Is the 180 stat a real Rover one? If you have a IR thermometer on hand, you can test radiator top to bottom, in a vertical line, with engine off, but warmed up. Colder on bottom by more than 10F is indicator rows plugged by something. Bottle of Water Wetter may buy you a few degrees.

 

Yes

Yes. Also, I was using the old radiator when I put the Irontite through it, so the Silla should be pretty fresh.


It has a motorad 180.

Debating whether to eventually go Genuine Gray or inline.

 

Stat is a Motorad, so 5-10 degrees more than the Rover is expected, but the spike to 210 yesterday seemed like a bit much...

Wouldnt lower row clog result in consistently higher temps or could it be the cause of the "high speed hot/medium speed cool" phenomenon?

 

Took a 20 min drive for lunch. Mostly 55mph highway and 5 min in the Taco Bell line.

Once warm, temps mostly at 195 with occasional bump to 197 or 199.

Also, flashing P0305 on startup again. Erased and didnt come back.

Will post again after the 95* rush hour crawl home.

 

Maybe some trash floating around clogging the tiny top holes in the thermostat.

The reduced volume radiator won't show up as a linear change in temperature. You'll have enough cooling slow and medium speed, but might run out of heat transfer capacity at higher speed. You have a lot of variables; the flow rate of coolant, the fixed volume and surface area of the radiator, the air speed thru the radiator, ambient air temp and humidity, and the heat produced by the engine. And all of that has to dance by a metal enclosed ball of wax inside the thermostat.

 

Drive home details:

- In 10-20mph rush hour for about 20 min. temps 201-204

- Right after the traffic thins Im going 60, relatively flat road and the temp pretty steady at 206.

- Going 65 up a big hill, temp goes to 210.

- Temp goes down to 204 as I exit and make the short neighborhood drive home

- Idled in the driveway for about 5 min and temp is steady at 206

It seems more or less ok unless it hits a hill.

Thoughts?

 

Let us assume it is a 180F stat. Fully open should be 15-20F above that. So let us say 200. So you are running above fully wide open. Seems like you have no reserve coolaing ability left. So going up a hill in really hot weather...

My D1 with a 180 stat runs at 183, up to 187 at freeway speed, with AC.

 

What does that mean?

Radiator cooling ability maxed out?

 

Assuming you are in the land of the Vikings, would not think it would be as hot as say south Texas. If you went on vacation, might be quite warm. IMHO if a cooling system is doing the job, it won't be a wide open thermostat condition normally. It may get to it once in a while, and under heavy use conditions.

On the other hand, when you installed a lower temp thermostat, you shoved down the operating temp. But we have not changed the 212F point for the electric fans to come on. But if running AC this should not be an issue, as the fan would be on anyway.

On the other hand, we have members with a D2 and 180F Rover stat, at making 182 at 65 mph. 20 - 30 degrees difference, but why?

 

Yeah, Im up north, so it doesnt get to 110 or anything When the air is a thick 95* though, it aint too pleasant! Is it pretty humid in Texas?

Sadly, I couldnt run the A/C in this heat cause it doesnt work. Fan blows, but air isnt cool.

I turned it on while it was idling in the driveway at 206 to see if the front fan would come on. Didnt move.

So you dont think its the smaller Silla?