Rave isn't always perfect.

As far as I know, only the SAI radiators have that sensor. So while the description you've provided as to it's operation is accurate, it's only on Low Emissions Vehicles (SAI).

I just checked to be sure, and my 99 doesn't have the sensor below the lower radiator hose (which makes sense, because it's not SAI, and I don't think any 99 is) but my 2003 DOES have the sensor below the lower radiator hose, and it does have SAI (like most, but not all 2003 and 2004).

 

On a side note, is Silla a good radiator? Pretty hard to beat those prices but I wonder if it was made in China?

 

I have heard good things about silla. If you have a walk in store near you the price is $140 on them. Also the first thing they ask when speaking to Lucky8 is if your disco has secondary air for the sensor or not but I am sure this is just a made up ghost part that the doubters can't seem to find in the RAVE so it makes it not real I just wish someone knew if it would work for what I need rather than argue whether or not the part is real.

 

Everyone is right. If you have SAI, you'll need the radiator with the extra port so the sensor (which does not operate SAI, but does operate something else) has a place to go. Otherwise, you will have a check engine light on from no sensor, etc. Probably easier to determine if you have SAI than a small rad sensor tucked in at the bottom.

The RAVE does not have it as an SAI sensor, and the Bosch M5.2.1 ECU manual does not have it either, and it runs the SAI.

What this opens up is the possibility of using a radiator with the "extra port" and fitting that for a drain.....

 

But you missed the whole point of our "argument", we were trying to figure it out so that we know for next time.
If all we did was say "yes you need this" or "no you dont need that" then this forum would be pretty useless.

You learn by asking questions and debating the answer and investigating and getting input from others who know more and debunking those who think they know more.

I did not know that the SAI plugged into the radiator with a temp sensor, it made no sense to me why it would, but it has been explained, so now I know.

So yes, you need to buy a SAI radiator.

 

Just to chime in, I've noticed that some of the radiators available for Discos can be used with or without SAI. They are being offered with a port and plug. If you don't have SAI, leave the plug in. If you do, unscrew the plug and pop the sensor in.

 

I know the Silla has a plug but the company does not know if the threads will work for secondary air or not so I was just seeing if anyone had ran one or not. It would work as a drain like you said if you did not have the secondary air which would be nice to have.

 

I'd put money on that port being for the temp switch and NOT a drain. It's in the exact same place as the temp switch, and it's too high to be a drain. There would still be two or three inches of coolant in the radiator.

The people on the phone probably just are guessing.

 

so if you dont have SAI you could use tht port of a cooling temperture sender?

 

Use the port for what purpose? As Jafir mentions, it would not be a complete drain (my bad). If you have a temp sensor, it will be the one that throws codes P0126 (stat stuck open, temp differential too small), P1117 (temp below -27F coolant - will slush up then freeze), or P1118 (coolant above 284F at exit of radiator). I would not want to see P1118 as a stored code on a vehicle being considered for purchase. Users with Ultra Gauge must carry spare Depends in case this code is displayed while driving.....

While Rover radiator engineers decided 284F outlet temperature is too hot, and time to tell the driver about it, I'l bet the guys over in the head gasket design group had other ideas..... How hot would the coolant be inside the engine if the it is 284F "after" going thru radiator? See pages 320-322 in the shop manual.