before returning it to you?