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rovertone · 11th July 2015, 22:02

When towing up very long climbs in hot climes the coolant overheats and engine goes into safe mode. I thought I had solved the problem when I found that the 1st speed of fan was not working so fitted a gold resistor and checked that both speeds definately work ok.
Does anyone know whether it is possible that the 2nd speed works when called for by the aircon but doesn't when a high coolant temp demands it? I tackled a 6 mile constant 5% gradient in ambient high 30's and had to stop to give the engine a breather several times as I ground to a halt.

I was running with the OBD temp display and watched the temp climb fairly quickly up to 120 deg each time. it was a bit hairy with only half a hard shoulder and wagons roaring past but I am pretty sure that the fan was only running on 1st speed! I did also notice along the journey, no gradients, that I heard the 2nd speed come on (aircon call) and the coolant temp dropped from mid 90's to high 80's. On other climbs at lower ambient I watch the temp climb and have just managed to clear the tops with 115c showing. I have not lost a drop of coolant. I can find the fan trigger settings for 3 speed fan but not 2 speed so I am not sure at what temperature I should expect the engine to operate. At tickover with aircon on in traffic and 1st fan speed temp sits at 84deg.
As background to this:-
On a 3500 mile return trip to Portugal I have had the following:-
Burst radiator (suspect my fault abt 2yrs ago spanner slipped nicked fin)
Aircon leak (spanish mechanic damaged o ring on refitting)
Fan 1st speed not working (was ok in spanish garage was roaring away)
Heater hose holed (by bleed valve? disturbed when rad fitted?)
Aircon started whistling (when o ring changed noted condensor fins failing)
Crank pulley failed (little warning centre boss broke clean away)
Belching black smoke when under load or hard acceleration ( last 2 days)

All fixed except overheating and smoking, sorry for long epistle but any help would be welcome, apart from all this the car is brilliant!
Thanks Tony

11th July 2015, 22:02	#23
rovertone Gets stuck in Rover 75 Conne SE Auto CDTi Join Date: Nov 2012 Location: Redditch Posts: 673 Thanks: 185 Thanked 135 Times in 109 Posts	2 Speed Fan Poser will my woes end! When towing up very long climbs in hot climes the coolant overheats and engine goes into safe mode. I thought I had solved the problem when I found that the 1st speed of fan was not working so fitted a gold resistor and checked that both speeds definately work ok. Does anyone know whether it is possible that the 2nd speed works when called for by the aircon but doesn't when a high coolant temp demands it? I tackled a 6 mile constant 5% gradient in ambient high 30's and had to stop to give the engine a breather several times as I ground to a halt. I was running with the OBD temp display and watched the temp climb fairly quickly up to 120 deg each time. it was a bit hairy with only half a hard shoulder and wagons roaring past but I am pretty sure that the fan was only running on 1st speed! I did also notice along the journey, no gradients, that I heard the 2nd speed come on (aircon call) and the coolant temp dropped from mid 90's to high 80's. On other climbs at lower ambient I watch the temp climb and have just managed to clear the tops with 115c showing. I have not lost a drop of coolant. I can find the fan trigger settings for 3 speed fan but not 2 speed so I am not sure at what temperature I should expect the engine to operate. At tickover with aircon on in traffic and 1st fan speed temp sits at 84deg. As background to this:- On a 3500 mile return trip to Portugal I have had the following:- Burst radiator (suspect my fault abt 2yrs ago spanner slipped nicked fin) Aircon leak (spanish mechanic damaged o ring on refitting) Fan 1st speed not working (was ok in spanish garage was roaring away) Heater hose holed (by bleed valve? disturbed when rad fitted?) Aircon started whistling (when o ring changed noted condensor fins failing) Crank pulley failed (little warning centre boss broke clean away) Belching black smoke when under load or hard acceleration ( last 2 days) All fixed except overheating and smoking, sorry for long epistle but any help would be welcome, apart from all this the car is brilliant! Thanks Tony __________________ 2003 Mk 1 Connie SE CDTi Auto Monogram Mirage 2/Sandstone Leather 511th CDTi out of 4744 produced 9th in Mirage 2 out of 17 produced Also 2004 Rover 25 SXi CVT, 1999 Megane Cabriolet and still missing my 800 Fastback.