Lifted E30 V2

[Boris3]

Sounds like there is some circulation taking place.

Does the bottom radiator hose heat up at all?

Thermostat housing is all clean, no partial blocking?

I'd go back to KaiserRolls point about shooting with an infrared to get a sense of actual temps at the block, temp sensor housing, etc. You replaced the sensor and checked the plug wiring but how about the gauge (ground nut loose)? Still may be overheating but is the gauge reading the extent accurately?

You mentioned water pump blades and freezing earlier, when you stethoscope around the pump area any strange noises?

[jc43089]

I would remove and inspect the water pump, if the radiator flows and it will also overheat with no tstat installed, then there is not enough flow going around.

[GunMetalGrey]

Water pump was removed and inspected, and appeared to be fully intact. 

Only time I got lower rad hose temp was with the thermostat removed. 

All housings appeared to be free of blockages. 

Water pump to thermostat hose gets crazy hot, upper rad hose gets pretty darn warm, lower hose doesn't do much of anything. 

I added an additional hole to the upper portion of the thermostat and that didn't appear to help. Thermostat was bench tested / replaced to no avail. 

My only real lead lately is how hard the hoses got when at operating temp. They were darn near solid, but after the car sat overnight they went back to normal. 
I can tell it is overheating quite a bit because when it gets up in the temp gauge range it blows insanely hot heat from the vents.

[KaiserRolls]

Get a temp gun dude

[patsbimmer1]

The upper radiator hose getting hard isn't really relevant.  The cooling system is a pressurized system so the upper hose should get hard.  The only symptom you have is the lower hose doesn't get hot but with the thermostat removed it does get hot.  So your thermostat isn't opening.  That's the problem you need to be solving.

[GunMetalGrey]

patsbimmer1 said:

The upper radiator hose getting hard isn't really relevant.  The cooling system is a pressurized system so the upper hose should get hard.  The only symptom you have is the lower hose doesn't get hot but with the thermostat removed it does get hot.  So your thermostat isn't opening.  That's the problem you need to be solving.

All hoses are rock hard. Not just the upper. 

I'm aware the thermostat isn't opening, but I have come across no reason for it not to be. This is my problem.

[KaiserRolls]

Take the t stat out and toss it in some boiling water and see if it will open

[Boris3]

Did you try boiling the thermostats (stove test) to see if they open? Not unheard of to get new ones that are bad out of the box.

[patsbimmer1]

I'm just trying to say, don't over think it.  It's probably something very obvious causing it.

[GunMetalGrey]

I've boiled all thermostats and they opened just fine. Newest one I added an additional hole to assist bleeding. 

Trying not to overthink it, but I've done all of the simple stuff 3 times now and I'm getting nowhere. I'm running out of ideas. 

My only other thought is to try switching the heater core hoses, but since the heater works very well I don't think that is it. Though it's probably the last thing I haven't tried.

[GunMetalGrey]

Reference for later

[Boris3]

To rule out another simple thing, temp gun just to make sure the gauge reading of overheating is in fact correct. Gun is cheap, under $20 at HF.

You're still using the stock temp gauge? That was my issue when I was chasing an overheating problem on the m42. Pulled the cluster and tightened the nut on the back of the gauge. No more "overheating". If you tap the temp gauge when it reads high does it jump/move? Another symptom of the loose nut.

[KaiserRolls]

Get a temp gun dude

[Jdesign]

I would get a temp gun or an aftermarket temp gauge and see what your readings are.

I am also going to back up Boris mentioning checking the OEM gauge.

Also, not to say you are an idiot, as I have done the same thing before, but are you sure the T-stat is facing the right direction?

[straight6pwr]

guys, he tried without the t-stat and had the same problem. its not the t-stat.

[GunMetalGrey]

straight6pwr said:

guys, he tried without the t-stat and had the same problem. its not the t-stat.

I've kept my cool (pun intended) but mentally am getting annoyed at that question. 
Thank you for being the one to point it out lol. 

Car is back in from its time out, and will be looked at tonight.

Yes, I do have the thermostat in the correct orientation.

[KaiserRolls]

Hey Ben.

Do you have a temp gun

?

[straight6pwr]

GunMetalGrey said:

I've kept my cool (pun intended) but mentally am getting annoyed at that question. 
Thank you for being the one to point it out lol.

i think you need a post along the lines of

[HipMF]

and then when it turns out it's actually in backwards...

[Jdesign]

GunMetalGrey said:

Car is back in from its time out, and will be looked at tonight.

So did you look at it? I am sorry for bringing out the T-stat again. I am back to voting for a blocked coolant passage somewheres.