A head gasket leak with brand new heads? I'd hope not, but hey, maybe. I'll have to check that out.

And I replaced the expansion tank cap. I pretty much replaced everything.

 

I have no idea unless you some how have air in the system. Brand new everything and running hot would **** me off! May want to try replacing the thermostat with a 180 if it's not already. Might be faulty and hanging up until it gets real hot. Cheap enough to try

 

I am more than p****d off! lol

I changed the tstat twice and truck has been doing the same thing. Who knows, my luck I got two defective tstats...

Though, maybe it is an electrical issue? Because my truck never actually over heats. The temp gauge can go all the way to H and my ultra gauge will read between 194 and 210. Plus when I shut the truck down when the needle is in H, and I restart it, the needle sits a little below center. Shouldn't it go back where it was when I shut the truck if that was the actual temperature?

This whole situation has got me confused. I am afraid to drive the truck lol I have no idea what the issue is and I don't wanna do anything to harm a new, re-manufactured engine.

 

Well the needle on the dash is notoriously inaccurate. There are two temp sensors, one feeds the ECU and that is what is shown on the Ultragauge. The other sends signal to the needle on the dash. Completely separate.

Bad sensor? or two?

 

I'd trust the ultra gauge. Mine rarely sees 195 when it's in the 90s outside and I just discovered the water pump is shot. Are you running a 180* Stat? If it's a 190-195 your temps on the ultra gauge are about right. For a bucks you can get a 160* Stat for a 67 Chevy c10 with a 327 and drill an 1/8" bleed hole in it to see if it drops your temps. I've been running old SBC 180s since I've owned the truck.

 

I changed both sensors. That was actually the first thing I did.

I drove the truck with ultra gauge hooked up yesterday. Ultra gauge went up to 194 and stayed there for a while, then I turned into a parking lot and my needle started creeping up to H. As this happened my ultra gauge went up to 215 and it stopped there. As I went to park and shut the truck, the needle came back down to the center as well as the ultra gauge back to 194.

However the engine isn't actually over heating. No bubbling coolant and my auxiliary fans do not stay on after shut down like they would if I were actually running hot.

I then drove 15 minutes and both gauges remained accurate. Needle at center and ultra at 194-195.

This is in 80 degree weather by the way.

The same day I let the truck sit and cool back down to 80 degrees. On my way home the temp gauge was erratic and so was the ultra gauge. It would go up and down in seconds. The ultra gauge went up to 217 once and then back down to 195 in less than a second. This doesn't seem possible.

I tried playing with electrical stuff, such as turning the heater blowers on, and it did nothing to affect the issue. The gauges just go up and down as they so please, but the engine is never actually hot.

Could this still be steam/air in the system, making the needle go nuts as well as the ultra gauge? Steam is pretty hot, and when an air bubble that hot goes by the sensor I assume its gonna make the ultra gauge get wonky readings.

 

I'm running oem stat from land rover dealer. I replaced my fail safe thinking that was the issue, but I still have same problems with both stats.

 

Just to confirm it's not overheating, how about leaving the car at idle with the ultragauge under the hood so you can monitor it. At the same time use your laser thermometer on a fixed point of the engine. See if the laser shows a spike when your UG does?

Did you ever get the coolant pressurized bleeder tool thingy? It sounds like steam pockets, but really I never had so much trouble bleeding a D1, that's why I never tried your funnel trick.

 

I'll have to try that trick this week.

And I never bought the vacuum for the same reason. We didn't do any bleed procedure on the motor we installed before this one and it had no troubles. Even the tech at AB said bleeding shouldn't be this much of an issue.

Unless my truck is just that damn stubborn.

 

Regardless of bleeding. Get a 180* stat