So, I replaced the thermostat with what is supposed to be a 180 deg model. I bleed the system and replaced with fresh green coolant, I even added some Lucas stay cool stuff. I am sure I overfilled it when I added the Lucas. Well, I am obsessed with checking the temp while The Demon is running and they seem to stay around 207 while idled and will go down to 201 at highway speeds. Does this sound OK or am i just crazy thinking it should be around 190? To top it all off, I found some green coolant in a tiny drip hanging on my bell housing close to the transmission pan. I am pretty sure that is some residual from the overfill that came out while obsessing over the idle temp this afternoon, or it may be left over from the "drain" yesterday. For some reason I am worrying about that stupid drip bubble.

 

Seems high for a 180 degree stat. Did you buy a genuine 180? Those temps seem more inline with a 190. iirc I think those idle around 203 or so.

Mine idles at 189 most of the year.

 

A bit high but youre fine. Like akrover's temp is normal with 180 tstat. About the drip, just check your levels if it dips a lot in a week or so. Just keep an eye on that drip

 

If your temps go *down* when you are driving (which is higher RPMs which is more heat overall than just idling) it might mean that your overall cooling capacity is good, but that your fan clutch or fan blades aren't so great.

The driving is circulating more air.

 

I had a situation almost identical to yours. I went through the usual suspects like coolant tank cap, etc. Finally got out a little mirror and looked at the rear of engine behind no. 7 and found a blown head gasket.

 

 

The PO of my car had a lower temp thermostat installed. It was a 180F aftermarket that gave me 195F while running and around 203-205F while idling.
Installed a genuine 180F version and can cruise at around 183F all day with 190F while idling in hot and humid weather.

 

I have a grey 180 and am at 200-206 cruising, before recent head gasket job. The head gasket was leaking, as well as the TB Heater, I am really interested to see if I get down to where you are at after the system is fully bled and pressurized.

 

Supposedly, the PO had done a head job on it but it seems like he wasn't that honest about everything to me. When I get home this evening I will take her to the car wash and spray the undercarriage to make sure i don't have any residual drip. I probably should have bit the bullet and bought the expensive 180 deg thermostat instead of the aftermarket one.

 

dittos on the temps, sound about right for the cheap aftermarket 180... The only worthy cheaper aftermarket 180 that people on here have been getting good results from are the Britpart unit. Both that and the Genuine grey LR one are what to use if you want down below 200 degrees... followed of course by meticulous bleeding. If seen a proper bleed yield a 10 degree improvement over a rudimentary bleed.