I did not see if you had checked your electric fan yet. I had the exact same experience with my Disco I but I'm not sure its exactly the same on your Disco II.

I'd bet my money on the electric fan or a partially clogged radiator core. It could either be the fan itself (failed fan) or the temperature sender that activates the fan when the temp starts to rise. The fan should be on when the A/C is running no matter what the temp outside or the temp setting on the car. If your fan is not running with the A/C on then your fan itself is likely bad. It may be okay but if the temp sensor that activates the fan is bad that could cause the fan not to come on when you are going slow. I am basing my discussion on the same thing happening to me. When running at speed, either rpm up or just going normal speed things were fine. When in heavy traffic going slow or stopped at lights it would creep up. I could turn on the interior heat and it would cool down telling me that it had something to do with heat removal capacity (radiator core or electric fan) since when I added another heat sink (the heater) it halted the rise. The Disco I as 2 fans and one had failed so it was not "extreme" but just noticable. My 2003 Disco II has only one electric fan. Just a thought. When its doing that run out and see if your electric fan is running. If the fan is not on turn on your A/C and see if your fan comes on, it should. I think the electric temp sender unit that kicks on the fan is pretty cheap and there may be a way in the RAVE manual to check it out. I'd check that route first before I started changing T-stats, etc.

Let us know what it turns out to be - "curious minds want to know"

Smokey73

 

GREAT post- thank you very much, friend.

The fan does indeed spin, but I haven't checked it with the AC on. All I know is that the last time it began heating up, I jumped out and looked, and it was blazing away.

Two days ago, I bled the coolant system, with my own twist. Instead of putting the cap back on the reservoir as soon as the hoses got hot, I really gave the engine hell. I wanted that pump spinning, to push any air stuck in the system out.

It hasn't heated up since then... AutoZone screwed my order up for the scan gauge, so I have to find another.. otherwise, I leave in the morning. Wish me luck!

 

Disco Mike told me that 215 was too hot. I've never seen anyone with a scanguage give high temps, because they know not to run these motors hot and can see exactly what hot is.

 

Yeah, I would run a 185 stat in that thing. These puppies run HOT.

 

Where can you get a "185 stat" for these rigs? I would be very interested in getting one of these for I live in south Tx we average about 100 degrees in the summer months!

Thanks in advance for the info...

Regards,

 

Well guys, after two weeks of driving such a way that was almost stressful (to keep the engine below 215 degrees), My Rover is fixed.

The shop determined it was the fan clutch, and it took them a week to get a new one. Now it idles nicely between 204 and 211, slowly rising, then falling, then rising, then falling.

It's a beautiful thing, ladies and gents.

 

Congrats Pat! Glad its fixed man, i know that has to be stressful!

 

Thank you much, Shane! I don't get stressed easily, but I was close when traffic stopped heading back through Chicago.

It went something like this (windows down, heat cranked):

Temp: 198
-4 seconds-
Temp: 204
-4 seconds-
Temp: 206
-4 seconds-
Temp: 210

Shift to Neutral
Rev to 2,500, hold for 5 seconds.

Temp: 198
-4 seconds-
Temp: 204
.... and on and on...